P0DADHybrid/EV Battery Cell Balancing Circuit A 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
- P0DAD means balancing circuit A keeps draining its cells although the controller has not asked for it: the bleed switch is stuck closed and the resistor keeps pulling those cells down. Ford uses the code in the BECM of its hybrids; the 2019 OBD summary gives each of 14 circuits six cells and, at key-on with the contactors still open, rates a circuit faulty when one of its cells departs from the mean for 0.1 s by over 75 mV. Toshiba's patent US20130026994A1 detects such a shorted balancing switch with a comparator. Left alone, the affected cells sink below the rest, particularly while the car is parked, and the usable pack window shrinks. Which cells form group A is up to the maker.
- What you may notice
- Hybrid or EV battery warning with the MIL
- Cells of one group noticeably lower after the car has been parked
- Range or electric assistance decreasing over days
- Likely causes
- LikelyBalancing transistor of circuit A shorted (fails closed)
- PossibleMonitoring chip or its drive output keeps the switch enabled
- RareController software leaving a balancing request active
- 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.