P0DDDHybrid/EV Battery Cell Balancing Circuit M Stuck On
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P0DDD reports a balancing path of group M that keeps conducting. Ford's 2015 hybrid OBD summary places it in the BECM monitor, judged at power-up before the contactors close: 100 ms, six cells per circuit, more than 75 mV from the average, two consecutive power cycles. A properly working chip should never leave a channel on indefinitely. Infineon's TLE9012DQU, for example, gives each cell its own balancing timer of up to about 3.9 hours and ends balancing on its own once that runs out, or when its over- or undercurrent check trips. If group M still loses charge after such limits, the switch itself is most likely shorted. Expect a low group M after a night of parking. Inactive counterpart: P0DDE.
- What you may notice
- Check engine light at start-up
- Group M noticeably low after overnight parking
- Raised module temperature near group M
- Likely causes
- LikelyShorted balancing switch of group M that no timer can stop
- PossibleDamaged external balancing transistor on the board for M
- RareHigh self-discharge cell in group M imitating a stuck switch
- 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 – €4,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.