Powertrain, generic · Hybrid propulsion

P0D42 Battery Charger 14 Volt Output Voltage Sensor Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

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.

Likely causes

Open or shorted voltage sense circuit of the charger's low-voltage stage
Poor 12 V or ground connection at the charger
Failed on-board charger electronics

Symptoms

  • 12 V battery discharges while the car is plugged in
  • Charging is interrupted

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–2,500
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

battery charger 14v output voltage sensorwiring harnesson board charger

Related codes

P0D43P0D44P0D45P0D46P0D47P0D5B

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