U0046high severityNetwork
Vehicle Communication Bus B Off
on 2010 Audi Q7 3.0L TDI V6 · AWD
What this code means
CAN bus B is completely offline. No communication on the secondary CAN bus.
Symptoms
- Secondary systems inoperative
- Body control functions down
- Climate control offline
- Entertainment system not communicating
Common causes
- CAN bus B wiring shorted or open
- Bus B termination resistor failure
- Module pulling down bus B
- Major connector failure
Diagnostic steps
- Measure bus B resistance
- Check bus B voltage levels
- Isolate bus B segments
- Inspect bus B connectors
Repair notes
Complete bus B failure requires systematic wiring diagnosis.
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Other Network codes on this vehicle
00003
Control Module - Defective
01304
Radio - No Communication
01312
Powertrain Data Bus - Defective
01314
Engine Control Module (ECM) - no communications
01315
Transmission Control Module (TCM) - No Communication
01316
ABS Control Module - No Communication
01317
Instrument Cluster Control Module (J285) - No Communication
01318
Immobilizer Control Module - No Communication
01321
Airbag Control Module - No Communication
U0001
High Speed CAN Communication Bus