OBD-II code · Powertrain (generic, extended)
P2AFF Engine Coolant Temperature Sensor 4 Circuit High
Voltage on the engine coolant temperature 4 sensor signal line is above the expected window. Wire shorted to B+ or sensor open.
Is it safe to drive with P2AFF?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal wire shorted to B+
- PossibleOpen sensor
- Less likelyConnector pins corroded - high contact resistance
Symptoms
- Check engine light on
- Cooling fan runs constantly or not at all
- Cabin heater weak or excessively hot
- Possible long warm-up time or hard cold start
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–1.5 h
- Emissions test
- Likely to fail
- Parts involved
- Engine Coolant Temperature Sensor 4, Wiring Harness, Ecm
Related codes
- P01E6Engine Coolant Temperature Sensor 3 Circuit High
- P2185Engine Coolant Temperature Sensor 2 Circuit High
- P2B2EEngine Coolant Temperature Sensor 5 Circuit High
- P2BB9Engine Coolant Temperature Sensor 6 Circuit High
- P2AFCEngine Coolant Temperature Sensor 4 Circuit
- P2AFDEngine Coolant Temperature Sensor 4 Range/Performance
- P2AFEEngine Coolant Temperature Sensor 4 Circuit Low
- P2B00Cylinder 1 Injection Pulse Performance
- P2B01Cylinder 2 Injection Pulse Performance
- P2B02Cylinder 3 Injection Pulse Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.