U007E
Control Module Communication Bus L Off
The control module communication bus L is off — the gateway has shut down or isolated this bus, often due to repeated bus errors or a "bus off" event in the CAN controller.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
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
Common causes
Ordered by how often each turns out to be the cause.
- CAN controller in bus-off stateCommon
- Gateway module routing CAN messages incorrectlyLess likely
- CAN terminating resistor (120 Ω) drifted out of specLess likely
Parts involved
- Bus L Gateway
- Bus L Wiring
U007E is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.