U04ABInvalid Data Received From Hybrid/EV Battery Interface Control Module K
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- U04AB means interface module K, the eleventh, delivers data the battery controller judges invalid. What those boards report, cell voltages and temperatures, are exactly the inputs that CARB rule 1968.2, paragraph (e)(15.2.3)(A)(iv), names for monitoring in a hybrid energy storage system; this is why plug-in hybrids light the MIL for such faults, while battery-electric cars, which fall outside these rules, show a battery or system warning instead. With part of the pack unreadable, the controller has to assume the worst for those cells: tighter charge and discharge limits or a blocked charge. No manufacturer documents U04AB publicly, and an eleventh board only exists in larger packs. U01AA covers loss of contact, U0344 a software mismatch.
- What you may notice
- MIL (plug-in hybrid) or battery warning (EV)
- Charging blocked or slowed
- Reduced acceleration
- Likely causes
- PossibleFaulty temperature or voltage input on board K
- PossibleContact fault on the internal data link to module K
- RareInterface control module K internally faulty
- 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: €150 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.