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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 distributionSeverity distribution

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All codes (539)

P2200 Powertrain The engine computer lost a usable signal from the NOx sensor ahead of the SCR catalyst on bank… Moderate P2201 Powertrain The upstream NOx sensor still communicates, but its readings don't match what the ECM expects. Moderate P2202 Powertrain The upstream NOx sensor reports a signal or internal circuit below its lower limit. Moderate P2203 Powertrain The upstream NOx sensor reports a value or circuit stuck above its upper limit. Moderate P2204 Powertrain The upstream NOx sensor signal keeps dropping out or jumping around for short moments. Low P2209 Powertrain The heater in the upstream NOx sensor can't reach or hold its working temperature properly. Low P2226 Powertrain The engine computer can't get a valid reading from its barometric (ambient air pressure) sensor. Low P2227 Powertrain The baro sensor's reading doesn't agree with the other pressure sensors or with what the engine… Low P2228 Powertrain The baro sensor signal is below its valid range, as if the car were far higher than any road… Moderate P2237 Powertrain The wire that carries the pump current of the upstream wideband (air-fuel) sensor is open. Low P2238 Powertrain The pump-current wire of the upstream air-fuel sensor is being pulled low, usually by a short… Low P2243 Powertrain The ECM lost the reference-cell signal of the upstream wideband sensor, as if the wire were… Low P2262 Powertrain The engine computer commanded boost but saw almost none, pointing to a mechanical turbo… Moderate P2263 Powertrain Boost isn't tracking its target closely enough: too low, too high or too slow to respond. Moderate P2270 Powertrain The oxygen sensor after the catalytic converter won't show rich, even when the PCM deliberately… Low P2271 Powertrain The sensor after the converter stays rich even while coasting with the fuel cut off, when it… Low P2279 Powertrain Air is getting into the engine after the mass airflow sensor, so the computer isn't measuring… Low P2293 Powertrain The second fuel pressure control stage can't hold its target; on VW/Audi 2.0T often… Moderate P229F Powertrain The NOx sensor after the SCR catalyst is sending believable-looking but wrong or sluggish… Moderate P2400 Powertrain The engine computer can't drive the EVAP leak detection pump – usually a broken wire, bad plug… Low P2401 Powertrain The leak detection pump's control wire reads too low – most often a wire rubbing through… Low P2401 Toyota · Powertrain In Toyota's key-off EVAP test, the canister module's leak detection pump didn't pull… Low P2402 Powertrain The leak pump's control line reads too high – usually a short to a 12-volt wire… Low P2404 Powertrain The switch that reports the leak pump's position isn't changing state the way it should during… Low P2419 Powertrain Too little voltage on the EVAP switching (vent) valve control wire – wiring or canister pump… Low P2420 Powertrain The switching valve in the EVAP canister pump module can't be switched – its control line stays… Low P2422 Powertrain The EVAP vent path is blocked, so the tank can't breathe – slow refueling and a whoosh when… Low P242F Powertrain The DPF is filling up with ash that regeneration can't burn off; it needs cleaning… Moderate P2440 Powertrain The valve that should seal the air pump off from the bank 1 exhaust stays open, letting hot… Moderate P2441 Powertrain The air pump runs after a cold start, but the bank 1 valve won't open – no fresh air reaches… Low

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