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.
- U0629Generic · NetworkLost Communication With A/C Refrigerant Temperature Sensor “B”
- U062AGeneric · NetworkLost Communication With A/C Refrigerant Distribution Valve Actuator “A”
- U062BGeneric · NetworkLost Communication With A/C Refrigerant Distribution Valve Actuator “B”
- U062CGeneric · NetworkLost Communication With A/C Refrigerant Distribution Valve Actuator “C”
- U062DGeneric · NetworkLost Communication With A/C Refrigerant Distribution Valve Actuator “D”
- U062EGeneric · NetworkLost Communication With A/C Refrigerant Expansion Valve Actuator
- U062FGeneric · NetworkLost Communication With Coolant Pump C
- U0630Generic · NetworkLost Communication With Engine Coolant Temperature Sensor 4
- U0631Generic · NetworkLost Communication With Engine Coolant Temperature Sensor 5
- U0632Generic · NetworkLost Communication With Fan 1
- U0633Generic · NetworkLost Communication With Fan 2
- U0634Generic · NetworkLost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor A
- U0635Generic · NetworkLost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor B
- U0636Generic · NetworkLost Communication With Hybrid/EV Battery Pack Coolant Control Valve A
- U0637Generic · NetworkLost Communication With Hybrid/EV Battery Pack Coolant Control Valve B
- U0638Generic · NetworkLost Communication With Hybrid/EV Electronics Coolant Temperature Sensor A
- U0639Generic · NetworkLost Communication With Hybrid/EV Electronics Coolant Temperature Sensor B
- U063AGeneric · NetworkLost Communication With Hybrid/EV Electronics Coolant Temperature Sensor C
- U063BGeneric · NetworkLost Communication With Coolant Bypass Valve Actuator A
- U063CGeneric · NetworkLost Communication With Coolant Bypass Valve Actuator B
- U063DGeneric · NetworkLost Communication With Hybrid/EV Electronics Coolant Pump A
- U063EGeneric · NetworkLost Communication With Exhaust Heat Exchanger Bypass Valve Actuator A
- U063FGeneric · NetworkLost Communication With Engine Coolant Flow Control Valve Position Sensor
- U0640Generic · NetworkLost Communication With EVAP Fuel Vapor Temperature Sensor Circuit
- U0641Generic · NetworkLost Communication With EVAP System Pressure Sensor/Switch Circuit A
- U0642Generic · NetworkLost Communication With EVAP System Pressure Sensor/Switch Circuit B
- U0643Generic · NetworkLost Communication With Turbocharger/Supercharger A Temperature Sensor
- U0644Generic · NetworkLost Communication With Wastegate Position Sensor A
- U0645Generic · NetworkLost Communication With Active Air Dam Module
- U0646Generic · NetworkLost Communication With Motor Electronics Coolant Pump A