P0EFD code meaning
Battery Charger A Input Voltage Sensor C Circuit Low
What P0EFD means
P0EFD reports that the reading of input voltage sensor C in charger A sits below its plausible band. No manufacturer documents P0EFD publicly. GM's 2011 Volt charger module gives a reference for sensor A: once AC is detected at the inlet, a peak value under 90 V for 1500 ms within a 1875 ms window sets P0D3F, Type A with the warning lamp after one trip. Causes on the measuring side are a short to ground on the sense path, a shorted lower divider resistor or a missing reference for the converter. A phase that is genuinely dead at the supply, such as a tripped breaker on one leg of a three-phase station, can produce the same picture, so the incoming voltage is measured first. Mains undervoltage proper has its own codes such as P0D27; the high counterpart is P0EFE.
P0EFD at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor0.3 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0EFD
- AC charging refused right after plugging in
- Charging works on a different station or outlet
- Charging fault message
Common causes of P0EFD
- Most likelyDefective divider or converter input for channel C in the charger
- PossibleOne phase missing at the supply (tripped breaker or fault in the station or cable)
- PossibleSense path of channel C shorted to ground
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 P0EFD means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| FD | The exact fault in that area. |
What to do next
- Note P0EFD 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 P0EFD
What does P0EFD mean?
P0EFD means "Battery Charger A Input Voltage Sensor C Circuit Low". P0EFD reports that the reading of input voltage sensor C in charger A sits below its plausible band. It is a generic code, so it means the same on every make.
Is it safe to drive with P0EFD?
P0EFD does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P0EFD fail an emissions test?
P0EFD 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 P0EFD to fix?
Difficulty: workshop only. A typical repair takes 0.3 to 4 hours of work. This is a job for a workshop.
Will P0EFD clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.