OBD-II code · Network
U01BF Lost Communication with Battery Management Control Module
ECU lost CAN communication with the main battery management control module (BMS) — central HV battery controller.
Is it safe to drive with U01BF?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyModule unpowered or HV interlock open
- Less likelyGateway module routing CAN messages incorrectly
- Less likelyCAN terminating resistor (120 Ω) drifted out of spec
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–10 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Bms, Can Bus
Related codes
- U01BCLost Communication With Charge Air Cooler Coolant Pump B
- U01BDLost Communication With DC/DC Converter Control Module C
- U01BELost Communication with Drive Motor A Clutch Actuator
- U0200Lost Communication With Door Control Module B
- U0201Lost Communication With Door Control Module C
- U0202Lost Communication With Door Control Module D
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.