P2AFD
Engine Coolant Temperature Sensor 4 Range/Performance
The engine coolant temperature 4 signal does not match plausibility checks against related signals. Sensor drift.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: easy
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
Common causes
Ordered by how often each turns out to be the cause.
- Sensor characteristic driftedCommon
- Sensor mounting displaced from reference pathPossible
- Sensor element aged beyond calibration windowLess likely
Parts involved
- Engine Coolant Temperature Sensor 4
- Wiring Harness
- ECM
P2AFD is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.