DTC codes
Look up an OBD-II fault code: what it means on every car or on your make, 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.
- P1140GM · PowertrainHO2S Transition Time Ratio Bank 1 Sensor 2
- P1141GM · PowertrainHO2S Bank 1 Sensor 2 Average Voltage Level
- P1143GM · PowertrainHO2S Bank 1 Sensor 3 Lean Or Low Voltage
- P1144GM · PowertrainHO2S Bank 1 Sensor 3 Rich Or High Voltage
- P1145GM · PowertrainHO2S Cross Counts Bank 1 Sensor 3
- P1153GM · PowertrainHO2S Insufficient Switching
- P1154GM · PowertrainHO2S Transition Time Ratio
- P1155GM · PowertrainHO2S Lean Average Bank 2 Sensor 1
- P1156GM · PowertrainHO2S Rich Average Bank 2 Sensor 1
- P1157GM · PowertrainHO2S Bank 2 Sensor 2 Lean System Or Low Voltage
- P1158GM · PowertrainHO2S Bank 2 Sensor 2 Rich Or High Voltage
- P1159GM · PowertrainHO2S Cross Counts Bank 2 Sensor 2
- P1161GM · PowertrainHO2S Heater Power Stage Circuit Bank 2 Sensor 2
- P1163GM · PowertrainHO2S Bank 2 Sensor 3 Lean System Or Low Voltage
- P1164GM · PowertrainHO2S Bank 2 Sensor 3 Rich Or High Voltage
- P1165GM · PowertrainHO2S Cross Counts Bank 2 Sensor 2
- P1170GM · PowertrainBank To Bank Fuel Trim Offset
- P1171GM · PowertrainFuel System Lean During Acceleration
- P1185GM · PowertrainEngine Oil Temperature Circuit
- P1186GM · PowertrainEOT Circuit Performance
- P1187GM · PowertrainEOT Sensor Circuit Low Voltage
- P1188GM · PowertrainEOT Sensor Circuit High Voltage
- P1189GM · PowertrainEngine Oil Pressure Switch Circuit
- P1190GM · PowertrainEngine Vacuum Leak
- P1191GM · PowertrainIntake Air Duct Air Leak
- P1200GM · PowertrainInjector Control Circuit
- P1201GM · PowertrainAlternative Fuel Gas Mass Sensor Circuit Range Performance
- P1202GM · PowertrainAlternative Fuel Gas Mass Sensor Circuit Low Frequency
- P1203GM · PowertrainAlternative Fuel Gas Mass Sensor Circuit High Frequency
- P1211GM · PowertrainMass Air Flow Circuit Intermittent High
