P0EFA code meaning
Battery Charger A Input Voltage Sensor B Circuit High
What P0EFA means
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.
P0EFA 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 P0EFA
- AC charging refused or ends after a few seconds
- Charging fault message
- Indicated charging power implausible
Common causes of P0EFA
- Most likelyDefective measuring stage on the charger board
- PossibleOpen signal line pulled high by the input circuit
- Less likelySignal shorted to a supply voltage
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 bWiring harnessOn board charger
What each part of P0EFA means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| FA | The exact fault in that area. |
What to do next
- Note P0EFA 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 P0EFA
What does P0EFA mean?
P0EFA means "Battery Charger A Input Voltage Sensor B Circuit High". With P0EFA, the signal from the second input voltage sensor of charger A, sensor B, lies above the plausible window. It is a generic code, so it means the same on every make.
Is it safe to drive with P0EFA?
P0EFA does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P0EFA fail an emissions test?
P0EFA 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 P0EFA to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P0EFA clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.