U0029moderate severityNetwork
Vehicle Communication Bus B Performance
on 1998 Audi A8 4.2L V8 · AWD
What this code means
CAN bus B performance is degraded with intermittent communication issues.
Symptoms
- Secondary systems intermittent
- Body control functions erratic
- Climate control glitches
Common causes
- Wiring degradation on bus B
- Module fault on bus B
- Poor splice connections
- Aftermarket device loading bus
Diagnostic steps
- Scope bus B signals
- Check bus B termination
- Inspect bus B wiring
- Isolate modules on bus B
Repair notes
Diagnose bus B wiring and termination. Check for aftermarket device interference.
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00003
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01312
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01314
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01315
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01316
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01317
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01318
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01321
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U0001
High Speed CAN Communication Bus