Powertrain, generic · Hybrid propulsion

P0CA0 14 Volt Power Module Current Sensor B Circuit Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P0CA0 covers short dropouts or spikes in the signal of current sensor B, the output-side sensor of the 14 V power module (DC/DC converter) in GM's numbering. Between the events the reading looks normal, which separates it from the hard low and high faults P0C9E and P0C9F. No manufacturer documents P0CA0 publicly; GM's eAssist table only lists fixed limits for this sensor, below 2 A and above 123 A, each judged over 1.5 s in 2 s, and the cross-check P0CC5. CARB paragraph (e)(15.3.1) still expects such inputs to be monitored without pause. Vibration, a loose module connector, corroded grounds or poor 12 V cable connections are the first things to inspect; freeze-frame data helps to catch the moment.

Likely causes

Loose or fretting connector at the power module
Corroded ground or 12 V output connection
Current sensor B failing intermittently inside the module

Symptoms

  • Warning lamp that comes and goes
  • Occasional dim lights or voltage messages

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–1,800
Time1–4 h

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

Parts involved

pm14v current sensor bwiring harnessdcdc converter

Related codes

P0C9CP0C9DP0C9EP0C9FP0A8AP0CC5

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