DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
PERFORM ACTIVE TEST BY INTELLIGENT TESTER
INSPECT FUSE (RR FOG)
CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - BATTERY)
CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - BODY GROUND)
LIGHTING SYSTEM - Rear Fog Light Circuit
DESCRIPTION
The main body ECU LH receives rear fog light switch information from the combination switch, and turns on the rear fog lights.
WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.PERFORM ACTIVE TEST BY INTELLIGENT TESTER |
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Turn the intelligent tester main switch on.
Select the item below in the Active Test and then check the rear fog light operation.
ACTIVE TEST: Body No. 3 (Main Body ECU LH)| Item | Test Details | Diagnostic Note |
| Rear fog light |
Rear fog light ON / OFF | - |
- OK:
- Rear fog lights illuminate.
| OK | |
| |
| PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE |
|
Remove the RR FOG fuse from the No. 1 junction block.
Measure the resistance of the fuse.
- Standard resistance:
- Below 1 Ω
| 3.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - BATTERY) |
Disconnect the LM junction block connector.
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
| Tester Connection | Condition | Specified Condition |
| LM-1 (RFRL) - Body ground | Always | 10 to 14 V |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| 4.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - BODY GROUND) |
Disconnect the LJ junction block connector.
Measure the voltage according to the value(s) in the table below.
- Standard voltage:
| Tester Connection | Condition | Specified Condition |
| LJ-25 - Body ground | Light control switch HEAD and rear fog light switch ON | 10 to 14 V |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| NG | |
| |
| REPLACE MAIN BODY ECU LH (COWL SIDE J/B LH) |
|
LEXUS IS250, IS220d / GSE20 ALE20
