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.
- P1791Cadillac · PowertrainTransmission Control Module Loop
- P1791Chevrolet · PowertrainTransmission Control Module Loop
- P1791GM · PowertrainTransmission Control Module Loop
- P1791GMC · PowertrainTransmission Control Module Loop
- P1791Honda · PowertrainTCM A/T Vehicle Speed Sensor Circuit Fault
- P1791Infiniti · PowertrainTCM A/T Vehicle Speed Sensor Circuit Fault
- P1791Jaguar · PowertrainIgnition Supply Malfunction
- P1791Mazda · PowertrainTP Electric Circuit
- P1791Mitsubishi · PowertrainPCM ECT Level Signal To TCM Circuit Fault
- P1791Nissan · PowertrainTP Electric Circuit
- P1791Oldsmobile · PowertrainTransmission Control Module Loop
- P1791Other · PowertrainTP (Electric) Circuit Malfunction
- P1791Saturn · PowertrainTransmission Control Module Loop
- P1791Volkswagen · PowertrainTransmission Range Display Circuit Short To Ground
- P1792Buick · PowertrainTransmission Control Module Reprogrammable Memory
- P1792Cadillac · PowertrainTransmission Control Module Reprogrammable Memory
- P1792Chevrolet · PowertrainTransmission Control Module Reprogrammable Memory
- P1792GM · PowertrainTransmission Control Module Reprogrammable Memory
- P1792GMC · PowertrainTransmission Control Module Reprogrammable Memory
- P1792Jaguar · PowertrainIgnition Supply Malfunction
- P1792Mazda · PowertrainBarometer Pressure Circuit
- P1792Nissan · PowertrainBarometer Pressure Circuit
- P1792Oldsmobile · PowertrainTransmission Control Module Reprogrammable Memory
- P1792Other · PowertrainBarometer Pressure Circuit Malfunction
- P1792Saturn · PowertrainTransmission Control Module Reprogrammable Memory
- P1792Volkswagen · PowertrainTransmission Range Display Circuit Short To B+
- P1793Acura · PowertrainAutomatic Transmission System Malfunction
- P1793Buick · PowertrainTransmission control Module Stack Overrun
- P1793Cadillac · PowertrainTransmission Control Module Stack Overrun
- P1793Chevrolet · PowertrainTransmission Control Module Stack Overrun
