The control module communication bus H 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.
Medium severity. Can I keep driving?It depends on which control module has dropped out. If it affects the engine, brakes, or steering, do not continue your trip: call for roadside assistance.
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
Most likely causes
- CAN controller in bus-off state from repeated errors
- Gateway module routing CAN messages incorrectly
- CAN terminating resistor (120 Ω) drifted out of spec
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: hard
- It can trigger limp mode.
What each character of U007A means
- U: Communication network
- 0: Generic code: same on every make
- 0: Subsystem depends on the code range
- 7A: Specific fault in that system
Frequently asked questions
Can I keep driving with code U007A?
It depends on which control module has dropped out. If it affects the engine, brakes, or steering, do not continue your trip: call for roadside assistance.
What causes code U007A?
The most common causes are: cAN controller in bus-off state from repeated errors; gateway module routing CAN messages incorrectly; cAN terminating resistor (120 Ω) drifted out of spec.
Related codes
- U007BControl Module Communication Bus I Off
- U007CControl Module Communication Bus J Off
- U007DControl Module Communication Bus K Off
- U007EControl Module Communication Bus L Off
- U007FControl Module Communication Bus M Off
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.