OBD-II code · Powertrain (generic, extended)
P2E71 Hybrid/EV Battery Pack B Cell Thickness Sensor Circuit High
The cell thickness sensor of HV battery pack B reports voltage above the expected window. Cell-group voltage monitoring is the foundation of HV battery safety — drift here triggers contactor opening, charge inhibit, and reduced power to protect the pack.
Is it safe to drive with P2E71?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySignal wire shorted to B+
- PossibleOpen sensor
- Less likelyConnector pins corroded - high contact resistance
Symptoms
- EV/hybrid system warning light on
- Reduced power output or limp mode
- Charging may fail or be slowed
- Reduced electric range
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 4–20 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Hybrid Battery Pack B, Hybrid Battery Pack B Thickness Sensor, Bms
Related codes
- P2E6DHybrid/EV Battery Pack A Cell Thickness Sensor Circuit High
- P2E6EHybrid/EV Battery Pack A Cell Thickness Sensor Circuit Low
- P2E6FHybrid/EV Battery Pack A Cell Thickness Sensor Circuit Performance
- P2E70Hybrid/EV Battery Pack B Cell Thickness
- P2E72Hybrid/EV Battery Pack B Cell Thickness Sensor Circuit Low
- P2E73Hybrid/EV Battery Pack B Cell Thickness Sensor Circuit Performance
- P2E74Hybrid/EV Battery Pack Coolant Temperature Sensor D Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.