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

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P0302 Powertrain Cylinder 2 keeps misfiring. On inline engines it's a middle cylinder, so rule out coolant… Moderate P0174 Powertrain The cylinder bank without cylinder 1 is running lean even with the maximum fuel correction… Moderate P0011 Powertrain The bank 1 intake cam sits further advanced than the PCM asked for, usually an oil or control… Moderate P0218 Powertrain The transmission fluid got hotter than the computer allows, from heavy load, low fluid… High P0301 Powertrain Cylinder 1 is repeatedly failing to fire. The cause is almost always its coil, plug, injector… Moderate P0014 Powertrain The bank 1 exhaust cam won't follow its target and stays too far advanced; think oil, valve… Moderate

All codes (331)

All Severity 3+ Severity 4+

U1000 Nissan · Network A Nissan control module couldn't send or receive CAN messages for about 2 seconds or longer. Moderate

Symptoms

Loss of power 214 Rough idle 184 Limp mode 165 Poor fuel economy 146 Engine stalling 133 Car won't start 123 Harsh or slipping shifts 80 ABS / traction light on 65 Fuel smell 34 Check engine light flashing 22