U0205moderate severityNetwork
Lost Communication with Horn Control Module
on 2015 Audi Q7 3.0L Supercharged V6 (TFSI, 280 hp) · AWD
What this code means
Cannot communicate with the horn control module on vehicles with electronic horn management.
Symptoms
- Horn not sounding
- Horn intermittent
- Panic alarm no horn output
- Theft alarm no horn
Common causes
- Horn relay module failure
- CAN bus wiring
- Module power loss
- Fuse blown
- Horn assembly failure
Diagnostic steps
- Check horn fuse
- Test horn relay
- Check CAN wiring to horn module
- Test horn assembly directly
- Inspect steering wheel horn switch
Repair notes
Check fuse and horn relay first. Test horn directly with jumper wire to confirm horn works.
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00003
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U0001
High Speed CAN Communication Bus