Horn Circuit (2016)

Horn Circuit Troubleshooting 

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

1. Problem verification

   -1. Push the horn switch.

   Does the horn sound?

   YES 

   Intermittent failure, the system is OK at this time. Check for loose or poor connections.

   NO 

   Go to step 2.

2. Fuse check

   -1. Check the following fuse.

   Fuse	No. A18 (10 A)
   Location	Under-hood fuse/relay box

   Is the fuse OK?

   YES 

   Go to step 3.

   NO 

   Replace the fuse, and recheck. If the fuse blows again, repair a short in the No. A18 (10 A) fuse circuit.

3. Horn relay check

   -1. Remove the horn relay from the under-dash relay holder C, and test it .

   Is the relay OK?

   YES 

   Go to step 4.

   NO 

   Replace the horn relay, then recheck.

4. Open wire check (+B HORN line)

   -1. Measure the voltage between test points 1 and 2.

   Test condition	OFF modeHorn relay: disconnected
   Test circuit	+B HORN
   Test point 1	Horn relay 4P socket No. 1 (WHT)
   Test point 2	Body ground

   Test point 1	Horn relay 4P socket No. 3 (WHT)
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there battery voltage?

   YES 

   The +B HORN wire is OK. Go to step 5.

   NO 

   Repair an open or high resistance in the wire.

5. Determine possible failure area (horn relay switch side circuit, horn relay coil side circuit)

   -1. Connect terminals A and B with a jumper wire.

   -2. Connect terminals A and B with a jumper wire.

   Terminal A	Horn relay 4P socket No. 1 (WHT)
   Terminal B	Horn relay 4P socket No. 2 (LT GRN)

   Courtesy of HONDA, U.S.A., INC.

   Does the horn sound?

   YES 

   Go to step 6.

   NO 

   Go to step 11.

6. Open wire check (HORN RLY CL- line)

   -1. Disconnect the jumper wire.

   -2. Reinstall the horn relay.

   -3. Measure the voltage between test points 1 and 2.

   Test condition	OFF mode
   Test circuit	HORN RLY CL-
   Test point 1	Under-dash fuse/relay box connector C (38P) No. 37 (PNK)
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there battery voltage?

   YES 

   The HORN RLY CL- wire is OK. Go to step 7.

   NO 

   Repair an open or high resistance in the wire.

7. Determine possible failure area (HORN SW line, MICU)

   -1. Measure the voltage between test points 1 and 2.

   Test condition	OFF mode
   Test circuit	HORN SW
   Test point 1	Under-dash fuse/relay box connector Q (16P) No. 10 (TAN)
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there battery voltage?

   YES 

   Go to step 8.

   NO 

   Faulty MICU; replace the under-dash fuse/relay box .

8. Open wire check (HORN SW line) 1

   -1. Remove the driver's airbag assembly .

   -2. Measure the voltage between test points 1 and 2.

   Test condition	OFF mode
   Test circuit	HORN SW
   Test point 1	Cable reel connector A (20P) No. 10 (TAN)
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there battery voltage?

   YES 

   Go to step 9.

   NO 

   Repair an open or high resistance in the wire.

9. Cable reel check

   -1. Measure the voltage between test points 1 and 2.

   Test condition	OFF mode
   Test circuit	HORN SW
   Test point 1	Cable reel connector C (20P) No. 1 (ORN)
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there battery voltage?

   YES 

   Go to step 10.

   NO 

   Replace the cable reel .

10. Open wire check (HORN SW line) 2

    -1. Measure the voltage between test points 1 and 2.

    Test condition	OFF mode
    Test circuit	HORN SW
    Test point 1	Horn switch 1P connector No. 1 (ORN)
    Test point 2	Body ground

    Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Check the installation of the driver's airbag assembly and the steering wheel. If the horn switch plate is OK, replace the driver's airbag assembly .

    NO 

    Repair an open or high resistance in the wire.

11. Open wire check (HORN RLY OUT line)

    -1. Measure the voltage between test points 1 and 2.

    Test condition	OFF modeHorn relay: disconnectedHorn relay 4P socket No. 1 (WHT) and No. 2 (LT GRN): jumped
    Test circuit	HORN RLY OUT
    Test point 1	Horn (LOW)/(HIGH) 1P connector No. 1 (LT GRN)
    Test point 2	Body ground

    Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    Remove the horn, and test it . If the horn is OK, check the horn ground.

    NO 

    Repair an open or high resistance in the wire.