Multiple modules stored lost-communication codes when a corroded ground connection developed excessive voltage drop.
Why this matters
The value of this case is the order of evidence and the verification step. The same symptom on another vehicle may have a different cause.
Evidence to capture first
- Full network scan
- ECM powers and grounds
- Loaded ground voltage drop
- Harness and ground-eyelet condition
A disciplined path
- Map which modules were online
- Verify supply under load
- Measure the ground path during the fault
- Restore the connection and stress-test the circuit
Decision point
Stable communication and a low loaded voltage drop verified the ground repair.
Source desk
Use current model-specific service information for specifications, connector locations, disabling procedures, and tightening values. The following public resources support the broader safety or system context used in this guide.
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