P0DD9Hybrid/EV Battery Cell Balancing Circuit L 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
- P0DD9: the balancing path of group L will not switch off. The 2018 edition of Ford's hybrid OBD summary contains the code; the BECM catches it at power-up with the contactors still open, in a 100 ms check that compares each of the six cells of circuit L with the average and fails above 75 mV, again over two power cycles. GM shows a different route in its 2013 eAssist table: code P1B33 compares the reported balancing switch status with the commanded one and fails after 7 of 10 samples, as a two-trip fault. A switch that reads on while it should be off is exactly what P0DD9 describes. While parked the group drains, and the warm resistor stresses the module. Inactive opposite: P0DDA.
- What you may notice
- Check engine light after switching on
- Group L lower than the others after standing
- Less electric range
- Likely causes
- LikelyBalancing switch of group L shorted
- PossibleBalancing command for L not cleared by the monitoring electronics
- RareSwitch status feedback of channel L reporting on although the switch is open
- 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.