Powertrain, generic

P0EF7 Battery Charger A Input Voltage Sensor B Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P0EF7 stands for an electrical fault in the second input voltage sensor of on-board charger A, the measuring channel that reads the AC supply voltage coming from a wallbox, station or household outlet. Chargers designed for several phases or split-phase supply may carry more than one such channel; the first one, sensor A, uses P0D3D to P0D41. This general code applies when the signal is unusable but not classified as range, low or high, which are P0EF8, P0EF9 and P0EFA. No manufacturer documents P0EF7 publicly. In its 2019 plug-in hybrid tables GM reads sensor A through a pulse duty ratio, so a broken line shows up as a stuck 0 % or 100 %. CARB requires plug-in vehicles to monitor charging system performance. As long as the supply voltage cannot be confirmed, AC charging is refused or limited.

Likely causes

Fault in the voltage sensing stage inside the charger
Open or high-resistance signal line between sensor and controller
Corroded low-voltage connector at the charger

Symptoms

  • AC charging does not start or stops shortly after start
  • Charging fault message in the cluster or app
  • DC fast charging usually unaffected

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 bwiring harnesson board charger

Related codes

P0EF8P0EF9P0EFAP0EFBP0D3D

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