The Diagnostic Services

Browse some examples of our diagnostic tip content

Ignition Coil driver circuit in PCM

Crank Sensor fault

ASD Relay Failure

Distributor problems, no start or misfiring

Intake Gasket leaking into Valley

Timing belt jumped one or more teeth

Corrosion on connector #308

Cracked Flexplate/Flywheel

Timing chain jumped or loose, faulty cam position sensor or both.

Power steering switch leaking oil into O2 sensor harness

Carbon tracked plug wires

EGR valve hanging open

Intake manifold gaskets blown internally

Fuel Pump Cavitations causing air bubbles in the fuel rail

Valves sinking into the cylinder head

Re-route plug wires

Updated valve springs & Decarbonize valves

Oxygen sensor ground fault

Most common evap failures

Clockspring/horn voltage shorted to TPS/Cruise circuit

P0303 Fuel injector heat problem

Cam gear alignment pin broken or jumped timing belt

Wiring harness under intake melted

TPS harness shorted

Erratic TPS causing Fuel injector codes to set, erratic surge at idle

Bad battery causing stalling after startup

VSS shorting 8 or 5 volt supply to cam and crank sensor.

PCM flash update for spark knock/pinging

PCM reflash/ erroneous code P1763

Erroneous P0107, PCM reflash

Bucking/Surging at high RPM under Wide Open Throttle

Erroneous code P1398

Slightly rough idle when warm, no codes

Erroneous P0456, with no leaks found.

P1499 stored with possible overheating.

LDP vent valve with possible codes P0442, P0455, P0456

Long Crank, Hard Start

Erroneous P0116 caused by software issues.

Idle fluctuation or surge with possible misfire codes P0300 through P0304

Broken wires at Air Intake Temp sensor connector

New TPS and/or New throttle body unit

Long crank after 10-60 second run time on initial cold start.

New O2 sensor ground wire from sensor to PCM

Engine stumble or miss at 2 minute intervals

Updated exhaust valve springs & Decarbonize valves

Check engine Light on with Erroneous Misfire DTCs

CEL on with possible codes P2302, 2305, 2308, 2311, 2314, 2317

Light load misfires/ Carbon build-up on exhaust valves

Cracked cylinder wall on cylinder #8

Updated TPS

Erroneous P1594 with possible battery/charge light on intermittently.

Spark Knock. Especially with hot ambient temperatures.

Ignition Coil Update for P1320

Wiring harness breakage

P0136 O2 sensor Update

Updated TPS and Possible Transmission Control Unit

Insect nest in Evap vent hoses or components

Harness damaged by rubbing power steering pulley

Spark knock on hot re-start as key is released.

New ECM to solve spark knock, especially with high ambient temperatures.

Water entering the evap system, Water separator valve available.

Intermittent no-start or stall or run rough, especially after a hot soak.

Hesitation at cruise speed with light throttle application.

Wiring harness broken at back of engine.

ECM connector and/or O2 sensor defect.

Dirty or damaged MAF sensor.

O2 sensor replacement and PCM re-flash

ECM re-flash for P0420

P0505 stored with no drivability complaints

Stalls or idles low in gear after a cold start.

Traction control light on. P1211 and or P1212 stored

Surge at 40 to 60 MPH

P1605, TCM communication fault

Hesitation between 2000 and 3000 RPM with Manual Transmission

Lack of power on acceleration, A/T only

Dirty/damaged MAF sensor.

Accelerator stopper update for P0228 and P1228

Misfire and/or lean bank 1 or 2, injector faults

Hard start when engine is warm, possible P0340 or P0345

A/F ratio sensor codes with possible exhaust ticking noise.

ECM software update for DTC's P1031, P1051, P1148, P1168

ECM re-flash for P1274 or P1284

ECM re-flash for P0442 and/or P0456 with no leaks found.

Knock sensor or harness Causing P0325

Slow crank causing P1335 and possible hard start

Crank-no-start caused by anti-theft system.

Canister vent valve fault

Speedo Head causing P0500

EGR ports and BPT valve

MAF contamination or sluggishness.

Miscalibration of O2s

Hesitation after corner

O2 sensor failure

Plug wires cracked or burned.

EGR valve hanging open.

Intake manifold update.

Interference at ECM causing false 1336

Moisture in spark plug wells causing misfire

ECM update for false P0100

PCM update for MIL / Stall with P0446

Connector corrosion at ECM connector.

Contaminants in Evap system

False P0300

Causes for P0335

Crank no-start, or long crank after cold soak.

Erratic idle or won't idle.

MAF issues with possible P0102 or P1102

ECM problems with below freezing temperatures.

O2 sensor causing drivability and multiple possible codes.

Ignition coil resistor update.

ECM reflash for P1031, P1051, P1148, P1168

Updated Tube, ECM and Temp sensor for P0400

Updated evap pressure sensor.

Diode harness repair for P0505

P1110 VTC solenoid diagnosis

Updated torque converter for P1550

P0300 stored, but no misfires found & no customer complaints

P0505, bad IACV-AAC valve

Possible ECM fault for P0137

CKP sensor update campaign

Hesitation on light acceleration with cold engine.

ECM update for P0134 and P0171

Low power, vehicle starts off in 3rd gear

Recall campaign for cam and crank sensors

EGR valve problems

ECM software update for P1444

ECM reflash for P1278 and P1279

ECM update for P0442 and/or P0456

ECM update for P0462

ECM update for P1031 and/or P1148

EGR tube update.

Water intrusion in evap system.

ECM update for P0505

TPS update for P0731,732,733

ECM update for P1031, P1051, P1148, P1168

Water in canister from launching a boat.

Water in distributor cap

Damage to AIT Sensor harness, updated bracket.

Updated IACV-AAC valve for P0505

Updated EGR valve

Broken wire at fuel temp sensor.

Ice forming on injector tip#3

Vacuum cut valve bypass valve installed upside down.

Clutch slippage causing P0500

Rust in metal pipe damaging purge volume control valve

EGR port cleaning for P0402

ECM update for P0420

EGR tube update for P0402

Fuel tank problem

Idle surging or high with clutch depressed while moving.

Wrong speedo gear installed at factory.

Several updated parts to correct P1491.

Water dripping onto ECM

Poor ground between intake and RH cylinder head.

ECM update for idle surges with manual transmission.

P0400 or P1400 on vehicle without EGR valve.

Updated fuel injectors, ECM, and AAC valve for hard start in cold/high altitude climates

Intake casting flaw causing P0300 through P0306

Updated EGR tube for P0402

MAP/BARO switch solenoid valve fault

ECM update and O2 replacement

ECM update for P0420 and P0430

ECM update for P1441

ECM update for P0138, P0139, P0158, P0159, P1147, P1167

BPT valve hose cracked or deteriorated

TCM update to solve P0745 fault

Re-flash the TCM for P1774, P1730, P1731

ECM update for P1278, P1279, P1288, P1289

ECM update for codes P1031, P1051, P1148, P1168

Cold engine miss fire

Oil on optical sensor or bad distributor

Plugged EGR ports causing misfires

Blown intake gasket, usually cylinder #4

ECM board corrosion due to foam deterioration

NATS system failure

Mixed up sensors for P1140 or P0340

Two Stage Fuel Pump Relay

Engine Stall-Idle/Decel

Broken wire in O2 sensor harness

High Failure rate of CMP sensors

Sludge in engine causing VVT problems

Start signal fuse missing or blown

Charcoal canister coming apart

2 Repairs for P0740

P1361 and P1381 Both stored

Distributor cap contamination

Ignition faults causing P1381

Updated A/F sensor and PCM for P1164

Evap solenoid failures

False P1149

Fuel pressure regulator and vacuum hoses for P0171, P0172

Slight hesitation when accelerating slowly from a complete stop

EGR port clogging recall

Possible Moisture freezing in map sensor

Possible false misfire code set

Fuel injector/ PCM update for P0133

PCM update for P0128 and P1486

Long crank after Hot soak in winter months only

PCM update for P0128

Updated Drain joint for Evap canister

Updated air intake breather pipe

PCM reflash for P0420

PCM update for P0606

Jump-starting a vehicle can set P0606

PCM update for P0301 & P0305 or P0302 & P0306

PCM update for Ping/Spark Knock on acceleration

Hard start or long crank time

Connector fault causing P2135

Fast Idle

PCM update for P2195 and P2197

No start or starts and stalls unless throttle is partially depressed

PCM software update for false misfire codes.

