Powertrain, generic

P0EFE Battery Charger A Input Voltage Sensor C Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P0EFE is stored when channel C of charger A reports more input voltage than a household or station supply can deliver. No manufacturer documents P0EFE publicly. For sensor A, GM's 2011 Volt charger module trips P0D40 when the measured AC peak exceeds 422 V for 160 ms of a 200 ms window, rated Type A; this window is far shorter than the one for the low code, presumably because overvoltage endangers the input stage. In a divider front end like the one in TI's 11 kW design, an open lower resistor or a short to the converter reference pushes the signal toward the 3.3 V limit and causes exactly this reading. Real overvoltage from the grid is rare, so the measuring channel inside the charger is the main suspect once plugs have been checked. AC charging stops at once.

Likely causes

Open lower resistor in the voltage divider of channel C
Sense signal shorted to the converter reference or a supply rail
Actual overvoltage or surge from the supply

Symptoms

  • AC charging stops within seconds of starting
  • Displayed supply voltage unrealistically high
  • Charging fault message

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–2,500
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

battery charger a input voltage sensor cwiring harnesson board charger

Related codes

P0EFDP0EFBP0EFCP0EFAP0D40

References: gsi.ext.gm.com, ti.com, law.cornell.edu.