P0EFABattery Charger A Input Voltage Sensor B Circuit High
- Generic OBD-II code · Powertrain
- How the car detects it
- With P0EFA, the signal from the second input voltage sensor of charger A, sensor B, lies above the plausible window. No manufacturer documents P0EFA publicly. GM's comparable check for sensor A, P0D40 in its 2019 plug-in hybrid tables, trips at a duty cycle of 92 % or more but below 100 %, or at exactly 0 %, in 30 of 40 samples, and is rated Type B. Electrically this points to a short to a supply voltage, an open signal line pulled up by the input stage, or a defective sensing stage inside the charger. Since the measuring channel normally sits on the charger board, the charger itself becomes the prime suspect once plugs and pins have been checked. AC charging is refused or ends soon after it started; the low-side sibling is P0EF9.
- What you may notice
- AC charging refused or ends after a few seconds
- Charging fault message
- Indicated charging power implausible
- Likely causes
- LikelyDefective measuring stage on the charger board
- PossibleOpen signal line pulled high by the input circuit
- RareSignal shorted to a supply voltage
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €80 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.