Powertrain Codes (P-Codes): Full List
Powertrain codes start with P and cover the engine, fuel and ignition systems, emission controls and the transmission. They are the codes that most often turn on the check engine light and the ones most relevant to a smog check or emissions test. The third character narrows it down: 1–2 fuel and air metering, 3 ignition and misfire, 4 emission controls, 5 speed and idle, 6 computer and outputs, 7–9 transmission, A hybrid.
539Codes
2.7Average severity
12%High or critical
20%DIY-friendly
Severity distribution
Most viewed
P0135
Powertrain
The heater inside the upstream oxygen sensor on bank 1 isn't working or its circuit is faulty.
Low
P0174
Powertrain
The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction…
Moderate
P0113
Powertrain
The intake air temperature signal is stuck at maximum voltage, which usually means an open…
Low
P0171
Powertrain
The engine computer is adding the maximum extra fuel it's allowed on bank 1 and still sees…
Moderate
P0172
Powertrain
The engine computer is pulling as much fuel as it's allowed on bank 1 and the mixture is still…
Moderate
P0299
Powertrain
The turbo or supercharger isn't building the boost pressure the engine computer is asking for.
Moderate
All codes (318)
P0344
Powertrain
The bank 1 cam sensor signal keeps dropping out for short moments, which can cause random…
Moderate
P0345
Powertrain
The cam sensor on bank 2, the side without cylinder 1, has a missing or faulty signal on a V6…
Moderate
P0346
Powertrain
Bank 2's cam signal arrives out of position. On V6/V8s that often means a bank 2 chain, guide…
Moderate
P0350
Powertrain
The shared coil feed, ignition module or coil wiring is faulty. Often set with several…
Moderate
P0351
Powertrain
The engine computer found an electrical fault in coil A, the coil that fires cylinder 1 on most…
Moderate
P0352
Powertrain
Coil B, normally on cylinder 2, has a circuit fault. Where cylinder 2 sits depends…
Moderate
P0353
Powertrain
The circuit for coil C, which fires cylinder 3, failed its electrical check. Wiring is a big…
Moderate
P0354
Powertrain
Coil D, normally the one on cylinder 4, failed its circuit check. It often shows up right after…
Moderate
P0355
Powertrain
Coil E, the coil for cylinder 5, has an electrical fault. Only engines with five or more…
Moderate
P0356
Powertrain
The coil F circuit for cylinder 6 failed its check. On inline sixes it's the coil…
Moderate
P0357
Powertrain
Coil G, which fires cylinder 7 on V8s, has an electrical fault. On GM trucks it sits by…
Moderate
P0358
Powertrain
Coil H, for cylinder 8, has an electrical fault. On nearly every V8 it's the hardest coil…
Moderate
P0366
Powertrain
Bank 1 exhaust cam signal is out of position: chain stretch, a sticky exhaust phaser…
Moderate
P0402
Powertrain
More exhaust is being recirculated than the ECU asked for, usually because the EGR valve won't…
Moderate
P0471
Powertrain
The exhaust backpressure reading doesn't match what the computer expects; the sensor tube…
Moderate
P0472
Powertrain
Exhaust backpressure sensor signal near zero volts: dead sensor, grounded wire or lost 5 V…
Moderate
P0480
Powertrain
Fault in the circuit that switches the main radiator fan – the engine can overheat in traffic.
Moderate
P0500
Powertrain
The engine computer lost its vehicle speed signal – speedometer, shifting and cruise control…
Moderate
P0504
Powertrain
The two contacts in the brake pedal switch disagree on whether you're braking; check the pedal…
Moderate
P0520
Powertrain
The engine computer gets a signal from the oil pressure sensor or switch that makes no…
Moderate
P0521
Powertrain
The oil pressure reading doesn't fit engine speed and temperature – a drifting sensor or truly…
High
P0522
Powertrain
The oil pressure signal is below what a working sensor can produce – usually wiring…
Moderate
P0524
Powertrain
Measured oil pressure fell below the safe minimum. Stop the engine now and check the oil before…
Critical
P052E
Powertrain
The crankcase ventilation regulator isn't controlling crankcase pressure properly – often…
Moderate
P0560
Powertrain
The engine computer saw its supply voltage missing or out of range – check fuses and feeds…
Moderate
P0562
Powertrain
The engine computer sees too little supply voltage – usually a charging, battery or ground…
Moderate
P0563
Powertrain
The engine computer sees too much supply voltage – usually an overcharging alternator cooking…
Moderate
P0572
Powertrain
The PCM never sees the brake pedal pressed – brake lights may be out and the car may not shift…
Moderate
P0573
Powertrain
The PCM thinks the brake pedal is always pressed – brake lights stay on, often from a missing…
Moderate
P0600
Powertrain
The engine computer lost a dedicated data link to another module, most often the transmission…
Moderate