OBD-II code · Network
U0112 Lost Communication with Battery Energy Control Module "B"
The Battery Energy Control Module "B" has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. The second battery-energy controller is silent, limiting high-voltage system availability. Typical causes are loss of power or ground at the module, an open or shorted CAN/LIN bus wire, a connector fault, or an internal module failure.
Is it safe to drive with U0112?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyBEM-B unpowered
- PossibleCAN wiring to BEM-B broken
- Less likelyGateway module routing CAN messages incorrectly
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
- 2–8 h
- Emissions test
- Usually unaffected
- Parts involved
- Battery Energy Control Module, Can Bus Wiring
Related codes
- U010FLost Communication With Air Conditioning Control Module
- U0110Lost Communication with Drive Motor Control Module
- U0111Lost Communication with Battery Energy Control Module
- U0113Lost Communication with Battery Charger A Control Module
- U0114Lost Communication with 4WD Clutch Control Module
- U0115Lost Communication with ECM/PCM "B"
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.