OBD-II code · Network
U01B0 Lost Communication With Battery Monitor Module
ECU lost communication with the battery monitor module (12V battery state-of-charge/health monitoring).
Is it safe to drive with U01B0?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyModule unpowered
- 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
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–2 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Battery Monitor Module, Can Bus
Related codes
- U01ADLost Communication With Hybrid/EV Battery Interface Control Module N
- U01AELost Communication With Hybrid/EV Battery Interface Control Module O
- U01AFLost Communication With Hybrid/EV Battery Interface Control Module P
- U01B1Lost Communication With Particulate Matter Sensor B
- U01B2Lost Communication With Planetary Gear Set Control Module
- U01B3Lost Communication With Brake Blending Actuator
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.