P0D42 code meaning
Battery Charger 14 Volt Output Voltage Sensor Circuit
What P0D42 means
P0D42 is the circuit code for the sensor that measures voltage at the 14 V output of the battery charger, a low-voltage DC stage built into the on-board charger and distinct from the vehicle's main DC/DC converter. GM's charger module in the Volt and ELR has such an output and monitors its voltage with P0D43-P0D45, yet no manufacturer publishes P0D42 itself. A Ford patent explains the purpose of such a stage: a small converter inside the charger keeps the 12 V bus supplied during charging, so the main contactors and the large converter can stay off. CARB requires circuit checks on inputs of this kind. A fault can leave the 12 V side unsupported while plugged in or interrupt charging; driving is not directly affected.
P0D42 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 P0D42
- 12 V battery discharges while the car is plugged in
- Charging is interrupted
Common causes of P0D42
- PossibleOpen or shorted voltage sense circuit of the charger's low-voltage stage
- PossiblePoor 12 V or ground connection at the charger
- Less likelyFailed on-board charger electronics
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Battery charger 14v output voltage sensorWiring harnessOn board charger
What each part of P0D42 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 42 | The exact fault in that area. |
What to do next
- Note P0D42 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 P0D42
What does P0D42 mean?
P0D42 means "Battery Charger 14 Volt Output Voltage Sensor Circuit". P0D42 is the circuit code for the sensor that measures voltage at the 14 V output of the battery charger, a low-voltage DC stage built into the on-board charger and distinct from the vehicle's main DC/DC converter. It is a generic code, so it means the same on every make.
Is it safe to drive with P0D42?
P0D42 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will P0D42 fail an emissions test?
P0D42 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 P0D42 to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P0D42 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.