U027BLost Communication With Battery Charger Control Module D
- Generic OBD-II code · Network
- How the car detects it
- U027B refers to a fourth charger unit. In multi-charger designs the units also split the control task; in a dual charger system patented by Lear, two chargers feed the battery in parallel, one regulating voltage and the other regulating current. If one partner falls silent, the remaining unit has to carry the job alone or charging is stopped. U027B is set when the supervising controller loses all messages from charger D, whereas U057C stands for messages from D that arrive but fail checks. No manufacturer documents U027B or a fourth on-board charger publicly. The CARB rule for plug-in hybrids exempts charging faults that cannot be told apart from a supply problem outside the car. Expect slower or interrupted charging.
- What you may notice
- Charging power lower than usual
- Charging session aborted with a warning
- Likely causes
- LikelyLow-voltage supply, fuse or wake-up of charger D missing
- PossibleBus wiring to charger D damaged or connector wet
- RareCharger D control board faulty
- Repair
- Hard · Usually a job for a workshop.Typical cost: €0 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.