Rocker hold down clip update

Engine harness rubbing on intake manifold bracket

Linear solenoid and passage contamination

PCM update for false misfire detection

PCM update for P0133

Mil on with P0740 after transmission replacement

PCM update campaign by Honda

Torque converter deteriorating causing a P0740

Fuel pump connector corrosion

Intermittent stall when coming to a stop, Vehicle does re-start

P0730, Vehicle will not move in drive

Bad solder joint in ELD

Hard start, no-start, long crank, start/stall after fill-up with gas

Camshaft endplay causing rattling and P1361/P1362

VTC solenoid stuck & PCM update

Internal PCM failure

Software update for P1440, P1679, P1446, P1449

PCM update for P1420

P1021 stored after an oil change

MIL on with P1600 or P1601

Misfire, hesitation, surge at 20 to 60 MPH

Electro-Viscous fan clutch fault

Carbon Build Up

EGR Passage Burn Through

Long crank time, fuel pressure regulator leaking

Ignition Module and/or ignition coil causing misfires

Missing PCV O Ring

Aftermarket Alarm or wiring short under dash

TCM fault for P1768 AND P1773

Flush transmission for P0740

ECM update for no-start in very cold ambient temps

EGR valve causing surging, bucking, hesitation

Fuel fill pipe threads bind the fuel cap and do not allow it to fully seat.

MAP sensor connector pins fretting

Plugged EGR ports can cause misfiring, surging, pinging, spark knock and/or high NOX readings

Low or old oil causing VTEC codes

Coil causing Tach to bounce erratically

Crank sensor wiring cut by alternator belt

Distributor, Coil, Igniter failure

PGMFI Main relay has very high failure rate

Ignition switch recall

Common causes for surging at idle

EGR hoses swapped at solenoid

Purge flow problems

Coolant switch and VTEC switch connectors switched

Ignition coil causing P0725

Plugged EGR ports causing misfires

Reduced EGR Flow

IAC valve sticking or clogged with carbon.

Crank-no-start with immobilizer key

Hesitation/Stall-Fuel Tank Baffles

Decel Stall or Long Crank Time

Harness Damage at Accumulator

Idle Surge on Cold Start 3.1

PCM Diode Causing Failed Self Test

Ignition switch fault

ECM harness damage

PCM shorted internally, can not control IAC valve

Poor body or TPS grounds.

PCM update for false misfire codes

Garage kept vehicle generates P1441 in freezing weather

Too much programmed ignition timing causing pinging below 3000RPM

Sticking power steering pressure switch causing intermittent high idle.

Fuel Tank Pressure sensor shorting 5 volt signal

Updated TCC solenoid and ground wire

Recall for purge hose cracking near exhaust

PCM software update for pinging or spark-knock

Grease on APS causing high resistance

PCM update for cold stall when shifting from park to drive.

Mass Air Flow (MAF) Sensor Contamination

Vacuum Leak on PCV hose assembly.

Wiring harness breakage near PCM

Fuel Pump Driver Modules and/or fuel pump

Fuel pump O-Ring seal update for P0440 and P0442

PCM update or Torque converter replacement

EGR valve causing surging or hesitation

Two-way valve orifice update for P0451

Faulty IAC valve setting MAP code P1129

Broken wire at Power steering switch causing idle surge

Corrosion at fuel pump connector

Loose terminal in fuse box to fuel pump

Moisture freezing in the ETCS relay

Speed sensor drive gear worn

Lean codes from oil problems

Vacuum leak at pcv hose causing lean codes

Clogged EGR ports

PCM update for false P1164

Throttle body defect causing P0122

PCM update and VTC solenoid replacement for P0341

Stumble or stall when coming to a stop

Mud in purge line and or canister

PCM update for P1163

Safety recall for shift cable

Possible software problem for P0128

Faulty trans temp sensor setting P0710

PCM update for P0420

Intake manifold seals causing lean codes and rough idle when cold

MAF causing multiple problems

EGR valve and passages causing codes

Lower intake gaskets are prone to leaking vacuum on this engine

Fuel level sensor fault, possible fuel gauge inop

One or both cats plugged causing drivability issues

O2 connectors switch after transmission or engine removal

Internal PCM failure for P1618

Possible tank pressure sensor causing P1441

Ignition coil #6 is different than 1 through 5

Incorrect spark plugs causing Ion sensing codes.

EGR valve causing P0172 and P0175

Valves too tight causing stalling or rough idle/misfires

False misfire detection by PCM

TCM update for P0740

Faulty TCM causing P1706

Harness corrosion causing P0132

Fuel cap binding when tightening and may not seal properly

PCM update for P0133 and/or P0153 O2 codes

PCM update for P1106

Ignition switch recall for stall/no-start

Warranty extension for clogged EGR ports

PCM update for P0128 and or P1486

Long crank after hot soak in cold climates

PCM update for P0301 and P0305

PCM software update for P2195 and/or P2197

PCM software reflash for misfire codes

Try flushing transmission for P0715

False misfire detection for P0304 and P0306

VTC solenoid sticking & PCM update

PCM software problems causing P0128

PCM reflash for P1122 and P1163

Bypass solenoid with sluggish response

Carbon build-up on intake valves

EGR intake port clogging with carbon

Valves tightening up and clearance reduced

Faulty Spark Detection Module

PCM software update for P0456

Hanging IAC valve causing MAP codes

PCM update for P1441 with ¾ tank

Ground wire for TCC solenoid

Ping or detonation below 3,000RPM

Ignition coil and harness update

Downstream O2 harness cut by drive shaft

Fuel tank liner deterioration

O2 heater shorting ASD relay fuse.

Shorted CKP,CMP, or VSS causing no communication with PCM

Possible blown fuse for O2 or other components

Corrosion on the transmission solenoid pressure switch and harness

PCM update for false P2096 and/or P2098

PCM update for P2302, P2305, P2308, P2311, P2314, P2317

Faulty TCM causing multiple transmission codes

PCM software update for O2 heater codes

Transmission speeds sensors causing transmission shifting problems and MIL

O2 sensor causing Hesitation, misfiring, rough running and possible MIL

Rust in fuel rail clogging injectors on returnless fuel systems

Relearn crank variance

Oil pump drive shaft seizing causing no-start or primary ignition codes

Intermittent internal coil pack failures

Flex Fuel Module fault

Fuel pump module seal leaking at tank.

Internal fuel pump sealing ring causing fuel pressure bleed off.

Bad O2 or O2 ground can cause P1762 and/or P1757

PCM update for P0443

Updated valve body cover plate.

PCM reflash for P0116, P2172, P2173

PCM update for rough idle and MIL

Updated throttle body for P2110 and/or P2118

Dirty throttle plate or dirty/wet air filter

PCM reflash for P2097 and/or P2099

Faulty PCM causing transmission codes

PCM update for EGR failure codes

Erroneous P0335 and/or P0340

PCM update for idle surge and lean codes

PCM causing intermittent drivability problems.

Gas cap strap problems

Erroneous P0460 stored

Worn distributor shaft bushings or gear.

Charcoal canister disintegration causing P0441.

Clogged converter causing no-start or low power.

PCM reflash for injector codes

Fuel injector leak down causing hard start/long crank, rough idle.

Governor pressure sensor problems.

Faulty speed sensor causing P0500 and speedo problems.

Evap hoses cracking and splitting

Shorted sensors causing No-Bus on instrument cluster and possible no-start.

Condenser fan fault and blown fuse

Faulty NVLD causing evap codes

Transmission causing stall on hard deceleration

Crank, no-start after replacing engine or crankshaft

Steady of rhythmic misfiring under a load and transmission codes stored.

Cam position sensor and/or synchronizer fault

Flex Fuel index has learned the wrong value

Ignition coil faults causing misfires on COP ignition systems

Bad DPFE sensors can cause drivability issues

Flash update for Catalyst System codes

PCM flash for test time change

PCM Flash for Catalyst System codes

Speed limiter sets codes.

Input Speed Sensor Wiring

Secondary air injection pump failure

Ignition switch

EGR valve sticking open

Splice 116 corrosion.

Anti-theft enabled on a vehicle that does not have anti-theft.

Rocker Pedestal is broken.

Bad Cam position sensor.

Ignition switch causing BUS communication issues.

Bad solder joints on instrument cluster.

Fuel pump failures

EGR valve and position sensor failures

Injector causing a hard to find misfire

DPFE sensor shorting out causing PCM to shut down

Misfire and theft/ABS/air bag/temp or other dash lights flicker

Intake gasket and IMRC shaft seals leaking.

Dirty throttle plate causing intermittent stalling or low idle

Faulty distributor or Photo cell CMP.

Timing belt jumped one or more teeth.

EGR backpressure transducer failure

Common causes for instrument cluster Inop.

Excessive carbon build-up on intake valves.

Fuel pump failing after a lengthy drive.

Leak Detection Pump failure

Timing belt jump or cam gear pin sheared

Carbon deposits holding valve open

Poor ground connections

Control valve in top of tank not closing, flooding canister after refueling vehicle.

Starter solenoid fuse blown.

Defective crank sensor causing cam sensor codes.

Broken wires in steering column near ignition lock cylinder.

GM ignition failures WITH DIS ignition.

PCM has high failure rate.

