U01AELost Communication With 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
- U01AE concerns battery interface control module O, which only exists in systems with at least fifteen monitoring nodes; no manufacturer documents the code publicly. Wikipedia distinguishes three ways to organise battery management: centralised (one controller wired to every cell), modular (several controllers, each covering a group of cells) and distributed (a board per cell with a single communication cable). Only the last two need an internal link and thus codes like this one; for modular hardware the article cites a ceiling of 255 nodes, while NXP specifies 63 for one MC33771C chain. With O missing, its section of the pack is unmonitored, and the controller will typically warn, limit power and hold off charging until the board is heard again.
- What you may notice
- Warning lamp, power reduced
- Charging postponed or refused
- Likely causes
- LikelyInternal link to module O interrupted
- PossibleBattery interface control module O defective
- RareBoard O without supply from its cell group
- 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.