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.
- P1842Chevrolet · Powertrain1-2 Shift Solenoid Circuit Low Voltage
- P1842GM · Powertrain1 2 Shift Solenoid Circuit Low Voltage
- P1842GMC · Powertrain1 2 Shift Solenoid Circuit Low Voltage
- P1842Oldsmobile · Powertrain1-2 Shift Solenoid Circuit Low Voltage
- P1842Other · PowertrainTransmission Transfer Case Differential Lock-Up Feedback Switch Circuit Failure
- P1842Saturn · Powertrain1-2 Shift Solenoid Circuit Low Voltage
- P1842Volkswagen · PowertrainCheck DTC Memory Of Instrument Panel ECU
- P1843Buick · Powertrain1-2 Shift Solenoid Circuit High Voltage
- P1843Cadillac · Powertrain1-2 Shift Solenoid Circuit High Voltage
- P1843Chevrolet · Powertrain1-2 Shift Solenoid Circuit High Voltage
- P1843GM · Powertrain1 2 Shift Solenoid Circuit High Voltage
- P1843GMC · Powertrain1 2 Shift Solenoid Circuit High Voltage
- P1843Oldsmobile · Powertrain1-2 Shift Solenoid Circuit High Voltage
- P1843Other · PowertrainTransmission Transfer Case Differential Lock-Up Feedback Switch Open Circuit
- P1843Saturn · Powertrain1-2 Shift Solenoid Circuit High Voltage
- P1843Volkswagen · PowertrainCheck DTC Memory Of Distance Control ECU
- P1844Buick · PowertrainTorque Reduction Signal Circuit Desired By TCM
- P1844Cadillac · PowertrainTorque Reduction Signal Circuit Desired By TCM
- P1844Chevrolet · PowertrainTorque Reduction Signal Circuit Desired By TCM
- P1844GM · PowertrainTorque Reduction Signal Circuit Desired By TCM
- P1844GMC · PowertrainTorque Reduction Signal Circuit Desired By TCM
- P1844Oldsmobile · PowertrainTorque Reduction Signal Circuit Desired By TCM
- P1844Other · PowertrainTransmission Transfer Case Differential Lock-Up Feedback Switch Short Circuit To Battery
- P1844Saturn · PowertrainTorque Reduction Signal Circuit Desired By TCM
- P1844Volkswagen · PowertrainCheck DTC Memory Of Central Electronic Control ECU
- P1845Buick · PowertrainTransmission Gear Ratio Output Circuit
- P1845Cadillac · PowertrainTransmission Gear Ratio Output Circuit
- P1845Chevrolet · PowertrainTransmission Gear Ratio Output Circuit
- P1845GM · PowertrainTransmission Gear Ratio Output Circuit
- P1845GMC · PowertrainTransmission Gear Ratio Output Circuit
