U0111
NetworkModule Communicationcritical severityLost Communication with Battery Energy Control Module A
What U0111 Means
Cannot communicate with the hybrid/EV high-voltage battery management system.
Symptoms
- Hybrid battery warning
- Check hybrid system light
- Reduced EV range
- Vehicle may not start
- Battery temperature warning
Common Causes
- Battery management module failure
- CAN bus wiring
- 12V supply loss to module
- High-voltage safety disconnect
- Module connector issue
Diagnostic Steps
- Check battery management module 12V fuse
- Test 12V power and ground
- Verify HV safety interlock
- Check CAN wiring to module
- Scan for battery system codes
Where to start: High-voltage system. Qualified technician required. Check 12V auxiliary supply first.
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