Front Fog Light Circuit: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Body / Active Test.
5. Check the operation.
   BODY (BODY ECU)
   
   

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

   OK

   Front fog lights come on.

NG → See step   2 

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

1. Inspect front fog relay continuity.
   Fig 1: Identifying Front Fog Relay Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Remove the front fog relay from the instrument panel J/B.
   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
      3 - 5	Below 1 Ω (When battery voltage is applied to terminal 1- 2)

2. Inspect TAIL relay continuity.
   Fig 2: Identifying Tail Relay Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Remove the tail relay from the instrument panel J/B.
   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
      3 - 5	Below 1 Ω (When battery voltage is applied to terminal 1- 2)
      3 - 4	Below 1 Ω (When battery voltage is applied to terminal 1- 2)

NG → REPLACE RELAY 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 3: Identifying 1A Instrument Panel Junction Block Assembly Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard voltage

   Tester Connection	Condition	Specified Condition
   IA-1 - Body ground	Always	10 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 4: Identifying 1C and 1D Instrument Panel Junction Block Assembly Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard voltage

   Tester Connection	Condition	Specified Condition
   IC-1 - Body ground	Light control switch TAIL and Front fog light switch OFF → ON	Below 1 V → 10 to 14 V
   ID-5 - Body ground	Light control switch TAIL and Front fog light switch OFF → ON	Below 1 V → 10 to 14 V

NG → See step   5 

OK → REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Measure the voltage according to the value(s) in the table below.
   Fig 5: Identifying 1L Instrument Panel Junction Block Assembly Connector Terminals

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

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 6: Identifying 1L Instrument Panel Junction Block Assembly Connector Terminals

   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 D9 connector of the multiplex network body ECU and the II connector of the instrument panel junction block assembly.
2. Measure the resistance according to the value(s) in the table below.
   Fig 7: Identifying (D9) Body ECU and (11) Instrument Panel Junction Block Assembly Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance

   Tester Connection	Condition	Specified Condition
   D9-7 - II-8	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

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