Passlock common failures

Cam sensor or magnetic interrupter failure

Carbon build-up on intake valves causing cold start issues

Poor ground splice under carpet near drivers door.

P0325 after PCM replacement.

Shorted oil pressure switch.

PCV valve missing or damaged causing codes

High failure rate of PCM causing P0341 or 341

Charcoal canister deteriorating.

Spark plug wire heat shields causing problems.

Rust or corrosion build-up on coil tower

Hidden fuses.

Instrument cluster connection.

Catalytic converter is partially or fully plugged

PCM causing surging around 40to 60 MPH

Supercharger gasket leaking vacuum.

Two crank sensors on this engine

Rough running or no start after intake gasket or head job

Injectors causing rough idle or mild misfiring at cruise.

Hesitation or lack of power, may be intermittent.

EGR hanging open slightly and intermittently

Intake gasket blown internally causing rough idle or misfire

EGR port at throttle body plugged.

EGR installed backwards causing P1406

Battery disconnect or dead battery causing low idle or stalling at stops.

Throttle stop has been tampered with, causing P0507.

CKP causing hard start with possible kickback or backfire.

PCM reflash for P0446 evap failures.

Fuel tank sending unit O-ring seal leaking from factory.

Vent valve harness chaffed or wires broken.

Fuel pressure is critical on CSFI systems.

Carbon build-up on injector poppet valves.

Injector assembly or internal fuel pressure regulator leaking.

Light misfire or shudder after injector assembly removal or replacement.

Cam lobes spun on camshaft.

Crank sensor harness shorting intermittently to exhaust or power steering bracket.

MAF sensor contamination.

PCM reflash for P1404

Wire broken to IAT sensor.

Leaking intake gaskets when cold.

High rate of timing chain faults with this engine

TCC solenoid sticking.

PCM location allows water intrusion into PCM and connector.

EGR valve and/or solenoid.

P0440 will not clear out of memory after repairs.

Rough running after head gasket replacement.

Faulty TPS/ECT sensors

Crankshaft variation learn procedure.

Fuel composition sensor faults.

Bad air pump and/or check valves

Distributor adjustment or worn drive gears.

Coil cover assembly causing misfires.

Timing chain problems.

Coil cover assembly causing misfires and no-starts.

High rate of timing chain and tensioner failure.

Extreme oil pressure keeping valves open.

Instrument panel cluster shorting communication lines.

Bad ground at bellhousing.

Cam sensor code, but vehicle does not have a cam sensor

O2 sensor problems causing hesitations, stalls, rough idle.

MAP sensor vacuum hose.

Plugged catalytic converter.

Oil pressure switch causing fuel pump issues.

CKP sensor connectors switched

CKP sensors causing intermittent stall, hard start or no-start

MAF causing hesitation on initial acceleration

Fuel tank is prone to cracking and leaking vapor at the filler neck

Plugs AND wires must be replaced when carbon tracking is found.

EGR valve causing problems

Plug wires are causing intermittent stall, especially when hot.

TPS or FTP sensor causing intermittent high idle.

Park/Neutral switch intermittently defective.

Crank sensor/ Control Module faults.

Failed input speed sensor.

Intake manifold pop-off valve leaking.

Incorrect valve timing or timing chain gears switched

Intake manifold gaskets or backfire valve leaking vacuum

AIR Check valves sticking closed

Faulty Opti-spark unit

Coil wire/Ignition coil faults.

Air pump failure

Specific problem with aftermarket plug wires.

IAC and ignition module connectors accidentally switched.

Transmission pressure control solenoid fault.

Debris plugging the 2-3 shift valve/solenoid.

Slightly higher than average injector problems

Poor connection at transmission main harness connector

TCC pulse width modulated solenoid fault

Under hood wiring harness junction box failure

Transmission fluid pressure switch.

Shorted harness causing fuel pump fuse to blow.

PCM flash update for P1441.

Wiring harness issues

PCM reflash for P0107.

Harness tension causing P0503.

Updated crank sensors.

PCM reflash for P1575.

PCM reflash for P0171, P0174

High rate of spark plug wire failures.

Wiring corrosion to EEC or Fuel pump relay.

Steering linkage pulling on crank sensor wires.

EGR ports clogged.

Inertia switched tripped.

Connector 123 rusted/corroded terminals.

PCM reflash for P0420 and/or P0430 catalyst codes.

Fuel pump wiring harness chafing at fuel tank area.

PATS system fault with bad or un-programmed key.

Crank sensor connector issues.

Broken valve springs.

Coil pack failures

Defective PCM causing O2 sensor heater circuit codes.

Bad intake gaskets and/or cracked manifolds.

Fuel pressure regulator hanging or leaking internally.

Octane adjust bar missing.

Fuel injector driver shorted in PCM.

Traction control causing severe loss of power in turns.

DPFE faults causing low EGR flow codes.

DPFE sensors and Alternators setting cam codes

EEC or computer power relay.

Relay module defective.

Faulty ignition coil packs.

Bad ECM causing rough idle/misfiring.

Balancer slipping on crankshaft.

Dirty throttle plate causing stalling or low idle.

EGR valve sticking closed

EGR position sensor gasket missing or torn.

Misfire codes after crank pulley removal or replacement.

Wrong ignition module installed.

Failed DPFE connector.

Updated harness for TPS for high idle condition.

Connector C116 power supply to relay module.

Repeated failure of relay module on the fuel pump circuit.

Coil and cam sensor connectors are switched after engine work such as head gasket replacement.

IMRC motor failure

Bad IMRC motors or stuck intake manifold runner shafts.

Defective IMRC unit.

EGR ports clogging and causing misfires.

DPFE hoses reversed

Bad or mis-adjusted camp sensor.

ECT causing rich condition and rough running

Short inside tank at fuel pump assembly.

CMP synchronizer installed 180 degrees out.

Wiring harness rubbing on AC lines.

Evap codes caused by leak at FLVV or OPR valve.

Bad Air injection pump

Fuel pump causing a surging at cruise speeds that can feel like a misfire.

Vapor management valve is a common evap failure item.

PCM reflash for P0442

Faulty ECT causing intermittent no-start or poor running.

Wiring harness chaffing at transmission housing.

Back pressure transducer hose burned through.

Distributor optical wheel causing hesitation or misfire when warm.

Air injection failures.

Poor PCM grounds.

Broken valves springs and blown head gaskets.

Blown fuse or bad air pump relay.

Air pump relay defective.

TPS causing intermittent High Idle

O2 connectors accidentally swapped.

VSS has a moderately high failure rate.

How to re-time the Ford CMP after shaft failure.

Chirping noise coming from under the hood.

Humming or vibration from the air cleaner or intake area.

Intermittent wiper, washer or brake light operation.

Intake manifold cracking and leaking coolant.

Loss of radio, power windows, etc. when transmission is put in reverse.

The cruise control is inoperative.

Noises from rear differential area.

Fuel Pump or Fuel Pump Driver Module failure.

Resetting Honda SRS lights.

PCM reflash for P0316 and/or P0191

Vacuum leak at PCV valve hose or elbow.

PCV hose leaking under upper intake manifold.

Water in bulk connecter under drivers seat causing multiple issues.

Power window, lock and mirror problems.

Squealing or screeching from under the hood.

Engine running roughly or stalling. May appear to be locked up.

Intake gaskets leaking on vehicles with plastic intake manifold.

Noise from steering column when turning.

Flex Fuel Sensor faults.

Moisture intrusion in 40 pin connector under drivers seat.

Excessive fuel pressure after engine work has been performed.

Low or no clutch pedal after servicing system.

Bad fuel rail pressure sensor.

Multiple electrical problems

ABS engages at low speeds and dry road conditions.

Rough running when cooling fans turn on.

Drive belt tensioner is bad.

Banging from the intake area.

Power steering fluid overflow/bleeding the power steering system.

PCM reflash for Lean and rich codes.

Cruise control and horn are inoperative and the air bag light is on.

Shudder or shimmy in steering after towing or repairs.

PCM reflash for spark knock

P1635, P1639 after PCM replacement.

PCM reflash for Misfire codes.

Fuel pump continues to run after engine is shut off.

Check engine light on with various codes and symptoms.

Only the third brake light illuminates.

Distributor out of synch causing P1391.

Balancer keyway broken causing cam/crank sensor phase to be incorrect.

Wiring harness problems and factory warranty extension.

The vehicle under hood wiring harness is cracking and falling apart.

Wiring harness shorting on the ignition module bracket

Rotating engine counter-clockwise can cause timing chain problems.

Camshaft dowel pins sheered.

Distributor or ignition coil failure.

TPS and MAP sensor connectors swapped accidentally.

Air intake hose broken or split.

MAF sensor faults.

Distributor cutting out when warm.

EGR ports plugged behind throttle body.

Engine fuse blows when engine is cranked.

Faulty seat belt buckle switch.

Power windows and locks inoperative.

