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.
- P1638BMW · PowertrainThrottle Valve Position Control Throttle Stuck Temporarily
- P1638Buick · PowertrainGenerator F-Terminal Circuit
- P1638Cadillac · PowertrainGenerator F-Terminal Circuit
- P1638Chevrolet · PowertrainGenerator F-Terminal Circuit
- P1638GM · PowertrainGenerator F-Terminal Circuit
- P1638GMC · PowertrainGenerator F-Terminal Circuit
- P1638Jaguar · PowertrainCAN Link ECM INSTM Circuit Network
- P1638Oldsmobile · PowertrainGenerator F-Terminal Circuit
- P1638Other · PowertrainCan Link ECM/INSTM Circuit / Network Malfunction
- P1638Saturn · PowertrainGenerator F-Terminal Circuit
- P1638Volkswagen · PowertrainData Bus Powertrain Missing Message From Clutch Control
- P1639BMW · PowertrainThrottle Valve Position Control Throttle Stuck Permanently
- P1639Buick · Powertrain5 Volt Reference 2 Circuit
- P1639Cadillac · Powertrain5 Volt Reference 2 Circuit
- P1639Chevrolet · Powertrain5 Volt Reference 2 Circuit
- P1639Ford · PowertrainVehicle ID Block Corrupted or Not Programmed
- P1639GM · Powertrain5 Volt Reference 2 Circuit
- P1639GMC · Powertrain5 Volt Reference 2 Circuit
- P1639Lincoln · PowertrainVehicle ID Block Corrupted or Not Programmed
- P1639Mercury · PowertrainVehicle ID Block Corrupted or Not Programmed
- P1639Oldsmobile · Powertrain5 Volt Reference 2 Circuit
- P1639Other · PowertrainVehicle ID Block Corrupted or Not Programmed
- P1639Saturn · Powertrain5 Volt Reference 2 Circuit
- P1639Volkswagen · PowertrainAccelerator Pedal Position Sensor 1/2 Range Performance
- P1640BMW · PowertrainInternal Control Module ROM RAM Error
- P1640Buick · PowertrainDriver 1 Input High Voltage
- P1640Cadillac · PowertrainDriver 1 Input High Voltage
- P1640Chevrolet · PowertrainDriver 1 Input High Voltage
- P1640Ford · PowertrainPowertrain DTCs Available in Another Module
- P1640GM · PowertrainDriver 1 Input High Voltage
