Horn Circuit

THEFT DETERRENT: TOYOTA VEHICLE INTRUSION PROTECTION SYSTEM: Horn Circuit

Horn Circuit

DESCRIPTION

When the TVIP system changes from the armed state to the alarm sounding state, the TVIP ECU turns on the HORN relay so that it can standard the horns. The horn cycles between cycles between ON and OFF at intervals of 0.4 seconds.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT LOW PITCHED HORN ASSEMBLY





(a) Connect the battery's positive (+) lead to the terminal, and the negative (-) lead to the horn body.
(b) Check that the horn sounds.
Standard:
Horn sounds
NG -- REPLACE LOW PITCHED HORN ASSEMBLY
OK -- Continue to next step.
2. INSPECT HORN RELAY





(a) Remove the HORN relay from the engine room R/B.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPLACE HORN RELAY
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (TVIP ECU - ENGINE ROOM R/B)





(a) Remove the HORN relay from the engine room R/B.
(b) Disconnect the T3 TVIP ECU connector.
(c) 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.
4. CHECK HARNESS AND CONNECTOR (ENGINE ROOM R/B AND J/B - HORN)





(a) Remove the HORN relay from the engine room R/B.
(b) Disconnect the HORN connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE TVIP ECU