SRS light on, “Internal failure of SRS unit”

Defective IAC valve causing high idle speed.

Weak coil or burned rotor button.

Throttle stop tamper or bad/out of adjustment TPS.

Defective EGR boost sensor

Harsh stumble with any but light throttle.

Leaking upper intake gaskets causing rough idle and lean codes.

Failed coolant temp sensors causing rich conditions and rough running.

Fuel gauge reads inaccurately on flex fuel vehicles.

Low tire pressure light is on.

Fuel smell inside cabin.

EGR passages behind throttle body partially plugged.

Defective IMRC actuator.

Wiring harness rubbing on engine lift bracket, firewall side.

Octane adjust bar has been removed.

Rangers & B Series Mazda have high MAF sensor failure rate

Rear Diff sensor failure.

PCM reflash for catalyst efficiency codes.

Bogs or cuts out with heavy throttle due to lack of fuel pressure.

Connector C120 problems with corrosion and poor contact.

Whining or buzzing noise coming through speakers.

Shifted flexplate causing low power or possibly even a no-start.

Spark plugs breaking off in cylinder head.

Wrong IAC valve installed.

No-start after engine swap.

Timing belt installation faults.

Timing belt, flexplate, exhaust cam gear or balancer faults.

Faulty VCT solenoid or cam gear.

Wrong part number for DPFE sensor.

New crank sensor connector wired in reverse.

Wipers stop at the top of the windshield.

Blower motor inoperative.

Check valve damage from engine overheating.

PCV hose leaking at back of engine.

Fuel rail pressure sensor or faulty fuel pump module.

Wrong PCV or cracked PCV hose.

Low coolant light on with reservoir full.

Voltage drop across inertia switch.

Engine overheating with cooling system full.

Cracked intake runner on cylinder #4

Excessive carbon causing misfire codes and rough idle.

Stall or loss of power on turns.

Updated TPS and pigtail connector

Wiring harness short near engine lift bracket near fuel rail

Cover under distributor rotor causing misfire.

Rotor button failure causing no-start or harsh cut-out, hesitation.

Distributors fail frequently on this vehicle.

Faulty coolant sensors.

Poor connection at C101, power feed for injectors.

Faulty ignition switch causing no-spark.

Incorrect PCV valve or leaking PCV vacuum hose.

Cam position sensor failure.

Harmonic balancer keyway damage causing low ignition timing.

Air flow meter is drawing down the 5 volt reference.

Weak distributor magnet

Fuel Pump Pulsator leaking

Blown throttle body base plate gasket

Partially plugged exhaust causing MAF codes

Blown ECM 1 Fuse

Blown ECM B Fuse

EGR valve sticking open

Intake gaskets leaking, usually when cold

The AC compressor clutch does not engage.

Constantly blowing fuse #29.

Brake pull to either side.

Fuel pressure spec is wrong.

Plugged catalytic converters caused by sticking fuel pressure regulator

Engine stalls when headlights are turned on.

Oil pressure gauge does not immediately rise upon startup.

Fuel gauge is inaccurate.

Four wheel drive is inoperative.

Engine cranks to slowly to start

Distributor problems causing erratic running. Runs much better with spout connector unplugged and engine at base timing.

O2 signal shorting to voltage due to corrosion.

Vehicle over-speed shut down engaging at any speed or when put into gear.

Faulty map sensor causing rich conditions.

Timing chain guides broken, chain jumped

Faulty vapor management valve

Misadjusted cam position sensor or synchronizer assembly.

One time use spark plug wires.

O2 sensors connectors accidentally switched.

Shorted O2 harness to exhaust.

Cam position sensor and synchronizer faults.

EGR tube O-ring Seal.

Crank-no-start faults.

Ignition coil harness shorting at AC line.

O2 sensor failure when hot

O2 heater driver circuit burned out in PCM.

Low coolant light is on.

Blown fuse causing multiple codes.

Valves recessed into the cylinder head.

High side AC pressure is high with little refrigerant in the system.

Damaged throttle body by cleaning.

AC blower motor has reduced efficiency.

Intake manifold gasket leaking coolant.

Defective or mis-adjusted CMP sensor/synchronizer

O2 sensor harness shorting out and blowing fuse.

Leaking intake O-ring gaskets

Fuel rail debris and regulator

Bent connecting rods due to blown intake gasket.

Repeated pinion seal failure.

Smoke coming from the steering column.

Heater hose leaking onto #4 ignition coil.

A/C condensation dripping on oxygen sensor.

EGR valve hanging slightly open

Cylinder Head Temperature sensor faults

Transmission causing hard stumble or stall

Spark plug blown out.

Wrong O2 sensor replaced.

Day time running lights inoperative.

Steering wheel is hard to turn at idle.

Do not strip the spark plug threads!

Low fuel pressure after pump replacement.

Do not machine 4.6L and 5.4L cylinder heads.

Water intrusion into GEM module.

Performance chip causing P0605

Shorted harness on top of engine.

Correct spark plugs are crucial.

Erratic gauges and other interior accessories.

Front differential will not engage.

Grinding from front differential.

Overheating or fluctuating temperature after water pump replacement.

Vehicle will not start after replacing fuel pump.

AC inoperative after condenser replacement.

Bogs or holds back on acceleration.

Snap or clunk from front differential assembly.

Repeat oil leak at the timing cover.

Cannot bleed rear brakes after replacement of master cylinder or ABS control components.

Weak ignition coil

Poor grounds causing no start,hard start, or kick-back.

Suspension noise that is difficult to locate.

Thump from back of vehicle when stopping.

Air bag light comes on after re-installing air bag.

Air bag codes B0051, B0053, or B1051, B1053, or B1151, B1153.

Coolant temperature sensor removal.

Multiple issues including MIL or ABS lights illuminated, stalling or other electrical issues.

Tire inflation warning false activation.

Blower motor does not work on one or more speed.

SIR system codes will not clear.

ABS system setting code C1238.

ABS system setting code C1241.

ABS system setting code C1242.

Pass through connector burned or corroded.

ABS activates at low speeds.

The dome light stays on all the time.

The turn signal flasher continues to operate after the turn signal switch is turned off.

ABS light comes on at low speeds.

Brake lights do not work.

Temperature gauge is reading hot.

All lights at the front of the vehicle are inoperative.

P0125 is an A/F or O2 sensor code, not coolant temp

Low coolant light comes on when the level is full.

Wrong Bank sensor replaced.

Timing belt jumped or installed improperly.

Engine overheats.

Bad ignition coil in distributor.

IMRC linkage rods or vacuum motors defective

Vacuum switching valve causing no or low EGR

Vacuum switching valve causing too much EGR flow.

Failing ECT sensor

EGR valve causing stalling when coming to a stop.

Bad idle switch or carboned throttle plate.

Shorted Capacitor in distributor

A/F Ratio sensors are not oxygen sensors.

Idle speed control motor not working when cold

Daytime running lamp indicator on dash is flashing.

Engine or transmission whine at 2800-3200 RPM.

Timing chain rattle after repairs.

Blows fuel pump or ECM B fuse.

Shorted wiring in the trunk

Multiple causes for P1300, P1310

Evap hoses accidentally swapped.

Hose pulled off canister closed valve

ABS codes C1246 and C1286.

The 4WD fuse is blowing or the front axle will not engage.

AC does not operate when the button is pushed.

A/F ratio sensor causing lean codes

Vacuum switching valves are common evap problems

PCM driver damaged for evap components

Incorrect engine installed.

Idle speed control motor faults when cold.

Broken tooth on the crank gear.

Most common cause of P0446

MAF sensor hotwire contamination

Fuel pressure regulator failure

EGR position sensor causing surging, misfires

Faulty IAC valves are somewhat common

ABS code C1241.

ABS code C1242.

ABS code C1244.

ABS code C1245.

ABS code C1246.

ABS code C1248.

ABS code C1251.

ABS code C1252.

ABS code C1255.

ABS code C1256.

ABS code C1274.

ABS codes C1235, C1236, or C1237.

ABS codes C1231, C1232, or C1233.

ABS codes C1225, C1226, or C1227.

ABS codes C1221, C1222, or C1223.

A/F ratio sensors causing extremely rich condition

EGR valve hanging open intermittently

EGR temp sensor coated with carbon

Aftermarket timing belt causing trouble codes.

Fuel injector faults

Knock sensor sub harness faults

Firing order wrong after tune-up or coil/wire replacement

Timing faults causing P1346, P1351, P0335, P0340 or other codes

Security system causing no-start.

AC blower motor only works on high speed.

Timing belt or crank gear

Intermittent horn operation.

The ABS light is on and the cruise control does not work.

Multiple electrical accessory failures.

O2 sensor identification

Rev limiter engaging while driving.

Injector connectors swapped.

Hoses switched at the purge valve

Canister causing evap codes

Non-electronic struts installed.

