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.
- P1127Lexus · PowertrainECTS Actuator Power Source Circuit Malfunction
- P1127Lincoln · PowertrainExhaust Not Warm Enough Downstream O2 Sensor Not Tested
- P1127Mazda · PowertrainHO2S Bank 1 Sensor 2 Heater Not On During Key On Engine Running Self Test
- P1127Mercury · PowertrainExhaust Not Warm Enough Downstream O2 Sensor Not Tested
- P1127Other · PowertrainExhaust Not Warm, Downstream O2 Sensor
- P1127Toyota · PowertrainETCS Actuator Power Source Circuit
- P1127Volkswagen · PowertrainLong Term Fuel Trim Bank 1 System Too Rich
- P1128Acura · PowertrainMAP Lower Than Expected
- P1128Ford · PowertrainUpstream Heated Oxygen Sensor Signals Reversed
- P1128Honda · PowertrainMAP Lower Than Expected
- P1128Infiniti · PowertrainMAP Lower Than Expected
- P1128Kia · PowertrainLong Term Fuel Trim Multiplicative Air System High
- P1128Lexus · PowertrainThrottle Control Motor Lock Malfunction
- P1128Lincoln · PowertrainUpstream Heated Oxygen Sensor Signals Reversed
- P1128Mazda · PowertrainHO2S Bank 1 Sensor 1 Signals Swapped In Key On Engine Running Self Test
- P1128Mercury · PowertrainUpstream Heated Oxygen Sensor Signals Reversed
- P1128Other · PowertrainUpstream Heated O2 Sensors Swapped
- P1128Toyota · PowertrainThrottle Control Motor Lock
- P1128Volkswagen · PowertrainLong Term Fuel Trim Bank 1 System Too Lean
- P1129Acura · PowertrainMAP Higher Than Expected
- P1129Ford · PowertrainDownstream Heated Oxygen Sensor Signals Reversed
- P1129Honda · PowertrainMAP Higher Than Expected
- P1129Infiniti · PowertrainMAP Higher Than Expected
- P1129Lexus · PowertrainElectronic Throttle Control System
- P1129Lincoln · PowertrainDownstream Heated Oxygen Sensor Signals Reversed
- P1129Mazda · PowertrainDownstream H02S Sensors Swapped
- P1129Mercury · PowertrainDownstream Heated Oxygen Sensor Signals Reversed
- P1129Other · PowertrainDownstream Heated O2 Sensors Swapped
- P1129Toyota · PowertrainElectric Throttle Control System
- P1129Volkswagen · PowertrainLong Term Fuel Trim Bank 2 System Too Rich
