P01E3
Engine Coolant Temperature Sensor 3 Circuit
Generic electrical fault on engine coolant temperature sensor 3 (third measurement location, e.g. radiator outlet or heater core).
- 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 failedCommon
Parts involved
- ECT Sensor 3
- Sensor Wiring
P01E3 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.