|  | TEST RESULTS | 
| 0 | PRELIMINARY CHECKS | ALL OK | PROBLEMS ENCOUNTERED | ACTION | 
|---|
|  | Check, by operating the horn control on the steering wheel, that the travel is correct. | Move on to Step 1 | Travel not correct. | Remove the steering wheel    Op. 4110A10  STEERING WHEEL - R+R FOR REPLACEMENT OR CHECKS and check that there are no impediments to the travel. If there are problems, replace the faulty component | 
| 1 | CHECK ON INTERVENTION OF FUSE | ALL OK | PROBLEMS ENCOUNTERED | ACTION | 
|---|
|  | Check that the 15A horn protective fuse F10 has not blown. | Move on to Step 2 | The fuse has blown. | Replace the fuse and search for the cause of the problem. | 
| 2 | RELAY CHECK | ALL OK | PROBLEMS ENCOUNTERED | ACTION | 
|---|
|  | Check that the horn relay feed T03 (20 A) is working properly. | Move on to Step 3 | Relay defective | Replace the relay | 
| 3 | RELAY ELECTRICAL CHECK | ALL OK | PROBLEMS ENCOUNTERED | ACTION | 
|---|
|  | Undo the fastenings for the engine compartment junction unit    Op. 5505A13  ADDITIONAL JUNCTION UNIT IN ENGINE COMPARTMENT - R.R. and check, using a tester, that the power supply for the horn relay feed is correct. | Move on to Step 4 | Power supply interrupted | Restore correct power supply | 
| 4 | HORN CHECK | ALL OK | PROBLEMS ENCOUNTERED | ACTION | 
|---|
|  | Remove the horn    Op. 5550B30 L/H OR R/H HORN (ONE) - R+R and connect it directly to a battery charger. Check that a sound produced and that there are no unpleasant noises (knocking/buzzing). | End of diagnosis | Sound faulty or no sound produced. | Replace the horn    Op. 5550B30 L/H OR R/H HORN (ONE) - R+R |