Vacuum hose to map sensor

COP ignition causing misfires on the DOHC 3.0

Poor ground at MAP sensor

Common EGR faults

Crank sensor or reluctor ring damage

Poor ground circuits

MAF sensor causing low power and lean codes

ABS codes will not clear.

Intermittent cruise control operation.

Spark plugs causing misfires

Wiring break or short at firewall.

Variable valve timing issues

Vacuum hoses installed wrong

MAF sensor causing rich codes

EGR with intermittent faults

Must use dual strap spark plugs

EGR system failures

Timing belt alignment

Crank sensor issues

MAF sensors fail frequently

Hose disconnected at air filter housing

Incorrect or wrong weight oil

MAF sensor problems on Hybrid

Air flow sensor faults

O2 sensor vs. A/F sensor

Sensor locations

Small glitch in TPS

Tight valve clearance

Dual strap plugs

Crank bolt causing severe power loss.

Damaged or mis-positioned reluctor

O2 sensor harness shorted on exhaust

Valve timing off

Check gauges message displayed.

Power door locks do not operate properly.

The blower motor is inoperative.

The battery goes dead after a short time.

The engine overheats after replacing the thermostat.

ABS pump operates at low speeds.

Shaking from power steering at idle.

Change brake pad message displayed.

Rear brake shoe wear.

Updated timing belt tensioner.

The blower motor only runs on the high setting.

Engine will not run after timing belt replacement.

The mode door is stuck in defrost.

ABS light is flashing after ABS controller replacement.

Transmission goes into limp-in mode.

The tachometer is inoperative.

The digital odometer does not work.

The speedometer is inoperative after replacing the TCM.

Air flow Meter spring is broken or weak

Air flow meter tamper or attempted adjustment

Wiring harness rubbing between intake manifold

Knock sensor harness problems

Computer hitting over-speed shutdown around 55 MPH

Air Flow meter shorted internally

EFI main relay fault

IAC causing high idle speed or surging at idle

Bad Thermo time switch

Faulty ignition coil causing multiple symptoms

Distributor indexing incorrect

Common EGR failures

Intermittent problems with fuel pressure regulator

Timing retard due to knock sensor

EGR sticking intermittently

Faulty canister closed valve

The engine will not run after battery discharge.

Vibration while accelerating.

The vehicle is in limp-in mode.

IAC faults

The compressor clutch will not engage and the cooling fans runs constantly.

Turn signals and flashers inoperative.

The climate control system display is blank.

Gauges inoperative, transmission stuck in second gear, engine starts and stalls.

A very audible fan-like noise.

VSS or TPS shorting crank/cam signals

Soft pedal after pad replacement.

Multiple steering issues.

Variable valve timing problems

Harness damage to crank sensor

Crank reluctor damage

All gauges are inoperative.

MAF sensor failures

The AC/heater controls are flashing.

Cam timing incorrect or crank reluctor damaged

Scan tool pulls “undocumented code FD”.

TPS and sub TPS connectors switched

Excessive carbon build-up

Electronic throttle control faults

Very bad bucking at highway speeds.

ABS light is on with no codes.

EGR pipe and passage carbon

ABS and brake lights are on, speedometer is inaccurate or inoperative.

Tapping noise from rear of engine with possible low power issue.

Faulty VSV for EGR

The speedometer does not show lower speeds. The ABS and brake lights may be on.

The engine will not run after replacing the BCM.

Transmission in limp-in with no communication to scanner.

The AC clutch will not engage.

The speedometer is inoperative.

The tachometer does not work.

Problem with aftermarket air filters

Dirty throttle plate

Alternator has no output and the AC clutch does not work.

After PCM replacement, the ABS light is on.

Transmission failure causing stalling

Throttle relearn procedure

Carbon build-up on intake valves

PCM update for random misfires

Ignition coil update

Updated PCM for P0773

Updated Converter/Inverter

PCM update and pipe update for P0420

Common causes of P3190, P3191, P3101

Updated Hybrid control ECU

Updated Accelerator Pedal Assembly

Faulty HCAC bypass valve

Skid control ECU update

PCM update for catalyst codes

Fuel pump failure

Restricted line at canister

EGR vacuum solenoid failures

Crank gear reluctor damaged

Coolant leaking on PCM

Timing belt alignment incorrect

ECT sensor failures

The main fusible link blows.

Excessive vibration after timing belt replacement.

The AC system is inoperative.

Timing chain jumped or reluctor damaged.

Cooling system flush causing P0128

Broken wire at crank sensor.

Downstream O2 sensor can cause lean or rich codes.

Rotor button installation

Failed igniter unit

Timing belt/cam timing incorrect

Transponder key bad or missing

Throttle stop tamper or dirty throttle body

30 Amp EGI fuse blown

Blown intake gasket

EGR ports plugged with carbon

PCM damage due to spill

Timing belt off causing cam codes

EGR boost sensor vacuum line

Crank sensor air gap

Plug boot burn through

Tank refilled with engine running

Injector connectors accidentally swapped.

Pressure regulator ruptured

Solenoid connectors swapped.

IAC valve needs cleaning

Oil pressure relief valve stuck

Crank sensor harness chaffing

ECT causing no-start when cold, or after hot soak.

Faulty EGR pressure sensor

Faulty IAC valves are common

ECM harness breakage

Coil on Plug system failures

Vacuum leak at PCV hose

PCM coil driver failure

Upper intake gaskets leaking vacuum

Oxygen sensors read 0 volts constantly.

Connectors accidentally switched

Vacuum port to boost sensor plugged

Crank sensor mounting bolt loose

Repeat distributor failure

Variable induction system

Valve covers leaking oil onto plug wires

Wires broken at purge solenoid

IMRC actuator and PCM failure

Intake gaskets

Boost sensor solenoid vacuum port

Fuel pressure regulator sticking open

PCM update for P0481

PCV hose causing lean codes and rough idle

O2 sensor identifications

O2 sensor bank identifications

Timing alignment marks can be confusing

Throttle stop adjustment or sticking IAC causing high idle.

Balancer damage causing low power.

Engine oil keeping valves open

Valvetrain problems

IMRC shaft sticking

Ignition coil causing CKP codes

Blown fuse setting multiple codes

MAF sensor causing stalling immediately upon start-up

Wrong fuel injectors

PCM reflash for Flex fuel vehicles

Balancer or keyway worn or broken

Connector under drivers seat

Relays

Canister vent solenoid failures

Excessive RFI causing P0320

ABS light on.

Power door locks try to activate.

The crank pulley bolt will not break loose.

Large oil leaking from behind timing cover.

ABS light is on and will not clear.

Speedometer indicates 20 mph when the vehicle is not moving.

Reading and clearing ABS/TCS and air bag codes without a scan tool.

Coil or Rotor faults

EGR system faults

Intake valve wear is common

Split air intake hose

Fuel pressure regulator faults

Distributor unit has failed

Base idle tamper causing P0505

Timing belt or crankshaft reluctor faults

Evaporative faults

EGR open at idle

Soda drink contamination

Alternator does not charge at startup.

Inconsistent idle after transmission flush.

Plug boots burned or carbon tracked

Mass air sensor problems

Suspension clunk.

Noise from power steering pump.

Brake pedal going to the floor, usually intermittent.

Cutting Honda non-floating rotors to fix a pulsation.

Repeated axle seal leak.

Timing belt problems causing codes

SRS light is on.

Reading and clearing ABS codes without a scan tool.

Reading and clearing ABS codes without a factory scan tool.

Recall for ignition coils

Blown intake gaskets

EGR system problems

One spark then no start

Throttle stop adjustment tamper

Coolant leak.

The ABS pump constantly runs.

One or both of the rear window motors are inoperative.

Intake problems

Properly timing the balance shaft belt.

Plug wires and coil failures

MAF contamination

Worn crankshaft thrust bearing

Crank gear keyway broken

Air Flow sensor spring tension problems

EGR boost sensor relocation

Crank sensor air gap or bracket

MAF causing rich and lean codes

EGR boost sensor hose or vacuum port

EGR ports plugged with carbon deposits

Excessive oil consumption.

EGR boost sensor and/or solenoid failure

Air intake boot split/cracked

PCM reflash for P1170

PCM update for P0507

Weak ignition coil or burned rotor

Aftermarket Cap and Rotor causing codes and rough running

Plug wires and valve cover gaskets

Water damage to PCM and connector

Timing belt jumped

Aftermarket distributor caps and rotors do not work well on this engine

Faulty MAF sensor or hotwire contamination

Air intake hose split

Cam or crank gears slipped

Vacuum leaks causing rev limit

Vacuum T’s leaking

Timing belt alignment is incorrect

Super charger using oil

Coolant in the oil.

Rear drum brake grabbing.

Crank sensor air gap too small

Poor PCM internal grounds

Air intake hose or resonator cracked

Distributor cap failures

EGR valve causing drivability issues

Aftermarket exhaust causing EGR codes

Wrong timing marks used

Subaru EGR system failures

Headlamp door motor.

