Front Fog Light Circuit: Procedure

1. Connect Techstream to the DLC3.
2. Turn the ignition switch on (IG).
3. Turn Techstream on.
4. Select the following menu items: Body Electrical / Main Body / Active Test.
5. Check that the relay operates.
   MAIN BODY:
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Front Fog Light Relay	Front fog light relay	ON/OFF	-

   OK

   Front fog light relay operates. (Front fog lights come on.)

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

NG: Go to next step 

1. Remove the FR FOG fuse from the instrument panel J/B assembly.
2. Measure the resistance of the fuse.

   Standard resistance

   Below 1 Ω

NG → REPLACE FUSE 

OK: Go to next step 

1. Remove the front fog light relay from the instrument panel J/B assembly.
   Fig 1: Identifying Fog Light Relay Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

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

NG → REPLACE FOG LIGHT RELAY 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 2: Identifying Instrument Panel Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard voltage

   Tester Connection	Condition	Specified Condition
   IC-1 - Body ground	Light control switch in HEAD, front fog light switch OFF → ON	Below 1 V → 10 to 14 V
   ID-5 - Body ground	Light control switch in HEAD, front fog light switch OFF → ON	Below 1 V → 10 to 14 V

OK → REPAIR OR REPLACE HARNESS OR CONNECTOR (INSTRUMENT PANEL J/B ASSEMBLY - BODY GROUND) 

NG: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 3: Identifying Instrument Panel J/B Assembly Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard voltage

   Tester Connection	Condition	Specified Condition
   IL-3 - Body ground	Light control switch OFF → TAIL	Below 1 V → 10 to 14 V

NG → REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 4: Identifying Instrument Panel J/B Assembly Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard voltage

   Tester Connection	Condition	Specified Condition
   IL-4 - Body ground	Light control switch OFF → TAIL	Below 1 V → 10 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the II instrument panel J/B assembly connector.
   Fig 5: Identifying II Instrument Panel J/B Assembly Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   II-8 - Body ground	Light control switch OFF → TAIL	Below 1 V → 10 to 14 V

NG → REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY 

OK: Go to next step 

1. Disconnect the E7 main body ECU connector.
   Fig 6: Checking Harness And Connector (Body ECU -- Instrument Panel Junction Block Assembly)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   E7-4 - II-8	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY