OBD-II code · Powertrain (generic)
P0BA9 Hybrid/EV Battery Voltage Sense W Circuit
The BMS detects a circuit fault on voltage sense channel W of the high-voltage battery. Cell-group voltage measurement is unreliable on this channel.
Is it safe to drive with P0BA9?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySense circuit failed
- PossibleWiring fault
- 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
- 2–8 h
- Emissions test
- Usually unaffected
- Parts involved
- Hv Battery Voltage Sense W, Wiring Harness, Bms
Related codes
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- P0B9FHybrid/EV Battery Voltage Sense U Circuit
- P0BA4Hybrid/EV Battery Voltage Sense V Circuit
- P0BAEHybrid/EV Battery Voltage Sense X Circuit
- P0BB3Hybrid/EV Battery Voltage Sense Y Circuit
- P0BB8Hybrid/EV Battery Voltage Sense Z Circuit
- P0BA6Hybrid/EV Battery Voltage Sense V Circuit Low
- P0BA7Hybrid/EV Battery Voltage Sense V Circuit High
- P0BA8Hybrid/EV Battery Voltage Sense V Circuit Intermittent/Erratic
- P0BAAHybrid/EV Battery Voltage Sense W Circuit Range/Performance
- P0BABHybrid/EV Battery Voltage Sense W Circuit Low
- P0BACHybrid/EV Battery Voltage Sense W Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.