No/low clutch pedal.

Mass Air Flow meter failures

The alternator will not charge.

Test connectors touching

Instrument cluster problems.

Cam belt alignment

The rear defroster does not work.

Exhaust valve guide problems

High idle codes, decel stalls, decel stumble

The brake lights do not work or do not turn off.

A/F sensor faults

Fuse loose in fuse panel

Speed sensor codes

MAF causing stalling

IAC failures

Coolant temp sensor failures

Cam and crank sensor issues

Power steering pump noise.

Side air bag light is illuminated.

Coolant in the oil system.

Cruise control inoperative.

Corrosion in harness near canister drain valve

Knock sensor failures

A/F ratio sensor causing misfire codes

Erratic spark or spark on one coil only

Reoccurring P0420

Poor grounds at body or engine

Valves too tight causing rough idle, excessive emissions

PCM failure

TPS wiring harness issues

PCM update for A/F sensor codes

Tumble valve issues

SRS light is on with no codes stored.

Wipers come on with headlights.

Blower motor operation.

Always replace the oil pump drive o-ring when replacing the intake manifold gaskets.

Bad batteries and dirty throttle plates

Carbon tracked plug wire boots

Shorted sensors

EGR valve open at idle

Knocking on cold start.

No-start, ASD relay fuse blown

PCM internal coil driver failure

Timing belt has jumped

EGR BPT failures

Upstream O2 sensor failure

Crank or Cam Sensor failure

Intermittent ASD relay failure.

Cannot communicate with the sensing diagnostic module.

AC compressor intermittently shuts off.

Timing belt 1 tooth off

The AC compressor does not engage.

The cruise control operation is erratic.

Noise from the front suspension.

Fuel pump relay voltage drop

Connector corrosion causing P1494

Turbo hose connections loose

Roll over valve leaking

Turbo hose connections

High PCM failure rate

New fuel pumps keep going bad.

Faulty fuel pump relay module

Shaking from front end.

Chirping from engine.

Timing marks not completely accurate

EGR valve and transducer

Purge flow solenoid installed upside down

Bucking when turning.

The blower motor will not turn off.

Grinding from rear differential.

Crank sensor inop

Carbon tracked ignition cables

Speedometer and tachometer are intermittently inoperative.

Shorted sensors causing no start

O2 sensors causing blown ASD relay fuse

Repeat oil leak from the rear of the engine.

The instrument cluster intermittently fails.

Camshaft gear alignment pin broken

Crank sensor signal erratic

Timing marks not perfect

Theft system activated

Coolant leak from front of engine.

Oil leak from rear of engine.

Ignition failure sensor or capacitor fault

Popping or cracking from front suspension.

MPI main relay failure

Faulty EGR control solenoid

Crankshaft reluctor damaged when replacing timing belt

Crank position sensor harness shorting

Intermittent EGR problems

Timing belt causing misfire codes

Distributor coil or igniter failures

Timing belt damaging crankshaft reluctor

Cam and/or crank sensor codes

High IAC failure rate

Fuel pump module

P0125 is an oxygen sensor fault, not ECT

Weak distributor or faulty rotor

Faulty distributor

Crank gear worn

Crank sensor reluctor wheel

Incorrect code P0100

High rate of PCM failure

Weak coil or defective rotor and cap

CKP sensor causing high RPM cut out

Faulty MDP sensor

Low detection switch

PCM reflash and O2 replacement for P0154

Vacuum control valve fault

Restrictor and vacuum supply

IAC valve damaged by throttle body cleaning

One coil not firing

Incorrect Cylinder ID

O2 sensor ID

Inspect the correct cylinder for misfires

O2 sensors failing when hot.

Knock sensor failures due to water

One side of engine misfiring.

High rate of FPR failure

Intake gasket problems

Distributor cap causing hard kickback on starting

MAF sensor causing low power and system lean codes

Fuel pump connector

Faulty aftermarket distributor caps

Ignition switch failures

Crankshaft worn

New crank sensors are faulty

P0446 faults

High rate of fuel level sensor failure

Fuel pump failure rate is very high.

Ignition control module

Communication faults

Wiring at fuel pump housing is bad

O2 sensor causing misfiring

Distributor shaft magnetized

Poor vacuum signal to MAP sensor

Corrosion inside the VCM

O2 harness shorting to ground

Exhaust valves sticking due to carbon.

Injector poppets clog after engine work

Fuel pressure regulator leaking

Gas contaminating the PCM

Distributor installed incorrectly

Distributor cap causing misfires and hard start

Faulty canister vent valve

O2 sensor failures

Fuel tank pressure sensor shorted

Intake gasket internally leaking

Broken wires to ignition coil

Air pump failure

Air check valve failures

PCM injector driver shorting.

One plugged converter

Water and rust in fuel rail

Faulty vent valve

Wiring breakage for electronic throttle control

Wiring harness rub through at left control arm

High crank sensor failure rate

Ignition coil has failed

Issues with variable valve timing

Wiring chafing under master cylinder

Crankshaft gear grooved and offset

O2 wiring shorting on AC line

High failure rate of MAF sensors

No spark, no fuel

Cam sensor codes and valve timing

Broken wires near brake booster

TPS failures

Plug wire faults

Intermittent main relay

PCM failed

High rate of IAC failure

Intermittent lighting failure.

Distributor synched improperly

Harness shorting on transmission housing

Transmission causing stalling at idle or at stops

Broken power feed to ignition coil

Poor ground in the rear cargo area.

Purge and canister solenoid valves

MAF sensor problems

P0700 description

Coolant temp sensor voltage too low.

Faulty G Sensor

Crank sensor is faulty

Faulty TPS causing high idle speed

Faulty coolant temp sensor

Intake gasket blown at cylinder #1

Plug wires switched for cylinders 1 and 4.

Faulty plug wires and ignition coils.

Faulty ignition failure sensor

MAF sensor calibration

EGR solenoid sticking

TPS glitches

Plug wires and misfires

PCM update for P0130, P0530

Transmission oil temp sender.

Poor ground causing transmission issues

Pulse generator failures are high

Faulty relay or wiring harness short

Faulty or misadjusted range switch

High idle in extremely cold climates.

PCM update for P0116

PCM update for O2 codes

Fuel pump campaign

Blown intake manifold gasket

Fuel pressure regulator diaphragm ruptured

Timing belt installation is confusing

Broken wires near vent solenoid

Cracked exhaust manifold

Ignition module recall

Faulty ignition switch

Air pump and check valve failures.

Canister purge and/or vent solenoid

EGR vacuum hose orifices

Faulty MAF sensor causing lean codes

Damaged crank sensor

CKP causing rough running

Throttle plate or IAC valve

IAC sticking open or is defective.

Distributor, coil, or igniter failure.

Crank sensor reluctor has spun

Faulty cam position sensor

Ignition switch low voltage

Converter clogged or partially clogged.

Complex timing belt installation

Dirty or bad MAF sensor

Timing belt woes

Intermittent CMP

Mass Air Sensor

Crank sensor faulty

Throttle body and wiring harness update

Main Relay update

Faulty crank sensor giving transmission codes

Codes galore

Intermittent MAF sensor faults.

Vent control valve fault

ECU injector driver shorted in ground internally

Burned rotor, weak coil

Faulty or dirty Air Flow Sensor

ECT causing surging and possible codes

Faulty connector or loose connection

False codes

High resistance at ignition failure sensor.

Leaking Fuel pressure regulator

One or two faulty crank sensor

Plug wires and oil leaks

Saturn EGR failures

Air flow meter issues

MAF sensor

High idle

Cam sensors and timing belts.

Diagnosis Module for Tank Leakage

Engine Control Relay or Main Relay.

Cracked exhaust manifold or flex pipe

Possible Cluster Fault

Ignition coil boots carbon tracked

Security Transponder Keys

Connector issues after repair work

Loose timing chain or broken guides

Valves not seating fully

Hose broken at EGR BPT valve

Coolant temp sensor out of range

High rate of relay failure

Underhood fuse panel issues

Coil and O2 sensor connectors accidentally switched

Poor MAF and computer grounds

Flexplate deflection

Cracked or loose air intake hose

Crank and/or cam sensor failure

Wrong spark plugs used

Poor PCM grounds are common on this vehicle

Air Flow sensor dirty or skewed

Timing belt jumped, broken or stripped

CKP sensor cause long crank time

TPS and transmission codes

Computer ground located under PCM

Cam timing and excessive emissions

Plug wire carbon track or burn through

TPS harness issues

Connector issues

EGR valve not fully closing

Poor MAF ground circuit

Faulty ECT readings

Timing belt alignment issues

Carbon track or oil soaked plug wires and coil boots.

