Lighting System - Headlight Signal Circuit
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - COMBINATION SWITCH ASSEMBLY)
CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - COMBINATION SWITCH)
CHECK HARNESS AND CONNECTOR (COMBINATION SWITCH ASSEMBLY - BODY GROUND)
CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - COMBINATION SWITCH)
LIGHTING SYSTEM - Headlight Signal Circuit
DESCRIPTION
The main body ECU RH receives a HEAD position signal from the combination switch as a backup link. It also receives a signal from the combination switch via the multiplex communication system.
If this link is grounded, the headlights will illuminate.
WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - COMBINATION SWITCH ASSEMBLY) |
Disconnect the J26 combination switch connector.
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
| Tester Connection | Condition | Specified Condition |
| J26-4 (HEAD) - Body ground | Always | 10 to 14 V |
| 2.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - COMBINATION SWITCH) |
Connect the J26 combination switch connector.
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
| Tester Connection | Condition | Specified Condition |
| J26-4 (HEAD) - Body ground | Light control switch is off | 10 to 14 V |
| J26-4 (HEAD) - Body ground | Light control switch is in HEAD position | Below 1 V |
| OK | |
| |
| PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
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| 3.CHECK HARNESS AND CONNECTOR (COMBINATION SWITCH ASSEMBLY - BODY GROUND) |
Disconnect the J26 combination switch connector.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
| Tester Connection | Condition | Specified Condition |
| J26-5 (E) - Body ground | Always | Below 1 Ω |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| OK | |
| |
| REPLACE WINDSHIELD WIPER SWITCH ASSEMBLY |
|
| 4.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - COMBINATION SWITCH) |
Disconnect the J74 ECU connector.
Disconnect the J26 combination switch connector.
Measure the resistance according to the value(s) in the table below.
- Standard resistance:
| Tester Connection | Condition | Specified Condition |
| J74-23 (HEAD) - J26-4 (HEAD) | Always | Below 1 Ω |
| J74-23 (HEAD) - Body ground | Always | 10 kΩ or higher |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| OK | |
| |
| REPLACE MAIN BODY ECU RH (COWL SIDE J/B RH) |
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