U04AFInvalid Data Received From Hybrid/EV Battery Interface Control Module O
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- U04AF concerns interface module O, the fifteenth board. In practice a data fault of this kind often follows work on the pack: if a replaced board and the battery controller interpret messages differently, frames arrive formally intact but fail range or counter checks. The software sibling U0348 and a search for available updates therefore belong next to this code, as does U01AE for a module that stopped sending. GM's 2015 note PIC6080 for the 2011–2014 Volt, ELR and Ampera says to reprogram the battery and hybrid controllers first when cell codes are spread over several pack sections, and to call technical assistance only when all of them sit on one interface board. No maker documents U04AF; the letter O only exists on very large packs.
- What you may notice
- Battery warning shortly after a battery repair
- Reduced power or charging
- Likely causes
- LikelySoftware levels of replaced board and battery controller do not match
- PossibleInterface control module O faulty
- RarePlug not fully seated after pack repair
- 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 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.