Theft Deterrent System Horn Circuit


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HORN ASSEMBLY

CHECK WIRE HARNESS (THEFT WARNING ECU - INTEGRATION RELAY (HORN RELAY))

THEFT DETERRENT SYSTEM - Horn Circuit


DESCRIPTION

When the theft deterrent system is changed from the armed state to the alarm sounding state, the ECU turns on the HORN relay, causing the vehicle horn to sound at 0.4 second intervals.

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Theft Deterrent.Theft Deterrent System.Theft Deterrent System Horn Circuit


INSPECTION PROCEDURE

1.CHECK HORN ASSEMBLY

  1. Press the horn switch and check if the horn sounds.

    Result:
    Result
    		Proceed to
    Horn sounds
    		A
    Horn does not sound
    		B


B
GO TO HORN SYSTEM
A


2.CHECK WIRE HARNESS (THEFT WARNING ECU - INTEGRATION RELAY (HORN RELAY))
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Theft Deterrent.Theft Deterrent System.Theft Deterrent System Horn Circuit

  1. Disconnect the T16 ECU connector.

  1. Disconnect the 1I integration relay connector.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    T16-24 (HORN) - 1I-7
    		Below 1 Ω
    T16-24 (HORN) - Body ground
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

REPLACE THEFT WARNING ECU