OBD-II code · Powertrain (generic)
P0EF9 Battery Charger A Input Voltage Sensor B Circuit Low
The ECM detects a low fault on the battery charger a input voltage sensor b circuit. Reading cannot be used reliably for control.
Is it safe to drive with P0EF9?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelySignal wire shorted to ground
- PossibleInternal sensor short
- Less likelyConnector pins corroded - high contact resistance
Symptoms
- Charge status indicator shows fault
- Charging may not start or interrupts
- Slower-than-expected charge rate
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–5 h
- Emissions test
- Usually unaffected
- Parts involved
- Battery Charger A Input Voltage Sensor B, Wiring Harness, Bms
Related codes
- P0D3FBattery Charger A Input Voltage Sensor A Circuit Low
- P0EFEBattery Charger A Input Voltage Sensor C Circuit Low
- P0EF6Drive Motor C Temperature Sensor Circuit Intermittent/Erratic
- P0EF7Battery Charger A Input Voltage Sensor B Circuit
- P0EF8Battery Charger A Input Voltage Sensor B Circuit Range/Performance
- P0EFABattery Charger A Input Voltage Sensor B Circuit High
- P0EFBBattery Charger A Input Voltage Sensor B Circuit Intermittent/Erratic
- P0EFCBattery Charger A Input Voltage Sensor C Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.