P2185
Engine Coolant Temperature Sensor 2 Circuit High
The second coolant temperature sensor (often radiator-outlet or cylinder-head bank) reports a voltage above the upper threshold — typically an open signal wire or a sensor with infinite resistance.
- 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 element openCommon
- Signal wire openPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Coolant Temperature Sensor 2
- Sensor Wiring
P2185 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.