P2BD1Battery Charging System Negative Contactor B Control Circuit High
- Generic OBD-II code · Powertrain
- How the car detects it
- P2BD1 flags excess voltage on the coil feed of minus-side charging contactor B, for instance from contact with a 12 V wire or an output stage that will not turn off. The risk is a coil that stays energised and keeps the return pole connected while the module believes it is open, so the module normally blocks charging. No manufacturer documents P2BD1 publicly. For negative contactor A on the Volt and ELR, GM catches this case under P0D11 when the off-state output remains within 0.4 V of supply. On the plus side Audi documents the counterpart P2BCA for the 2024 Q8 e-tron, where over-sensitive software caused the reports. CARB requires charging components to be monitored. Damaged insulation, a wiring mix-up after repair and a faulty output stage are the suspects. P2BD0 is the low case, P2BCC a welded contactor, P0D14 the contactor A twin.
- What you may notice
- Charging blocked
- High-voltage or charging fault warning
- Likely causes
- LikelyControl wire of negative contactor B shorted to supply voltage
- PossibleDriver stage stuck on
- RareOver-sensitive diagnostic software
- 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.