Security Horn Circuit

THEFT DETERRENT / KEYLESS ENTRY: THEFT DETERRENT SYSTEM (w/o Smart Key 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 (driver side junction block assembly) controls the security horn.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Select the item below in the Active Test and then check that the security horn assembly operates.

Body





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

NG -- INSPECT SECURITY HORN ASSEMBLY
OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE
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
OK -- Continue to next step.

3. INSPECT SEC HORN RELAY




(a) Remove the SEC 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 SEC HORN RELAY
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (SEC HORN RELAY POWER SOURCE)




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





Text in Illustration





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

5. CHECK HARNESS AND CONNECTOR (SEC HORN RELAY - MAIN BODY ECU)




(a) Disconnect the D51 main body ECU (driver side junction block assembly) connector.
(b) Measure the resistance on the relay block side according to the value(s) in the table below.
Standard Resistance:





Text in Illustration





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

6. CHECK HARNESS AND CONNECTOR (SEC HORN RELAY POWER SOURCE)




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





Text in Illustration





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

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




(a) Disconnect the A23 security horn assembly connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY)