P0EFB code meaning
Battery Charger A Input Voltage Sensor C Circuit
What P0EFB means
P0EFB flags an electrical fault on the third AC input voltage channel of on-board charger A, sensor C. Channel A reports through P0D3D to P0D41, channel B through P0EF7 to P0EFA; a third channel fits chargers that read each phase of a three-phase supply separately. This is the catch-all circuit code, used when the signal is unusable without being sorted into range, low or high (P0EFC, P0EFD, P0EFE). No manufacturer documents P0EFB publicly, and GM's hybrid tables for 2011, 2012 and 2014 to 2019 never list the matching circuit code P0D3D either, catching wiring faults on sensor A only through its low and high checks. In TI's 11 kW reference design every phase is scaled by a resistor chain and centred at 1.65 V in a 3.3 V converter, so a dead channel is easy to spot. AC charging is refused or limited.
P0EFB at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0EFB
- AC charging does not start or is limited
- Possible reduced charging power on three-phase stations
- Charging fault shown in the cluster or app
Common causes of P0EFB
- Most likelyFailed measuring channel C on the charger board (divider, amplifier or converter input)
- PossibleOpen or loose sense connection for this phase inside the charger or at the AC inlet harness
- Less likelyCharger software marking a valid channel as faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Battery charger a input voltage sensor cWiring harnessOn board charger
What each part of P0EFB means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| FB | The exact fault in that area. |
What to do next
- Note P0EFB and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0EFB
What does P0EFB mean?
P0EFB means "Battery Charger A Input Voltage Sensor C Circuit". P0EFB flags an electrical fault on the third AC input voltage channel of on-board charger A, sensor C. It is a generic code, so it means the same on every make.
Is it safe to drive with P0EFB?
P0EFB does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P0EFB fail an emissions test?
P0EFB is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P0EFB to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P0EFB clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.