Test results

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

Check that the protective fuse for the horn in the engine compartment junction unit has not been activated

 See E3010 HORNS

Move on to Step 2

The fuse has blown.

Replace the fuse and search for the cause of the problem.

Check that horn control relay T03 is working properly.

Move on to Step 3

Relay defective

Replace the relay

Undo the fastenings for the engine compartment control unit

 Op. 5505A28 CONTAINER FOR ADDITIONAL JUNCTION UNIT IN ENGINE COMPARTMENT - R.R.

and check, using a tester, that the power supply for the horn relay feed is correct.

 See E3010 HORNS

Move on to Step 4

Power supply interrupted

Restore the correct power supply

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 is 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