Powertrain, generic · Hybrid propulsion

P0C9E 14 Volt Power Module Current Sensor B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P0C9E is set when current sensor B of the 14 V power module reads too little. GM documents it for the eAssist accessory power module in its 2013 table 13OBDG05C: the APM output current measured by the sensor must stay below 2 A for 1.5 s, counted as 60 of 80 samples at 25 ms, with the vehicle in run/crank; the code is Type B, so the MIL comes on after the second failing trip. Since an operating converter feeds considerably more current to the 12 V side, such a reading points to an open signal path, a grounded signal line or a dead sensor. The input-side counterpart is P0A88, the high fault P0C9F. Without valid current data the system may restrict the converter, and the 12 V battery can run down.

Likely causes

Output current sensor B failed inside the module
Sensor signal open or shorted to ground
Converter not delivering output although enabled

Symptoms

  • Check-engine lamp after two drives
  • Low 12 V voltage, flickering lights or warning messages

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–1,800
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

P0C9FP0C9CP0C9DP0CA0P0A88P0CC5

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