OBD-II code · Powertrain (generic)
P0AC9 Hybrid/EV Battery Temperature Sensor B Circuit Intermittent/Erratic
The ECM detects a circuit intermittent/erratic fault on the hybrid/ev battery temperature sensor b circuit. Reading cannot be used reliably for control.
Is it safe to drive with P0AC9?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySensor connector not seated
- PossibleNoisy ground reference
- Less likelyConnector with intermittent contact under vibration
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
- Easy
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Usually unaffected
- Parts involved
- Hv Battery Temp Sensor B, Wiring Harness, Bms
Related codes
- P0ACEHybrid/EV Battery Temperature Sensor C Circuit Intermittent/Erratic
- P0AECHybrid/EV Battery Temperature Sensor D Circuit Intermittent/Erratic
- P0BC6Hybrid/EV Battery Temperature Sensor E Circuit Intermittent/Erratic
- P0C37Hybrid/EV Battery Temperature Sensor F Circuit Intermittent/Erratic
- P0AC6Hybrid/EV Battery Temperature Sensor B Circuit Range/Performance
- P0AC7Hybrid/EV Battery Temperature Sensor B Circuit Low
- P0AC8Hybrid/EV Battery Temperature Sensor B Circuit High
- P0ACAHybrid/EV Battery Temperature Sensor C Circuit
- P0ACBHybrid/EV Battery Temperature Sensor C Circuit Range/Performance
- P0ACCHybrid/EV Battery Temperature Sensor C Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.