Index
Fault codes, decoded
Had the code read? Good — that's the right first move, and it's free at most US parts stores. Now find it below for what it actually means, what it should cost, and where shops most often get it wrong.
Misfires & engine timing
P0300Random / Multiple Cylinder Misfire DetectedP0301–P0306Cylinder-Specific Misfire Detected (Cylinders 1–6)P0016Crankshaft/Camshaft Position Correlation (Bank 1, Sensor A)P0010Camshaft Position Actuator Circuit (Bank 1)P0011Camshaft Position Timing Over-Advanced (Bank 1)P0335Crankshaft Position Sensor CircuitP0340Camshaft Position Sensor Circuit
Fuel & air mixture
P0171System Too Lean (Bank 1)P0174System Too Lean (Bank 2)P0172System Too Rich (Bank 1)P0101Mass Air Flow Sensor Range/PerformanceP0102Mass Air Flow Circuit Low InputP0113Intake Air Temperature Circuit High Input
Temperature & oxygen sensors
P0116Engine Coolant Temperature Sensor Range/PerformanceP0128Coolant Temperature Below Thermostat Regulating TemperatureP0131O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1)P0133O2 Sensor Circuit Slow Response (Bank 1, Sensor 1)P0135O2 Sensor Heater Circuit (Bank 1, Sensor 1)P0141O2 Sensor Heater Circuit (Bank 1, Sensor 2)
Emissions & EVAP
P0420Catalyst System Efficiency Below Threshold (Bank 1)P0430Catalyst System Efficiency Below Threshold (Bank 2)P0401EGR Flow InsufficientP0402EGR Flow ExcessiveP0440Evaporative Emission System MalfunctionP0442EVAP System Small Leak DetectedP0446EVAP Vent Control Circuit MalfunctionP0455EVAP System Large Leak DetectedP0456EVAP System Very Small Leak Detected
Idle & speed control
P0500Vehicle Speed Sensor MalfunctionP0505Idle Air Control System MalfunctionP0506Idle Control System RPM Lower Than ExpectedP0507Idle Control System RPM Higher Than Expected
Oil pressure & voltage
Transmission
P0700Transmission Control System Malfunction (Request Code)P0715Input/Turbine Speed Sensor CircuitP0730Incorrect Gear RatioP0740Torque Converter Clutch Circuit MalfunctionP0741Torque Converter Clutch Stuck Off / Slipping
ABS & communication
Not sure this matches your car?
Describe what it’s doing in your own words and the symptom checker gives you a safe-to-drive verdict, ranked causes with costs, and notes to take to the shop — free, no sign-up.
Advertisement