Powertrain, generic · Hybrid propulsion

P0C9F 14 Volt Power Module Current Sensor B Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P0C9F reports an output current from sensor B of the 14 V power module that exceeds what the converter can plausibly supply. GM's 2013 eAssist table 13OBDG05C sets it once the APM output current reading tops 123 A while calculated APM input power is between 0.25 and 1.8 kW, supply voltage is 9 to 32 V and the vehicle is in run/crank; 1.5 s out of a 2 s window fail it, Type B, two trips. Pairing a very high current with modest input power separates a sensor fault from a genuine heavy load. A signal shorted to voltage or an internal sensor defect is typical. P0C9E is the low counterpart, P0A89 the input sensor's high code, and P0CC5 compares both sensors.

Likely causes

Internal defect of output current sensor B
Sensor signal shorted to a voltage source
Poor ground of the power module shifting the reading

Symptoms

  • Check-engine lamp
  • Converter output reduced, 12 V battery discharging

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

P0C9EP0C9CP0C9DP0CA0P0A89P0CC5

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