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.
- P1620Oldsmobile · PowertrainLow Coolant Circuit
- P1621Oldsmobile · PowertrainPCM Memory Performance
- P1622Oldsmobile · PowertrainCylinder Select
- P1623Oldsmobile · PowertrainTransmission Temp Pull-Up Resistor
- P1624Oldsmobile · PowertrainCustomer Snapshot Data Available
- P1625Oldsmobile · PowertrainPCM System Reset
- P1626Oldsmobile · PowertrainTheft Deterrent Fuel Enable Signal Lost
- P1627Oldsmobile · PowertrainA/D Performance
- P1628Oldsmobile · PowertrainECT Pull-Up Resistor
- P1629Oldsmobile · PowertrainTheft Deterrent System Cranking Signal
- P1630Oldsmobile · PowertrainTheft Deterrent Learn Mode Active
- P1631Oldsmobile · PowertrainTheft Deterrent Start Enable Signal Not Correct
- P1632Oldsmobile · PowertrainTheft Deterrent System Fuel Disabled
- P1633Oldsmobile · PowertrainIgnition Supply Power Circuit Low Voltage
- P1634Oldsmobile · PowertrainIgnition 1 Power Circuit Low Voltage
- P1635Oldsmobile · Powertrain5 Volt Reference 1 Circuit
- P1636Oldsmobile · PowertrainPCM Stack Overrun
- P1637Oldsmobile · PowertrainGenerator L-Terminal Circuit
- P1638Oldsmobile · PowertrainGenerator F-Terminal Circuit
- P1639Oldsmobile · Powertrain5 Volt Reference 2 Circuit
- P1640Oldsmobile · PowertrainDriver 1 Input High Voltage
- P1641Oldsmobile · PowertrainFC Relay 1 Control Circuit
- P1642Oldsmobile · PowertrainFC Relay 2 And 3 Control Circuit
- P1643Oldsmobile · PowertrainEngine Speed Output Circuit
- P1644Oldsmobile · PowertrainTP Output Circuit
- P1645Oldsmobile · PowertrainEVAP Solenoid Output Circuit
- P1646Oldsmobile · PowertrainDriver 1 Line 6
- P1647Oldsmobile · PowertrainDriver 1 Line 7
- P1650Oldsmobile · PowertrainDriver 2 Input High Voltage
- P1651Oldsmobile · PowertrainFan 1 Relay Control Circuit
