P2D75Battery Charging System Negative Contactor D Control Circuit Low
- Generic OBD-II code · Powertrain
- How the car detects it
- P2D75 is stored when the drive line of negative charging contactor D reads low. No manufacturer documents P2D75 publicly. How serious this is depends on wiring: a GM patent shows the coil switch either on the supply side or on the ground side. If the module switches the ground side, a short to ground at that end bypasses the switch, so the coil can energise and minus contactor D can close although nothing was commanded; charging is then locked for safety. With supply-side switching the same short simply leaves the contactor open. CARB permits makers to combine open and short faults of an output under one code, so not every system sets a separate low code. Chafed wires and wet plugs are typical. P2D76 is the high case, P2D6E the plus side.
- What you may notice
- Charging locked
- Contactor may click without a command
- Fault worse in damp weather
- Likely causes
- LikelyDrive wire of contactor D shorted to ground
- PossibleMoisture in the contactor D connector
- RareOutput stage shorted inside the module
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.