Horn Switch: Testing and Inspection

Horn Switch Test

'09-11 models

NOTE: SRS components are located in this area. Review the SRS component locations Locations, and precautions and procedures Service and Repair before doing repairs or servicing.

1. Remove the steering column covers Service and Repair.

2. Disconnect the dashboard wire harness 20P connector (A) from the cable reel (B).






3. Using a jumper wire, connect the dashboard wire harness 20P connector terminal No. 1 to body ground. The horn should sound.

- If the horn sounds, go to step 4.
- If the horn does not sound, check these items:
- Battery terminal fuse box No. 3 (20A) fuse.
- No. 24 (10 A) fuse in the under-dash fuse/relay box.
- Horn Service and Repair.
- Horn relay (with security) Testing and Inspection.
- MICU(without security).
- An open in the wire.





4. Reconnect the dashboard wire harness 20P connector (A) to the cable reel (B).





5. Remove the driver's airbag assembly Driver's Airbag Replacement, and disconnect the horn switch 1P positive terminal (C) from the driver's airbag.

6. Check for continuity between the dashboard wire harness 20P connector terminal No. 1 and the steering wheel switch 20P connector terminal No. 11.

- If there is continuity, go to step 7.
- If there is no continuity, replace the cable reel Service and Repair.





7. Check for continuity between the steering wheel switch 20P connector terminal No. 11 and the horn switch 1P positive terminal.

- If there is continuity, check the installation of the driver's airbag assembly and the steering wheel. If OK, replace the driver's airbag assembly.
- If there is no continuity, repair an open in the wire.





'12 model

NOTE:

- SRS components are located in this area. Review the SRS component locations Locations, and precautions and procedures Service and Repair before doing repairs or servicing.
- Before testing, check the No. 24 (10 A) fuse in the under-dash fuse/relay box. If the fuse is blown, repair a short to ground in the No. 24 (10 A) fuse circuit.

1. Remove the steering column covers Service and Repair.

2. Disconnect the dashboard wire harness 20P connector (A) from the cable reel (B).






3. Connect dashboard wire harness 20P connector terminal No. 1 and No. 2 with a jumper wire. The horn should sound.

- If the horn sounds, go to step 7.

- If the horn does not sound, go to step 4.

4. Remove the jumper wire from the dashboard wire harness 20P connector.

5. Check for continuity between dashboard wire harness 20P connector terminal No. 2 and body ground. There should be continuity.

- If there is continuity, go to step 6.

- If there is no continuity, repair an open or high resistance in the wire, or poor ground (G501).

6. Measure the voltage between dashboard wire harness 20P connector terminal No. 1 and body ground. There should be battery voltage.

- If there is battery voltage, check these items:
- Faulty horn.

- If there is no battery voltage, check for continuity between the cable reel and the under-dash fuse relay box.

7. Reconnect dashboard wire harness 20P connector to the cable reel, then remove the driver's airbag assembly Driver's Airbag Replacement.

8. Connect cable reel subharness 20P connector terminals No. 11 and No. 12 with a jumper wire. The horn should sound.

- If the horn sounds, go to step 9.

- If the horn does not sound, replace the cable reel Service and Repair.

9. Disconnect the cable reel subharness 20P connector (A).






10. Check for continuity between ground terminal (G551) and cable reel subharness 20P connector terminal No. 12. There should be continuity.

- If there is continuity, go to step 11.
- If there is no continuity, check for:
- An open or high resistance in the wire, replace the cable reel subharness.





11. Check for continuity between cable reel subharness 20P connector terminal No. 11 and horn switch positive terminal 1P. There should be continuity.

- If there is continuity, check or adjust the installation of the driver's airbag and the horn switch plate or replace the driver's airbag assembly.

- If there is no continuity, repair an open in the wire, or replace the cable reel subharness Overhaul.