U0120moderate severityNetwork
Lost Communication with Starter/Generator Module
on 2010 Audi R8 5.2L V10 (Gen 1, 525hp) · AWD
What this code means
Cannot communicate with the integrated starter-generator in start-stop or mild hybrid vehicles.
Symptoms
- Start-stop system disabled
- Engine will not auto-restart
- Mild hybrid assist not available
- Warning message displayed
Common causes
- Starter-generator module failure
- CAN bus wiring
- Module power loss
- Belt-driven starter-generator fault
Diagnostic steps
- Check module fuse
- Test power and ground
- Check CAN wiring
- Test starter-generator operation
- Inspect drive belt condition
Repair notes
Check power supply and belt condition on belt-driven starter-generators.
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00003
Control Module - Defective
01304
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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