Network, generic

U01AE Lost Communication With Hybrid/EV Battery Interface Control Module O

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Internal link to module O interrupted
Battery interface control module O defective
Board O without supply from its cell group

Symptoms

  • Warning lamp, power reduced
  • Charging postponed or refused

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€100–3,500
Time1–10 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

hv battery interface module ocommunication bus

Related codes

U01ADU01AFU04AFU0348

References: en.wikipedia.org, nxp.com, law.cornell.edu.