Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.

PERFORM ACTIVE TEST USING TECHSTREAM

Connect the Techstream to the DLC3.
Turn the engine switch on (IG)
Turn the Techstream on

Select the item below in the Active Test and then check that the security horn operates.

Body

DIAGNOSTIC NOTE

Tester Display	Test Part	Control Range	Diagnostic Note
Security Horn	Security horn	ON/OFF	-

OK: The security horn sounds and stops correctly when operated through the Techstream.

NG: Go to step 2

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (See PROBLEM SYMPTOMS TABLE )

INSPECT SECURITY HORN ASSEMBLY

Remove the security horn assembly (See REMOVAL )

Check operation of the horn.

Standard

MEASUREMENT SPECIFIED CONDITION CHART

Measurement Condition	Specified Condition
Battery positive (+) → Terminal 1	Horn sounds
Battery negative (-) → Horn body	Horn sounds

Fig 1: Checking Operation Of Horn

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE SECURITY HORN ASSEMBLY (See REMOVAL )

OK: Go to next Step

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH (COWL SIDE J/B RH) SECURITY HORN ASSEMBLY)

Disconnect the A36 cowl side junction block RH connector and the A37 security horn connector.

Measure the resistance according to the value (s) in the table below

Standard Resistance

RESISTANCE REFERENCE

Terminal Connection	Condition	Specified Condition
A36-1 (SH) - A37-1	Always	Below 1 Ω
A36-1 (SH) - Body ground	Always	10 kΩ or higher
A37-1 Body ground	Always	10 kΩ or higher

Fig 2: Identifying A36 Cowl Side Junction Block RH Connector And A37 Security Horn Connector

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (See PROBLEM SYMPTOMS TABLE )