P2E77
Hybrid/EV Battery Pack Coolant Temperature Sensor D Circuit High
The ECM detects a circuit high fault on the hybrid/ev battery pack coolant temperature sensor d circuit. Reading cannot be used reliably for control.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
Common causes
Ordered by how often each turns out to be the cause.
- Signal wire shorted to B+Common
- Open sensorPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Hybrid Battery Coolant Temp Sensor D
- Wiring Harness
- Bms
P2E77 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.