Crank gear keyway rusted away

Crank sensors causing hard start, no-start

Crank sensor causing erratic behavior

EGR opening too much

Crank sensor and/or cam sensor

Erratic or unstable idle

Fuel pump cut off switch

Fuel tank pressure sensor disconnected

Carbon restricted EGR passages

Failed ignition relay

Crank sensor no-start failure

Very high rate of CMP sensor failure

Timing chain failure or incorrect installation.

Dripping injectors

Long crank time before starting

TPS or O2 voltage shorting TPS signal

Cracking vapor hoses

Low idle and stalling at stops

Neutral switch or trans range switch connector

Shorted O2 sensor causing blown fuse

Crank sensor variation learn

Injectors clicking KOEO

Crank sensor reluctor ring

P0101 faults

TPS, MAF connector problems

TPS ground circuit

Corrosion under carpet at ECU

Exhaust backpressure

EGR and passages

Connector problems

IAC passages

Connector problems behind headlight

EGR and rough idle

Cam sensor reluctor change

Cam sensor leaking at connector

Corrosion at connectors C101 and C102

Distributor and crank sensor connectors swapped.

Repeat fuel pump failure or stalling

Damaged turbine shaft O-ring

Wiring harness chaffing and breaking

Faulty IAC valve

Engine overheat enrichment after coolant flush

Failed Main ECM relay or fuel pump relay

Faulty MAF sensor

Injector harness shorted

Wiring harness for injectors

EGR ports blocked with carbon

Noise suppressor

Crankshaft keyway damaged

Main relay failure

Extended fast idle

Faulty vacuum hose causing EGR codes.

EFI harness shorted to ground

Fuel pump harness shorted.

High idle or surge at idle.

Corroded connector for fuel pump

EGR vacuum solenoid

Crank reluctor installed wrong or timing off

Fuse blown

Worn crankshaft keyway

EGR ports and vacuum hoses

Fuel pressure regulator has failed

Catalyst efficiency

Oxygen sensor heater circuits

Ford System lean codes

Ford EGR flow codes

MAF sensor codes

Coolant temp sensors and codes

TPS codes

Insufficient coolant temperature code

O2 sensor signal codes

System rich codes

Diagnosing misfires

Distributor, igniter or coil failure

Faulty camshaft position sensor

Cam sensor codes

Low voltage supply to coil

Gas tank liner deterioration

Wiring rubbing on transmission solenoid pack

Evap hose leaking or hoses cracked

Cam position and valve timing phase sensors

Transfer case control module communication errors

Very high failure rate with VW MAF sensors

No start with no spark

Vacuum line or check valve faulty

ABS controller failure

Idle adaptation

Engine speed sensor

Volkswagen coolant temp sensors

MAF sensors and P0102

Turbo hoses loose or disconnected

Air intake hose cracked, loose, leaking

Rotor button shorting

P1624 Transmission fault notification

Immobilizer system

Broken vacuum hoses are common

Throttle adaptation lost

Incorrect timing belt or distributor installation

Alarm module burned out by jump starting.

Battery causing low power and codes

MAF sensor oil contamination

No power at coil or module

Ignition switch partial failure

Blown fuse for air pump

Faulty wiring

Faulty ignition coil or power transistor

Faulty power stage and ignition coil.

MAF causing hesitation

PCV hose cracked

Ignition coil on plug misfires

Vacuum leaks common on turbo engine

Plugged fuel injectors

Cam sensors, valve timing, and timing belts

Throttle adaptation lost and no power

Moderate cam sensor failure rate

Air injection vacuum hoses broken or bad combination valve

Plugged air injection passages

Air injection Pump Relay

Coolant temp sensor and hard starts

Bad Coil causing transmission or TPS codes

Mercedes MAF sensors

OVPR Over Voltage Protection Relay

Poor power feed to ignition coils

Ignition key transmitter

Wiring harness problems

Idle control malfunction codes

Ignition Discharge Modules have a high failure rate.

Spark plugs

Throttle body fault or reset procedure required

Intermittent crank sensor issues

Intermittent purge valve faults

Strong PCV system

Vent valve vacuum leaks

Vacuum leaks at valve cover gaskets

Bad vent valve in intake manifold

Deceptively plugged EGR ports

Faulty ignition coils or boots

Manufacturer misfire codes.

Transfer case damage

BMW MAF sensors

Leaky intake gaskets

Broken vacuum hoses for secondary air injection

Plugged air injection passages in the head

Electronic thermostat

Damaged air pump due to water or condensation.

Timing chain jumped on one or both heads

Washed down cylinders

Air intake hose cracked/split

Brake switch, clock spring or throttle body

Intermittent hard stall while driving

Jag MAF sensors

Vacuum Elbow or intake leak

Intermittent Purge Valve

Very slightly blown head gasket

PCM and no starter engagement

No start after engine or flywheel swap

Cracked evap hoses near air cleaner

Flex fuel vehicles with rough/rich conditions

Cooling fan relay/module

Rich Flex fuel 3.3

Nissan MAF sensor failures

Faulty TPS/Throttle body unit

Ignition coils and spark plug wells

Locating the coil causing P1320

Sludge or solenoid causing cam codes

Swirl Control Solenoid or Switch

No-start or rough running/MIL after clutch replacement

Intermittent stall or no-start

Mercedes 3.2 EGR codes

Chrysler P0700 and P0500

Fuel pressure regulator leaking fuel into intake

Injectors causing misfire codes

Intake valve carbon build-up

Shorted MAP, TPS or EGR

Chrysler MAP sensors

Ford ESM

IAC windings shorting PCM drivers

Shorted electric motor mounts

MAF sensor causing O2 codes

O2 harness shorted on exhaust or heat shields

BMW transponder key problems.

BMW cam position sensors

Leaking intake runners or t-body gasket

Thermostat allowing flow when cold.

Intermittent stalling due to crank sensor

Oil level sensor blowing fuse causing no-crank

Water contamination in the Motronic control unit.

Poor grounding at distributor

Incorrect code number P0481 or p0181

Vacuum leak at PCV hose near throttle body.

Carbon tracked plug and coil boot

Wiring harness to ignition coils misrouted

Vacuum hose disconnected or rotting for LDP

Distributor rotor problems

BMW purge valve

False 1215 MAF code

Cam sensors causing hesitation and low power

Air injection vacuum control solenoid

Idle switch

Throttle switch malfunctions

High failure rate of Saab ignition discharge modules

Check cranking voltage

Picky with spark plugs

Faulty thermostat, stuck open

PCV hoses and intake gaskets

Transmission neutral switch

Intermittent stumble or stall at idle only

Poor grounds at engine and intake

Intermittent Saab MAF sensors

Wastegate rod siezed

Faulty ignition switch causing intermittent stall

Charge air bypass valve

Ignition discharge module causing misfires under a load

T-stat causing hard start or long crank time when cold

Saab idle quality and possible lean codes

VW cam position sensors

VW coolant temp codes

Volkswagen purge control valves

Vacuum leaks causing idle adaptation codes

Faulty O2 sensor causing fuel trim codes

Faulty fuel pump relay causing trouble codes

Fuel pressure regulator and/or vacuum hose

Bad aftermarket cam position sensor

Cam gear slipped, pin broken

Kia 2.4 crank sensors and reluctors

Kia purge flow and vent valves

EGR solenoid sticking closed

Exhaust manifold cracks causing O2 and lean codes

2.4 timing belt jumped

Using used parts

Map sensor port blockage

Hole burned through coil

P0601 internal PCM error.

Late model GM Catalytic converter problems

Re-torque intake bolts and install updated springs

BCM problems

Security relearn after battery disconnect or drain

Probable thermostat operation

Throttle body and harness malfunctions

Throttle re-learn procedure

Corroded connecter in drivers side kick panel

Vacuum leaks and un-metered air leaks

Cracked hose can cause lean or rich codes

Volvo MAF sensor failures

Faults in other modules

Volvo secondary air injection

Common cam sensor failure

ECT causing hard start or no-start

Rotor and distributor cap failures

Relay problems

Ground wire left loose or corroded at motor mount

Grounding and power supply issues

Radio suppression relay

Old style European fuses

Faulty Volvo crank sensors

Chrysler charging system control

Injectors and relays clicking key on engine off

Cooling system codes

Long cranking time before engine starts or intermittent no-start

GM 8.1 crank sensors

No power on acceleration

Faulty O2 sensor causing misfires and possible codes

Hesitation or bog that comes and goes

Poor ground connections under drivers door area

Sticking IMRC rods or poor vacuum

EGR passages behind throttle body plugged

CKP sensor signal degradation

Purge valve causing system lean codes, rough idle, excessive emissions

Security Failure

Poorly grounded

Carbon, valves and valve guides

Harness rubbing near throttle body

Distributor cap and carbon button

Distributor cap ground strap

Water in spark plug wells

Update sensor and harness for knock codes

EGR valve or backpressure tube plugged

EGR backpressure hose broken/burned

Nissan MAP/Baro solenoid

Skewed oxygen sensors

Synchronizer shaft wobble causing codes

Chrysler P0622 alternator faults

Oxygen sensor ground circuit splice

Generic Mitsubishi EGR tip

Resetting Nissan Electronic Throttle Body

Jeep PCM coil driver failure

Volvo evap components

Faulty EGR valve and Pipe

Volvo electronic throttle control

Crank sensor interference

Volvo oxygen sensor codes can be deceiving

Crank sensor or cam sensor

Nissan Knock sensor problems

Transmission and throttle angle calibration issues

Faulty TPS and updated software

PCV vacuum harness

Possible updated hose or missing switch

Out of Calibration Volvo MAF

ABS controller and wheel speed sensor

Volvo MAF causing system rich codes or rough idle.

