Powertrain, generic · Hybrid propulsion

P0CF8 Control Pilot Charging Switch A Circuit/Open

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

On the vehicle side the pilot is loaded permanently by about 2.7 kΩ, which drops the station's +12 V to roughly 9 V once a cable is connected. To ask for energy the vehicle closes charging switch A, often called S2, which adds a 1.3 kΩ branch and brings the level to about 6 V, the state in which the station closes its contactors. P0CF8 reports that the control circuit of this switch is open, so the module cannot operate it. No manufacturer documents this code publicly; GM tests the same switch on the Chevrolet Volt only for plausibility (P0CF9, normalized pilot voltage 0.14-0.28 in a self-test), and CARB requires plug-in vehicles to monitor charging system function. Shorts are P0CFA/P0CFB, a switch that will not close is P0CFD. Expect a car the station recognises that still never starts charging.

Likely causes

Open control wire or loose connector between module and charging switch
Charging switch or its 1.3 kΩ branch open inside the module or inlet electronics
Failed driver stage in the charging control module

Symptoms

  • Station detects the vehicle but charging never begins
  • Charging fault message after plugging in

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 switch awiring harnesson board charger

Related codes

P0CF9P0CFAP0CFBP0CFCP0CFDP0CFE

References: law.cornell.edu, en.wikipedia.org, gsi.ext.gm.com.