Powertrain, generic · Hybrid propulsion

P0D4B Battery Charger 14 Volt Output Current Sensor Circuit Intermittent/Erratic

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P0D4B covers an erratic or intermittent signal from the current sensor in the battery charger's 14 V output. No manufacturer documents it publicly; GM's Volt and ELR charger module uses only the low and high codes P0D49 and P0D4A for this measurement. As a Ford patent describes, such a charger-internal low-voltage stage can support the 12 V system during charging, so an unsteady current value may make the charger cut that stage in and out. CARB's comprehensive component requirements cover sporadic signal faults of inputs in general. Likely causes are loose connectors at the charger, internal contact problems or electrical interference; repair usually starts with the charger's low-voltage connections before the charger itself is replaced.

Likely causes

Loose low-voltage connector or ground at the charger
Intermittent contact in the charger's current sense circuit
Electrical interference on the low-voltage network

Symptoms

  • Charging interrupts now and then
  • 12 V battery voltage fluctuates while plugged in

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€50–2,500
Time0.5–4 h

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

Parts involved

battery charger 14v output current sensorwiring harnesson board charger

Related codes

P0D47P0D48P0D49P0D4AP0D46

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