Oxygen sensor heater circuit malfunctions.

Intermittent no-crank condition

Nissan 3.3 optical distributor

Poor O2 sensor grounding

Poor fuel injector harness connections

Converter backpressure causing random misfires and low power

Hemi IAC codes

Distributor gear worn

Two part TPS

EGR ports causing P0402 excessive EGR flow code

Fuel injector problems causing misfire on start-up

Nissan distributor shaft failure

Timing belt alignment causing P0340

Oxygen sensor failing intermittently

Chrysler evap hoses

Cruise cancel switch causing issues

Different camshaft reluctors

Intermittent IAC faults

Valve spring issues on the 3.7 Jeep

Mazda EGR boost sensor faults

Hoses at fuel tank

Ecotec ignition control module and coils

Canister vent valve not sealing

Fuel pressure drops off after a distance

Fuel Pump Driver Module connector and power feed

Wires rubbing on IMRC shafts and linkage.

Crank sensor waveform breaking down

Internal PCM fault

Intermittent cam sensor operation

Grounding problem for fuel pump and brake lamp

EGR pintle plugged with carbon deposits.

Wrong firing order printed

Vacuum leak behind intake plenum

Idle bypass screw tamper or stuck IAC motor

Tail lamp socket causing C1295

PAD lamp fault

Intake manifold and backfire valve

Faulty cam position sensor that may not code

O2 harness shorted on transfer case

Some use CCD type ignition module.

CKP, CMP or VSS shorting out Communication

Cam Phase Incorrect

False MAF code caused by air inlet tube

Faulty VMV driver in PCM

Ford intrusive O2 test

GM Linear EGR valves

Security systems

Weak permanent magnet

Converter causing EGR problems

Harness chaffing near left wiper pivot.

Ground wire corrosion or broken

Electronic AIR check valve stuck closed

Typical Air Injection failures

EOT sensor faulty

Broken valve spring common

Vibration and rough idle

O2 sensor connectors

FPDM Connector

Broken balancer and crank sensor issues

Weak battery and dirty throttle body

Harmonic balancer slipped

Starts when checking for spark

Evap Vent Solenoid causing evap leak codes

PCM causing misfire and rough/surging idle.

Multiple TPS and throttle motor codes stored

Evap leak at fuel fill neck

Intermittent fuel pump relay

EGR codes return after clearing

PCM Fuse blown

Faulty Injector Driver Module

Connector problems at valve cover.

Failed injector and/or O-rings causing no start

Stuck IPR or open circuit to IPR

Faulty cam position sensor common on powerstroke

Intermittent PCM reset

Code P1688 is very common

Plugged EBP sensor pipe

Cam sensor air gap causing drivability problems

Failed ICP causing crank-no-start.

Exhaust backpressure valve stuck closed

IPR causing harsh bucking and surging.

Glow plugs and glow plug relays

Reflash for false P0340

Using ICP and IPR for hard start

Low oil or weak primary oil pump

Misfire, rough running after repairs

Fuel line fitting seals deteriorating

Low power or loses power under higher loads

Worn engine and turbo due to poor air filtration

High oil pressure leaks

Old and thick oil causing hard starts on cold morning

Rough erratic idle caused by faulty ICP sensor or IPR

Failed IDM module and water intrusion

EGR hanging on the 6.0 Diesel

Faulty TAC can cause a hard stall and a crank-no-start.

Firing order and plug wire routing

Faulty ICP sensor

Stuck IPR causing no-start

Faulty injectors causing misfires

Faulty Idle Validation Switch

Old foaming oil causing rough idle

Intermittent high pressure oil leak

Dual mass flywheel causing idle vibration/miss and rattle noise

Sudden loss of power/throttle response

Converter breaking apart

Mixed up sensors

Crank sensor cutting causing engine to bog

Toyota A/F sensors vs oxygen sensors

Broken or jumped upper timing chain

Fuel solenoid driver module failed

Very high failure rate of ignition coils

Snap to connect fitting broken, updated bracket

TCC solenoid sticking when cold

Upstream converter broken

Updated heat shield

Line pressure solenoid ground wire

Ignition coils melted

Rear sensor causing code for front sensor

Trans solenoid sticking.

Mild backpressure causing P0410 and/or low power

Check oil level and condition

Injector windings shorted

Leaking PS pressure switch

Open or shorted windings

IAC hanging high or low

Hesitation/low power at higher RPM ranges

Noisy supercharger causing reduced timing and power

PCM update for P0103

Drivers side impact air bag connector

Fuel pump issues causing long crank and hard starting

Variable valve timing and solenoid issues

Faulty crankshaft position sensor

Purge stuck open

Throttle plate needs cleaning

Over Reporting MAF sensor

Updated valve springs and seals

Oxygen sensor not heating up quick enough

Wrong O2 sensor listed in parts catalog

Intake gaskets causing MAF codes and more

Evap leak at filler neck area

MIL on with codes P2646 and/or P2647

O2 sensors incorrectly connected

PCM update for P1275

Sticking power steering pressure switch causing high idle

Poor ECM Grounding causing U1000 or U1010

Extreme cold weather causing no-crank condition

Burr on CKP reluctor plate can cause P0335

Connector issues causing multiple symptoms

Seatbelt pre-tensioner harness

Updated valve body to address P0840 and low power concern.

Extreme cold causing P0710

Coil leaking voltage past boot connection

Liquid Vapor Separator cracked

Updated 2nd gear switch

Intermittent cam sensor failure

Subaru purge valve causing vent valve codes

Slight purge valve leak

Throttle plate causing MAP codes and more

EGR tube plugged with deposits

Hoses under intake manifold leaking vacuum

Fuel level sensor problems

High rate of ignition coil failure

Hard misfire due to carbon tracking

PCM will not relearn closed valve position

O2 sensor failing and causing misfires

Fuel injector stuck closed

Broken and corroded vent valve harness

Faulty vent valve/pump module

Volvo IAC sticking

Fuel pressure slightly high

Dual plug ignition coil

Intermittent cam sensor codes due to insulation break down

AC clutch causing blown fuse for BCM power

Trans temp sensor may break during removal

EBCM Faulty

Main power feed broken at starter

Water intrusion causing misfires

Weak ignition coil causing various driveability concerns

EGR cooler leaking coolant into intake

Broken filler neck, crack just below fuel cap.

Faulty crank sensor causing no-start or intermittent stall and codes.

Torque converter faults

Leak at upper gasket on throttle body

O2 sensor dies when hot

Wire broken at purge solenoid

Cam timing off by one tooth

Broken wire for PATS

Plug wire burned through at boot

Check valve broken

Head gasket causing repeated catalyst failure codes.

Fuel Injector Failure

TPS causing intermittent high idle condition

Injector harness shorting on studs

Harness and speed sensor problems

Spark plugs causing PCM and Coil failure

Vacuum leak at vacuum resovior

O2 sensor causing a surging or rhythmic roughness at idle

Split air intake hose causing lean codes

Rocker arms popping out

EGR pipe and/or throttle body port

Stuck PCV causing a high idle and P1506

Hard misfire caused by shorted ignition coil.

Traction control faults

Vacuum leaks causing O2 sensor codes

Hidden Vacuum Leak

FPR intermittent leak

EGR ports at rear of intake manifold

Poor ground at bell housing causing ABS code

Air inlet hose allowing water ingestion

Ignition switches and solenoids

Fuel pump failures

ASD relay driver

Breather hose cracked at intake manifold

Harness shorting on stud

No fuel pressure

PCV vacuum hose softens

O2 sensor failing intermittently causing drivability

Ambient temp sensor missing

Injector faults causing misfire codes

Ignition boot carbon tracking

Glow plug failed

PCM board causing stalling and/or no-starts

IAC valve binding and coked

Weak battery causing U codes

Fuel pump module cracked and broken.

High idle condition caused by TPS

Honda fuel injector failures

Whistle and rough idle

Multiple dead ignition coils

Crank sensor heating up

Water/Coolant in TDC connector.

Wires broken at evap vent solenoid

A/F sensor codes return after repairs

IAC shorting out drivers in PCM