DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
INSPECT SECURITY HORN ASSEMBLY
CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH (COWL SIDE J/B RH) - SECURITY HORN ASSEMBLY)
THEFT DETERRENT SYSTEM (w/ Intrusion Sensor) - Security Horn Circuit
DESCRIPTION
When the theft deterrent system is operating, the relay in the main body ECU RH turns on and off, causing the security horn to sound.
WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.INSPECT SECURITY HORN ASSEMBLY |
Remove the security horn assembly.
Check operation of the horn.
- Standard:
| Measurement Condition | Specified Condition |
| Battery positive (+) → Terminal 1 | Horn sounds |
| Battery negative (-) → Horn body |
| | REPAIR OR REPLACE SECURITY HORN ASSEMBLY |
|
|
| 2.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH (COWL SIDE J/B RH) - SECURITY HORN ASSEMBLY) |
Disconnect the A36 ECU connector and the A37 horn connector.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
| Symbol (Terminal Connection) | Specified Condition |
| SH (A36-1) - (A37-1) | Below 1 Ω |
| SH (A36-1) or (A37-1) - Body ground | 10 kΩ or higher |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| OK | |
| |
| PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
|
LEXUS IS250, IS220d / GSE20 ALE20
