Powertrain fault codes
14821 Powertrain OBD-II fault codes: what each one means, and how to track it down.
How to read a code
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 4
- AreaAuxiliary emission controls
- 20
- FaultThe specific fault in that area
Read the code
Note every stored and pending code your scanner shows, such as P0420.
Find it
Search by code or by words. For a manufacturer code (P1, B1, C1, U1) pick your make: its meaning differs by make.
Open the code
Its page explains the symptoms, likely causes, the checks to run and the fixes.
- P015EGeneric · PowertrainExcessive Time to Enter Closed Loop Fuel Timing Control
- P015FGeneric · PowertrainExcessive Time to Enter Closed Loop Cylinder Balance Control
- P0160Generic · PowertrainO2 Sensor Circuit No Activity Detected Bank 2 Sensor 2
- P0161Generic · PowertrainO2 Sensor Heater Circuit Bank 2 Sensor 2
- P0162Generic · PowertrainO2 Sensor Circuit Bank 2 Sensor 3
- P0163Generic · PowertrainO2 Sensor Circuit Low Voltage Bank 2 Sensor 3
- P0164Generic · PowertrainO2 Sensor Circuit High Voltage Bank 2 Sensor 3
- P0165Generic · PowertrainO2 Sensor Circuit Slow Response Bank 2 Sensor 3
- P0166Generic · PowertrainO2 Sensor Circuit No Activity Detected Bank 2 Sensor 3
- P0167Generic · PowertrainO2 Sensor Heater Circuit Bank 2 Sensor 3
- P0168Generic · PowertrainFuel Temperature Too High
- P0169Generic · PowertrainIncorrect Fuel Composition
- P016AGeneric · PowertrainExcessive Time To Enter Closed Loop Air/Fuel Ratio Control
- P016BGeneric · PowertrainClosed Loop Air/Fuel Ratio Control At Limit - System Too Rich
- P016CGeneric · PowertrainClosed Loop Air/Fuel Ratio Control At Limit - System Too Lean
- P016DGeneric · PowertrainExcessive Time To Enter Closed Loop Fuel Pressure Control
- P016EGeneric · PowertrainClosed Loop Fuel Pressure Control At Limit - Pressure Too High
- P016FGeneric · PowertrainClosed Loop Fuel Pressure Control At Limit - Pressure Too Low
- P0170Generic · PowertrainFuel Trim Bank 1
- P0171Generic · PowertrainSystem Too Lean Bank 1
- P0171Audi · PowertrainControl module software needs to be updated, Vacuum leaks (intake manifold gaskets, vacuum hoses, PCV hoses, etc.), Mass air flow sensor, Plugged fuel filter or weak fuel pump, Plugged or dirty fuel injectors
- P0171Buick · PowertrainSystem Lean Bank 1
- P0172Generic · PowertrainSystem Too Rich Bank 1
- P0173Generic · PowertrainFuel Trim Bank 2
- P0174Generic · PowertrainSystem Too Lean Bank 2
- P0174Audi · PowertrainPCM software needs to be updated, Vacuum leaks (Intake Manifold Gaskets, vacuum hoses, PCV hoses, etc.), Faulty Mass Airflow (MAF) Sensor, Plugged Fuel Filter or weak Fuel Pump, Plugged or dirty Fuel Injectors
- P0175Generic · PowertrainSystem Too Rich Bank 2
- P0176Generic · PowertrainFuel Composition Sensor Circuit
- P0177Generic · PowertrainFuel Composition Sensor Circuit Range/Performance
- P0178Generic · PowertrainFuel Composition Sensor Circuit Low