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.
- P1039Mercury · PowertrainVehicle Speed Signal Missing or Improper
- P1051Ford · PowertrainBrake Switch Signal Missing or Improper
- P1051Lincoln · PowertrainBrake Switch Signal Missing or Improper
- P1051Mercury · PowertrainBrake Switch Signal Missing or Improper
- P1083BMW · PowertrainFuel Control Mixture Lean Bank 1 Sensor 1
- P1084BMW · PowertrainFuel Control Mixture Rich Bank 1 Sensor 1
- P1085BMW · PowertrainFuel Control Mixture Lean Bank 2 Sensor 1
- P1086BMW · PowertrainFuel Control Mixture Rich Bank 2 Sensor 1
- P1086Subaru · PowertrainTumble Generator Valve #2 LH Position Sensor Circuit Low Input
- P1087BMW · PowertrainO2 Sensor Circuit Slow Response in Lean Control Range Bank 1 Sensor 1
- P1087Subaru · PowertrainTumble Generator Valve #2 LH Position Sensor Circuit High Input
- P1088BMW · PowertrainO2 Sensor Circuit Slow Response in Rich Control Range Bank 1 Sensor 1
- P1088Subaru · PowertrainTumble Generator Valve #1 RH Position Sensor Circuit Low Input
- P1089BMW · PowertrainO2 Sensor Circuit Slow Response in Lean Control Range Bank 1 Sensor 2
- P1089Subaru · PowertrainTumble Generator Valve #1 RH Position Sensor Circuit High Input
- P1090BMW · PowertrainPre-Catalyst Fuel Trim Too Lean Bank 1
- P1090Subaru · PowertrainTumble Generator Valve #1 RH Malfunction Stuck Open
- P1091BMW · PowertrainPre-Catalyst Fuel Trim Too Rich Bank 1
- P1091Subaru · PowertrainTumble Generator Valve #1 RH Malfunction Stuck Close
- P1092BMW · PowertrainPre-Catalyst Fuel Trim Too Lean Bank 2
- P1092Subaru · PowertrainTumble Generator Valve #2 LH Malfunction Stuck Open
- P1093BMW · PowertrainPre-Catalyst Fuel Trim Too Rich Bank 2
- P1093Subaru · PowertrainTumble Generator Valve #2 LH Malfunction Stuck Close
- P1094BMW · PowertrainO2 Sensor Circuit Slow Response in Rich Control Range Bank 2 Sensor 1
- P1094Subaru · PowertrainTumble Generator Valve Circuit #1 Open Circuit
- P1095BMW · PowertrainO2 Sensor Circuit Slow Switching From Lean to Rich Bank 1 Sensor 1
- P1095Subaru · PowertrainTumble Generator Valve Circuit #1 Over Current
- P1096BMW · PowertrainO2 Sensor Circuit Slow Switching From Lean to Rich Bank 2 Sensor 1
- P1096Subaru · PowertrainTumble Generator Valve Circuit #2 Open Circuit
- P1097BMW · PowertrainO2 Sensor Circuit Slow Response After Coast Down Fuel Cut-off Bank 1 Sensor 2
