01312critical severityNetwork
Powertrain Data Bus - Defective
on 1999 Audi A8 4.2L V8 · AWD
What this code means
The powertrain CAN bus has a fault and modules cannot share data. Similar to OBD U0001 (High Speed CAN Communication Bus).
Symptoms
- Multiple modules not communicating
- Several warning lights on
- Engine or transmission limp mode
Common causes
- Damaged CAN bus wiring
- Shorted or open bus wire
- Faulty module dragging bus down
- Poor ground connection
Diagnostic steps
- Check CAN high/low resistance
- Inspect bus wiring for damage
- Disconnect modules to isolate fault
- Repair wiring or replace faulty module
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Other Network codes on this vehicle
00003
Control Module - Defective
01304
Radio - No Communication
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
U0002
High Speed CAN Communication Bus Performance