Powertrain, generic · Hybrid propulsion

P0C9D 14 Volt Power Module Current Sensor B Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P0C9D means the output current reported by sensor B of the 14 V power module is electrically valid but implausible for the operating state. No manufacturer documents this code publicly. GM's 2013 eAssist table checks this kind of plausibility through the correlation code P0CC5 instead: the output power derived from sensor B is compared with the input power from sensor A multiplied by an efficiency factor between 0.90 and 0.99, and a gap above 0.4 kW for 3.75 s within 5 s sets it, Type B. That test is blocked while P0C9E or P0C9F is active. A sensor with offset or gain drift is the usual reason, rarely a converter whose real output deviates. The driver may notice only a warning lamp or a 12 V battery that stays low.

Likely causes

Offset or gain drift of current sensor B
High resistance at the 12 V output cable or ground
Converter output really differing from the commanded power

Symptoms

  • Warning lamp without obvious driveability change
  • 12 V battery charge state remaining low

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

P0C9CP0C9EP0C9FP0CA0P0CC5P0A87

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