U0073critical severityNetwork
Control Module Communication Bus A Off
on 2011 Audi A8 3.0L Supercharged V6 · AWD
What this code means
CAN bus A is not communicating. Complete loss of communication on the primary bus.
Symptoms
- Multiple systems down
- Multiple warning lights
- Vehicle may not start
- No scan tool communication
Common causes
- CAN bus wiring shorted or open
- Termination resistor failure
- Module failure shorting the bus
- Major wiring harness damage
Diagnostic steps
- Check CAN bus voltage levels
- Measure bus resistance
- Isolate bus segments
- Check for physical damage to wiring
Repair notes
Major network failure. Systematic diagnosis required.
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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