OBD-II · Network and communication (U)
U0111
Lost communication with battery energy control module A
What it means
Another module has stopped receiving messages from the control unit that manages the high-voltage (hybrid/EV) battery.
Symptoms
- Hybrid/EV system warning
- Car will not go into READY or drive mode
- Charging not possible
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | weak or flat 12V battery (very common on hybrids and EVs) |
| 02 | blown fuse for the battery management module |
| 03 | loose or corroded connector at the high-voltage battery |
| 04 | CAN wiring fault |
| 05 | failed battery management module |
What to check, step by step
- 01Test and charge the 12V battery first
- 02Check the battery management fuse
- 03Check whether the battery management module answers a scan tool
- 04High-voltage battery connectors and internals must only be checked by a high-voltage qualified technician