Check engine light on: Codes, Causes & Fixes
A steady check engine light means the engine computer has stored a fault that affects emissions or engine management. In most cases you can keep driving normally for now, but have the code read soon – many auto parts stores and any OBD-II scanner can do this. If the light came on right after refueling, check that the gas cap is tight; loose caps are a classic trigger for EVAP codes.
558Codes
2.7Average severity
12%High or critical
18%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 (331)
P1340
Volkswagen · Powertrain
The cam signal no longer lines up with the crank signal – often a jumped belt or stretched…
High
P1345
Chevrolet · Powertrain
The cam signal is out of step with the crank signal; on Vortec engines usually a mis-set…
Moderate
P1346
Toyota · Powertrain
Toyota's ECM sees the intake cam signal in the wrong place relative to the crankshaft signal.
Moderate
P1349
Toyota · Powertrain
Toyota's VVT-i system isn't moving the intake camshaft to the position the ECM is asking for.
Moderate
P1354
Toyota · Powertrain
On a Toyota V6 or V8, the bank 2 intake camshaft isn't reaching the timing the ECM commands.
Moderate
P1361
Honda · Powertrain
The top dead center (TDC) sensor signal keeps dropping out for a moment while the engine…
Moderate
P1362
Honda · Powertrain
The PCM gets no signal at all from the top dead center (TDC) sensor; stalling or a no-start…
High
P1380
Chevrolet · Powertrain
A misfire was detected, and the ABS module couldn't supply rough-road data to confirm it wasn't…
Moderate
P1381
Chevrolet · Powertrain
A misfire was detected while the PCM had lost contact with the ABS module that supplies…
Moderate
P1391
Jeep · Powertrain
The PCM keeps briefly losing the cam or crank position signal, which can make your Jeep stumble…
Moderate
P1399
Honda · Powertrain
An older Honda's PCM counted misfires that jump between cylinders instead of staying in one.
Moderate
P1516
Chevrolet · Powertrain
The electronic throttle didn't move to where the computer commanded, so the engine drops into…
Moderate
P1519
Honda · Powertrain
The PCM found a fault in the idle air control valve (IACV) circuit on a Honda with a cable…
Moderate
P1529
Kia · Powertrain
Your Kia's transmission computer found a fault and asked the engine computer to light the check…
Moderate
P1603
Toyota · Powertrain
Toyota's ECM logged that the engine stopped by itself while running, without the key being…
Moderate
P1604
Toyota · Powertrain
Toyota's ECM recorded a start that took too long, failed, or died within seconds of firing.
Moderate
P1607
Honda · Powertrain
The Honda engine computer's self-test found a fault inside its own circuitry.
Moderate
P1682
Chevrolet · Powertrain
The engine computer's two ignition power feeds disagree, which can cause stalling or Reduced…
High
P1698
Jeep · Powertrain
The engine computer stopped hearing from the transmission computer, often leaving the Jeep…
Moderate
P1702
Ford · Powertrain
Ford's gear selector position signal drops out now and then, so the PCM briefly loses track…
Moderate
P1778
Nissan · Powertrain
The Jatco CVT's step motor is being commanded, but the pulley ratio isn't following it as it…
High
P17F0
Nissan · Powertrain
The TCM detected judder it blames on the CVT itself, usually belt or pulley slip inside…
High
P17F1
Nissan · Powertrain
The TCM caught a judder event it links to the CVT's control valve (valve body), not yet to belt…
Moderate
P1E00
Chevrolet · Powertrain
Volt/Bolt pointer code: the hybrid/EV controller found a fault and asked for the check engine…
Moderate
P2002
Powertrain
The ECU thinks the diesel particulate filter isn't trapping soot properly — or it can't measure…
Moderate
P2006
Powertrain
The intake swirl or runner flaps stay shut when the ECU wants them open, choking airflow…
Moderate
P204F
Powertrain
The DEF/SCR system isn't cutting NOx the way it should; ignored, it leads to a severe speed…
Moderate
P207F
Powertrain
The ECM thinks the DEF in the tank is too weak or contaminated, often right after a refill.
Moderate
P20E8
Powertrain
The DEF pump can't build or hold enough pressure; suspect a leak, frozen line, clogged filter…
Moderate
P20EE
Powertrain
The SCR catalyst isn't removing enough NOx; DEF quality, dosing, a NOx sensor or the catalyst…
Moderate