P2BCC code meaning
Battery Charging System Negative Contactor B Stuck Closed
What P2BCC means
P2BCC says negative charging contactor B is still closed although the module ordered it open – in practice fused contacts on the return side. Mercedes-Benz lists it in the DC charge connection unit next to P2BC5 and P0E8929 (DC input current too high); the plug-in hybrid, EQB or eSprinter then cannot be started after DC charging. The bulletins name ripple and overvoltage from the station and contacts that open too late, and call for a software update and a contactor-fault reset instead of a new unit. Mazda names it OBC contactor (−) stuck on in the same bulletin and also prescribes a new Junction Box No. 2. Hyundai and Toyota patents find such welding by opening one pole while the other stays closed and checking the voltage behind it. P2BC5 is the plus side, P2BCD the reverse fault.
P2BCC at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor0.5 to 10 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2BCC
- Vehicle will not start after DC charging (Mercedes)
- High-voltage system warning
- Charging blocked
Common causes of P2BCC
- Most likelyContacts of negative contactor B welded at the end of charging
- PossibleCharging module software (Mercedes update)
- PossibleCurrent ripple or overvoltage from the DC station
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Bcs neg contactor bWiring harnessBms
What each part of P2BCC means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| B | Area: hybrid propulsion. |
| CC | The exact fault in that area. |
What to do next
- Note P2BCC and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2BCC
What does P2BCC mean?
P2BCC means "Battery Charging System Negative Contactor B Stuck Closed". P2BCC says negative charging contactor B is still closed although the module ordered it open – in practice fused contacts on the return side. It is a generic code, so it means the same on every make.
Is it safe to drive with P2BCC?
Drive gently and only to a workshop. With P2BCC the car can go into limp mode (reduced power) to protect itself.
Will P2BCC fail an emissions test?
P2BCC is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P2BCC to fix?
Difficulty: workshop only. A typical repair takes 0.5 to 10 hours of work. This is a job for a workshop.
Will P2BCC clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.