U04A9Invalid Data Received From Hybrid/EV Battery Interface Control Module I
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- U04A9 refers to interface module I, the ninth position in the series. It is the third of the codes Volkswagen lists for the ID.4: in the dealer analysis list of July 2024, U04A9 appears beside U04A1 and U04A5 as a CMCe fault in address 8C, valid for model years 2021 to 2024, with an electrical system message as the complaint. According to Wikipedia the smaller ID.4 battery has nine modules and the larger one twelve, so a ninth position exists in both, though VW does not say how letters map to modules. As with the other two, the helpline must be called before parts are changed. U01A8 marks loss of contact with I, U0342 a software conflict. From J (U04AA) on, the series presupposes larger packs.
- What you may notice
- Electrical system warning message
- Charging or power restricted
- Likely causes
- LikelySoftware issue in the battery electronics (VW ID.4 case)
- PossibleInterface control module I internally faulty
- RareContact fault on the pack-internal link to module I
- 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: €100 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.