P0BC9
Hybrid/EV Battery Pack Cooling Fan 1 Sense Circuit Low
The HV battery pack cooling fan 1 sense circuit reports a sense circuit low fault. Fan speed feedback is unreliable.
- 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.
- Sense wire shorted to groundCommon
- Tachometer internal shortPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Hv Battery Cooling Fan 1 Sense
- Wiring Harness
- Bms
P0BC9 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.