Security Horn Circuit

THEFT DETERRENT: THEFT DETERRENT SYSTEM: Security Horn Circuit

Security Horn Circuit

DESCRIPTION

When the theft deterrent system is changed from the armed state to the alarm sounding state, the theft warning ECU can sound the security horn. The horn cycles between ON and OFF at intervals of approximately 0.4 seconds.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (SECURITY HORN)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the tester main switch ON.
(d) Select the item below in the Active Test and then check that the horn operate.
Theft Warning ECU:






OK:
Security horn operates normally.
NG -- INSPECT FUSE (ECU-B)
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
2. INSPECT FUSE (ECU-B)




(a) Remove the ECU-B fuse from the engine room R/B.
(b) Measure the resistance.
Standard resistance:
Below 1 Ohms
(c) Reinstall the ECU-B fuse.
NG -- REPLACE FUSE
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (THEFT WARNING ECU ASSEMBLY- BODY GROUND)




(a) Disconnect the D26 theft warning ECU connector.
(b) Measure the voltage.
Standard voltage:





(c) Reconnect the theft warning ECU connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. INSPECT SECURITY HORN ASSEMBLY




(a) Disconnect the A23 security horn connector.
(b) Check the operation of the security horn.
Standard:





(c) Reconnect the security horn connector.
NG -- REPLACE SECURITY HORN ASSEMBLY
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (THEFT WARNING ECU ASSEMBLY - SECURITY HORN ASSEMBLY)
(a) Disconnect the D26 theft warning ECU and the A23 security horn connectors.




(b) Measure the resistance.
Standard resistance:





(c) Reconnect the theft warning ECU and the security horn connectors.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE THEFT WARNING ECU ASSEMBLY