Powertrain, generic · Hybrid propulsion

P0CF4 Control Pilot Circuit Range/Performance

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modeNo

P0CF4 flags a pilot signal that is electrically present but does not fit what the vehicle expects. GM spells out the test for the Chevrolet Volt (2011-2019, VICM/HPC2): with no cord connected and the car moving at 8 km/h or more, pilot voltage divided by battery voltage must stay below 0.03 and both processor logic states must agree; in a self-test with the internal diagnostic switch closed and the charging and ventilation switches open, the ratio must sit between 0.30 and 0.55. 30 of 50 samples at 100 ms set it as Type A, MIL after one trip; older tables also require the charge door to be closed. FCA names P0CF4-00 together with P0CF3 on the Pacifica Plug-in Hybrid and the Renegade/Compass 4xe and fixes it by reflash. Opens and shorts have their own codes. Charging may fail or be refused.

Likely causes

Faulty pilot measuring or self-test circuit inside the charging/hybrid control module
Module software needing an update (FCA Pacifica and 4xe bulletins)
Moisture or dirt in the charge inlet creating a leakage path on the pilot line
Charge door position fault blocking or distorting the test (GM Volt enable condition)

Symptoms

  • Malfunction indicator lamp on after one trip (GM)
  • Charging refused or interrupted
  • Charge status indicator shows a fault

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–900
Time0.5–3 h

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

Parts involved

control pilot circuitwiring harnesson board charger

Related codes

P0CF3P0CF5P0CF6P0CF7P0CF9P0D01P0CCC

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov.