P0DB4Hybrid/EV Battery Cell Balancing Circuit C
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0DB4 belongs to the third balancing channel, C, and points to its hardware: an interrupted or shorted lead, a failed switch or a monitoring chip reporting nonsense for that cell group. A common test method sits in LG Chem's EP2730933A1, where a diagnosis resistor between cell and balancing circuit lets the controller see a defined voltage step each time the circuit is toggled; a missing or wrong step betrays the fault. Since sense and balancing leads often share pins, a sense-lead problem can show up here as well. For hybrids, CARB 13 CCR 1968.2 makes watching these parts mandatory. Audi records P0DB400 on the 2016 A3 e-tron; bulletin 93 17 04 links it to software that began CAN traffic late, so a reflash comes before any hardware work.
- What you may notice
- MIL with battery or hybrid warning
- Further cell voltage codes stored alongside
- Electric operation possibly reduced
- Likely causes
- LikelyFault in a lead shared by voltage sensing and balancing in group C
- PossibleCell monitoring chip of group C defective
- RareCorroded module connector after water ingress
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €200 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.