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
P0300
Powertrain
The engine computer sees misfires that jump between cylinders or hit several cylinders at once.
High
P0420
Powertrain
The bank 1 catalytic converter no longer stores enough oxygen to clean the exhaust properly.
Low
P0430
Powertrain
The bank 2 converter on a V6, V8 or split-exhaust engine isn't cleaning the exhaust well enough.
Low
P0101
Powertrain
The MAF sensor's airflow reading doesn't match what the engine computer expects…
Low
All codes (331)
C1130
Nissan · Chassis
The ABS/VDC unit isn't getting a valid engine signal from the ECM, so it switches stability…
Moderate
C1611
Hyundai · Chassis
The ABS/ESC module stopped hearing from the engine computer on the CAN bus and shut off…
Moderate
P0001
Powertrain
The PCM can't drive the solenoid that meters fuel into the high-pressure pump. Often a no-start…
High
P0008
Powertrain
Camshaft timing on bank 1 has drifted from the crankshaft. Often a stretched timing chain.
Moderate
P0011
Powertrain
The bank 1 intake cam sits further advanced than the PCM asked for, usually an oil or control…
Moderate
P0012
Powertrain
The bank 1 intake cam lags behind the angle the PCM wants, often from chain stretch or weak oil…
Moderate
P0014
Powertrain
The bank 1 exhaust cam won't follow its target and stays too far advanced; think oil, valve…
Moderate
P0015
Powertrain
The bank 1 exhaust cam sits later than commanded; a stretched chain or stuck exhaust phaser…
Moderate
P0016
Powertrain
The bank 1 intake cam and the crankshaft are out of step, most often from a stretched or jumped…
High
P0017
Powertrain
The bank 1 exhaust cam signal doesn't line up with the crankshaft; think chain, exhaust phaser…
Moderate
P0018
Powertrain
The bank 2 intake cam is out of step with the crankshaft on a V or boxer engine; chain wear…
High
P0019
Powertrain
The bank 2 exhaust cam signal doesn't match the crankshaft; chain, bank 2 exhaust phaser…
Moderate
P0021
Powertrain
The bank 2 intake cam is more advanced than commanded or slow to respond; compare it with bank…
Moderate
P0022
Powertrain
The bank 2 intake cam can't advance as far as the PCM asks; phaser, oil pressure or a worn bank…
Moderate
P0024
Powertrain
The bank 2 exhaust cam stays too far advanced or reacts too slowly; check the valve, the oil…
Moderate
P0045
Powertrain
The engine computer sees an open or shorted circuit to the solenoid that controls turbo boost.
Moderate
P0046
Powertrain
The boost control solenoid circuit is intact, but boost doesn't follow what the solenoid…
Moderate
P0068
Powertrain
The airflow the engine measures doesn't match what the throttle opening says it should be.
Moderate
P0087
Powertrain
Measured fuel pressure has dropped well below what the engine computer is asking for.
High
P0088
Powertrain
Rail pressure is running well above the value the engine computer is commanding.
Moderate
P0089
Powertrain
The fuel pressure regulator is getting its commands but pressure isn't responding the way it…
Moderate
P0090
Powertrain
The engine computer sees an electrical fault in the wiring or coil of the fuel pressure control…
Moderate
P0093
Powertrain
Rail pressure is dropping faster than injection explains: fuel may be escaping. Stop and check…
Critical
P0102
Powertrain
The MAF signal is too weak for the PCM to accept, so it treats the circuit as dead…
Moderate
P0105
Powertrain
The PCM lost a usable signal from the manifold pressure sensor: dropouts, noise or values it…
Moderate
P0107
Powertrain
The MAP signal has fallen to almost zero volts, usually from a lost 5-volt reference or an open…
Moderate
P0108
Powertrain
The MAP signal is pinned near 5 volts, so the PCM sees impossibly high manifold pressure even…
Moderate
P0120
Powertrain
The throttle position signal dropped out or glitched, so the PCM no longer trusts the throttle…
Moderate
P0121
Powertrain
The throttle position reading is electrically valid but doesn't agree with engine load, airflow…
Moderate
P0122
Powertrain
The throttle position signal fell to nearly 0 volts, lower than a closed throttle could ever…
Moderate