Diagnostics Item 1 (4F21-28)

4F21 : SELECT HORN SIGNAL OPERATION.
Keep both LOCK/ARM and UNLOCK/DISARM buttons pressed for more than 1.5 seconds.

CHECK: Does the horn chirp one time ?

YES: Go to step 4F22.

NO: Replace keyless entry control module.

4F22: CHECK HORN SIGNAL OUTPUT SIGNAL.
1. Disconnect connector from keyless entry control module.




2. Measure voltage between keyless entry control module connector (B176) and chassis ground.

CHECK: Is the voltage more than 10 V ?

YES: Go to step 4F23.

NO: Go to step 4F26.

4F23: CHECK HORN RELAY.
1. Remove horn relay from main fuse box.




2. Check continuity between horn relay terminals.

CHECK: Does continuity exist ?

YES: Replace horn relay.

NO: Go to step 4F24.

4F24: CHECK HORN RELAY.




Check continuity between horn relay terminals.

CHECK: Does continuity exist ?

YES: Go to step 4F25.

NO: Replace horn relay.

4F25: CHECK HORN RELAY.
1. Connect the battery to horn relay terminals No.3 and No.4.




2. Check continuity between horn relay terminals.

CHECK: Does continuity exist ?

YES: Repair wiring harness of horn circuit.

NO: Replace horn relay.

4F26: CHECK FUSE.
Remove and visually check the fuse No.6 (in main fuse box).

CHECK: Is the fuse No.6 blown ?

YES: Replace fuse (15 A).

NO: Go to step 4F27.

4F27: CHECK POWER SUPPLY FOR HORN RELAY.
1. Install horn relay to main fuse box.




2. Measure voltage between main fuse box connector (F37) and chassis ground.

CHECK: Is the voltage more than 10 V ?

YES: Go to step 4F28.

NO: Repair wiring harness between main fuse box and battery.

4F28: CHECK RESISTANCE BETWEEN HORN RELAY AND KEYLESS ENTRY CONTROL MODULE.
1. Disconnect connector from main fuse box and keyless entry control module.




2. Measure resistance between keyless entry control module connector (B176) and main fuse box connector (F37).

CHECK: Is the resistance less than 10 ohms ?

YES: Replace keyless entry control module.

NO: Repair wiring harness between main fuse box and keyless entry control module.