Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

PERFORM ACTIVE TEST BY INTELLIGENT TESTER (FRONT FOG LIGHT RELAY)

Select the ACTIVE TEST, use the intelligent tester (with CAN VIM) to generate a control command, and then check that the front fog light relay operates.

Front light ECU (Front controller)

ACTIVE TEST DETAIL - FRONT LIGHT ECU (FRONT CONTROLLER)

Item	Test Details	Diagnostic Note
F FOG LIGHT RLY	Front fog light relay ON / OFF	-

OK: Fog light illuminates.

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

NG: Go to Next step

INSPECT FRONT FOG LIGHT ASSEMBLY

Fig 1: Identifying Front Fog Light Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Remove the front fog light.

Apply battery voltage to the front fog light connector and check that the front fog light illuminates.

MEASUREMENT CONDITION AND SPECIFIED CONDITION

Measurement Condition	Specified Condition
Battery positive (+) → Terminal 2 Battery negative (-) → Terminal 1	Front fog light illuminates

NG: REPLACE FRONT FOG LIGHT ASSEMBLY

OK: Go to Next step

INSPECT RELAY (Marking: FR FOG)

Fig 2: Identifying FR FOG Relay Connector Terminals

Remove the FR FOG relay from the engine room No. 2 relay block.

Measure the resistance of the relay.

Standard resistance

RESISTANCE SPECIFICATION

Tester Connection	Specified Condition
3 - 5	10 kΩ or higher
3 - 5	Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

NG: REPLACE RELAY

OK: Go to Next step

CHECK WIRE HARNESS (ECU - BODY GROUND)
1. Remove the front light ECU from the relay block.
  
  Fig 3: Identifying Front Fog Light ECU Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a service wire, connect the front light ECU terminal 16 (FFOG-RLY) of the engine room No. 2 relay block on the wire harness side and body ground.
3. Check that the front fog light illuminates.
  OK: Front fog light illuminates.
NG: REPAIR OR REPLACE HARNESS AND CONNECTOR

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE