Security Horn Circuit

THEFT DETERRENT / KEYLESS ENTRY: THEFT DETERRENT SYSTEM: Security Horn Circuit
- Security Horn Circuit

DESCRIPTION

When the theft deterrent system is switched from the armed state to the alarm sounding state, the main body ECU (multiplex network body ECU) controls the security horn.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Select the item below in the Active Test and then check that the security horn assembly operates.

Main Body (Main Body ECU (Multiplex Network Body ECU))





OK:

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

NG -- INSPECT SECURITY HORN ASSEMBLY

OK -- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Removal

2. INSPECT SECURITY HORN ASSEMBLY

(a) Remove the security horn assembly Removal.





(b) Check the operation of the security horn assembly.

OK:





NG -- REPLACE SECURITY HORN ASSEMBLY Removal
OK -- Continue to next step.

3. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Disconnect the 2C instrument panel junction block assembly and A main body ECU (multiplex network body ECU) connectors.





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

Standard Resistance:





Text in Illustration





NG -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
OK -- Continue to next step.

4. INSPECT S-HORN RELAY

(a) Remove the S-HORN relay from the engine room relay block.





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

Standard Resistance:





NG -- REPLACE S-HORN RELAY
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (S-HORN RELAY POWER SOURCE)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

6. CHECK HARNESS AND CONNECTOR (S-HORN RELAY - INSTRUMENT PANEL JUNCTION BLOCK)

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (SECURITY HORN ASSEMBLY - S-HORN RELAY)

(a) Disconnect the A48 security horn assembly connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Removal