U0108
NetworkModule Communicationmoderate severityLost Communication with Exhaust Gas Recirculation Module
What U0108 Means
Cannot communicate with the EGR system control module.
Symptoms
- Check Engine Light
- Increased NOx emissions
- EGR-related DTCs
- Poor fuel economy
- Rough idle
Common Causes
- EGR module failure
- CAN bus wiring issue
- Fuse blown
- Connector corrosion
- Carbon buildup causing module damage
Diagnostic Steps
- Check EGR module fuse
- Test power and ground
- Inspect CAN wiring
- Check connector condition
- Test EGR module directly
Where to start: Check fuses and wiring. EGR modules on diesels are prone to carbon contamination.
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