U0078
NetworkModule Communicationhigh severityControl Module Communication Bus H Shorted To Ground
What U0078 Means
The H communication bus is shorted to ground, interrupting data exchange between modules. Multiple systems may become unresponsive.
Symptoms
- Modules not communicating
- Warning lights on
- Systems disabled
Common Causes
- Bus H wiring grounded
- Damaged harness
- Corroded connector
- Faulty control module
Diagnostic Steps
- Scan all modules
- Test bus H for ground short
- Inspect wiring routing
- Repair or replace as needed
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