P0CF9Control Pilot Charging Switch A Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- How the car detects it
- Charging switch A is the vehicle-side switch that adds a resistor across the pilot to tell the charging station that the car is ready to take current. P0CF9 says the effect of that switch is implausible. GM documents the check for the Chevrolet Volt 2011-2019 (VICM/HPC2): with the cord unplugged, the controller closes its diagnostic switch together with the charging switch and expects the ratio of pilot voltage to battery voltage between 0.14 and 0.28; outside that band in 30 of 50 samples at 100 ms the code sets, Type A, MIL after one trip. The test only runs once the pilot circuit check has passed in the same key cycle, and it comes before the ventilation switch test P0D01. Opens and shorts of the switch are P0CF8, P0CFA and P0CFB. A car with this fault may be recognised but not charge.
- What you may notice
- Malfunction indicator lamp on (GM Type A)
- Charging does not start or is refused
- Likely causes
- PossibleCharging switch resistor branch out of tolerance or switch with high contact resistance
- PossibleInternal fault in the VICM/charging module measuring or switching circuit
- RareLeakage on the pilot line from moisture in the charge inlet
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.