U0025moderate severityNetwork
Control Module Communication Bus B Open
on 2002 Audi A6 3.0L V6 · AWD
What this code means
An open circuit in communication bus B breaks the data link between modules. Affected modules cannot exchange data.
Symptoms
- Lost communication
- Warning lights on
- Inoperative systems
Common causes
- Broken bus B wire
- Loose connector
- Faulty control module
- Corroded terminals
Diagnostic steps
- Scan all modules
- Check bus B continuity
- Inspect connectors for damage
- Verify module power and ground
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