DTC Trouble Codes
Look up a check-engine or warning code: what it means, symptoms, causes and how to fix.
P0128 — Coolant Thermostat (Below Regulating Temperature)
The engine is taking too long to warm up.
PowertrainmediumP0171 — System Too Lean (Bank 1)
The engine computer is adding a lot of extra fuel — too much air or too little fuel.
PowertrainhighP0300 — Random/Multiple Cylinder Misfire Detected
More than one cylinder is misfiring, at random.
PowertrainhighP0301 — Cylinder 1 Misfire Detected
Cylinder 1 is not burning fuel properly.
PowertrainhighP0335 — Crankshaft Position Sensor "A" Circuit
The computer is not getting a good signal from the crankshaft sensor.
PowertrainmediumP0420 — Catalyst System Efficiency Below Threshold (Bank 1)
The oxygen sensor after the catalytic converter reads almost the same as the one before it, so the converter is not cleaning the smoke well.
PowertrainlowP0442 — EVAP System Small Leak Detected
The fuel vapour system has a small leak.
PowertrainlowP0455 — EVAP System Large Leak Detected
The fuel vapour system has a big leak or is open to air.
PowertrainlowP0460 — Fuel Level Sensor "A" Circuit
The fuel level signal is not what the computer expects.
PowertrainlowP0462 — Fuel Level Sensor "A" Circuit Low
Fuel level signal voltage is too low — usually the wire is touching ground (short).
PowertrainlowP0463 — Fuel Level Sensor "A" Circuit High
Fuel level signal voltage is too high — usually a broken wire (open circuit).
PowertrainmediumP0500 — Vehicle Speed Sensor "A"
The computer is not getting a correct speed signal.
PowertrainhighP0520 — Engine Oil Pressure Sensor/Switch Circuit
The oil pressure switch / sensor signal is wrong.
PowertrainmediumP0562 — System Voltage Low
The computer sees battery / charging voltage below normal.
PowertrainhighP0563 — System Voltage High
The computer sees charging voltage above normal (usually over about 15–16 V).
PowertrainmediumP0615 — Starter Relay Circuit
The computer found a problem in the starter relay control circuit.
PowertrainmediumP0616 — Starter Relay Circuit Low
The starter relay control signal is too low — often an open or grounded wire.
PowertrainmediumP0617 — Starter Relay Circuit High
The starter relay signal is high when it should be off — the starter may keep running.
PowertrainmediumP0620 — Generator (Alternator) Control Circuit
The engine computer has a problem with the wire it uses to control the alternator.
NetworkhighU0001 — High Speed CAN Communication Bus
A module found a problem on the high-speed CAN data wires.
NetworkhighU0073 — Control Module Communication Bus "A" Off
A module stopped talking because the data bus is shut down or faulty.
NetworkhighU0100 — Lost Communication With ECM/PCM "A"
Other computers can no longer hear the engine computer (ECM).
NetworkmediumU0121 — Lost Communication With ABS Control Module
The ABS computer stopped sending messages on the data wires.
NetworkmediumU0140 — Lost Communication With Body Control Module
The body computer (lights, locks, wipers, chimes) is not talking on the data wires.
NetworkmediumU0155 — Lost Communication With Instrument Panel Cluster
Another computer in the car stopped getting messages from the meter. The meter has no power, no ground, or is not connected to the data wires.