OBD-II code · Powertrain (generic)
P0B31 Hybrid/EV Battery D Voltage Low
The voltage of HV battery D is below the expected window. Cell-group depleted, deeply aged, or sense fault.
Is it safe to drive with P0B31?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyCells in group aged - capacity reduced
- PossibleDeep discharge event
- Less likelyPack cell imbalance approaching service threshold
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
- 3–16 h
- Emissions test
- Usually unaffected
- Parts involved
- Hv Battery D, Bms
Related codes
- P0B25Hybrid/EV Battery A Voltage Low
- P0B29Hybrid/EV Battery B Voltage Low
- P0B2DHybrid/EV Battery C Voltage Low
- P0B2EHybrid/EV Battery C Voltage High
- P0B2FHybrid/EV Battery D Voltage
- P0B30Hybrid/EV Battery D Voltage Unstable
- P0B32Hybrid/EV Battery D Voltage High
- P0B33High Voltage Service Disconnect Circuit
- P0B34High Voltage Service Disconnect Circuit Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.