U0293 U0xxx · Network (U) High severity
Lost Communication with Hybrid / EV Battery Energy Control Module
The battery management controller is not responding. The vehicle will not ready-up, and this is high-voltage territory.
Severity guidance: High — stop driving and diagnose now; risk of further damage
Symptoms you will notice
- Will not ready
- HV battery warning
- No charging possible
Common causes
Ordered from most to least likely — start at the top.
- 1 BMS supply or earth fault
- 2 HV interlock open
- 3 CAN fault
- 4 Failed BMS board
How to diagnose it
Cheapest and least invasive first — most of these codes are not a parts problem.
- ✓ Only HV-qualified technicians should proceed beyond basic checks.
- ✓ Verify the service disconnect and HV interlock are correctly seated.
- ✓ Check the BMS low-voltage supply and earth.
- ✓ Read the BMS directly with a capable EV tool.
Repair options
- Restore the interlock and supply
- Repair the wiring
- Replace the BMS (HV-qualified work)
U0293 — frequently asked questions
Can I charge the car? +
No. Charging requires BMS supervision; without it the contactors stay open.
Is this a battery replacement job? +
Rarely. Most cases are interlock, supply or communication faults, not a failed pack.
Confirm the diagnosis before you buy parts
Send us the code, freeze-frame data and the vehicle — our engineers will tell you what to test first.