P0DB6Hybrid/EV Battery Cell Balancing Circuit C Stuck Off
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P0DB6 says that the bleed function of group C does not respond: commanded on, circuit C stays dead. In LG Chem's US20110285539A1 such a case shows up because a test capacitor charged to cell voltage is not emptied through the balancing path and keeps a high residual voltage. Typical culprits are an open resistor, a transistor that no longer conducts or a broken cell tap. While driving there is little to feel; the effect is that group C cannot be trimmed, so the strongest cell there caps every full charge. CARB 13 CCR 1968.2 demands detection of this. Ford documents P0DB6 in the 2018 OBD summary for its hybrids, one of fourteen balancing circuits there; a 75 mV spread inside the six-cell group, seen on two consecutive power cycles before the contactors close, triggers it.
- What you may notice
- MIL with battery warning
- Shorter charging sessions and lower usable capacity
- Likely causes
- LikelyBleed resistor of circuit C open
- PossibleBalancing transistor of circuit C not conducting
- RareBroken cell tap or weld in group C
- 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: €300 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.