LIGHTING SYSTEM Front Fog Light Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) receives headlight dimmer switch information signals, and illuminates the front fog light.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (FRONT FOG LIGHT RELAY)

   
   

   1. Using the intelligent tester, perform the Active Test Click here.

      Main Body

      Tester Display	Test Part	Control Range	Diagnostic Note
      Front Fog Light Relay	Front fog light relay	ON/OFF	Light control switch is in TAIL position

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

      Result
      Result Proceed to NG A OK B

   
   

   B

   REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

   A

2. VEHICLE CONDITION

   
   

   1. Check the vehicle specifications.

      Result
      Result Proceed to w/ Rear Fog Light A w/o Rear Fog Light B

   
   

   B

   INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

   A

3. INSPECT FRONT FOG LIGHT RELAY (FR FOG)

   
   

   1. Remove the front fog light relay from the No. 5 relay block.

   2. Inspect the front fog light relay Click here.

   
   

   NG

   REPLACE FRONT FOG LIGHT RELAY (FR FOG)

   OK

4. CHECK HARNESS AND CONNECTOR (BATTERY - INSTRUMENT PANEL JUNCTION BLOCK)

   
   

   1. Disconnect the 3E*1 or 3F*2 instrument panel junction block assembly connector.

      
      

      • *1: for LHD

      • *2: for RHD

   2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      for LHD
      Tester Connection Condition Specified Condition 3E-1 - Body ground Always 11 to 14 V
      for RHD
      Tester Connection Condition Specified Condition 3F-1 - Body ground Always 11 to 14 V

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

5. CHECK HARNESS AND CONNECTOR (FRONT FOG LIGHT RELAY - INSTRUMENT PANEL JUNCTION BLOCK)

   
   

   1. Disconnect the 3A instrument panel junction block assembly connector.

   2. Measure the resistance according to the value(s) in the table below.

      

      Text in Illustration

      *a

      No. 5 Relay Block (FR FOG Relay Terminal)

      *b

      Front view of wire harness connector (to Instrument Panel Junction Block Assembly)

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition Relay terminal 1 - 3A-15 Always Below 1 Ω Relay terminal 2 - 3A-55 Always Below 1 Ω Relay terminal 5 - 3A-4 Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition 3A-15 - Body ground Always 10 kΩ or higher 3A-55 - Body ground Always 10 kΩ or higher 3A-4 - Body ground Always 10 kΩ or higher

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

6. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

   
   

   1. Remove the instrument panel junction block assembly Click here.

   2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

      

      Text in Illustration

      *A	for LHD	*B	for RHD
      *a	Component without harness connected (Instrument Panel Junction Block Assembly)	-	-

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition 3A-15 - MB-13 (FFGO) Always Below 1 Ω 3E-1 - 3A-4 Always Below 1 Ω 3E-1 - 3A-55 Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition 3A-15 - MB-13 (FFGO) Always Below 1 Ω 3F-1 - 3A-4 Always Below 1 Ω 3F-1 - 3A-55 Always 10 kΩ or higher

   4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      for LHD
      Tester Connection Condition Specified Condition 3A-55 - Battery negative (-) terminal Connect a positive (+) lead from the battery → 3E-1 Connect a negative (-) lead from the battery → MB-14 (TRLY) 11 to 14 V Not connect a positive (+) lead from the battery → 3E-1 Not connect a negative (-) lead from the battery → MB-14 (TRLY) Below 1 V
      for RHD
      Tester Connection Condition Specified Condition 3A-55 - Battery negative (-) terminal Connect a positive (+) lead from the battery → 3F-1 Connect a negative (-) lead from the battery → MB-14 (TRLY) 11 to 14 V Not connect a positive (+) lead from the battery → 3F-1 Not connect a negative (-) lead from the battery → MB-14 (TRLY) Below 1 V

   
   

   OK

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

   NG

   REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

7. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

   
   

   1. Remove the instrument panel junction block assembly Click here.

   2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

      

      Text in Illustration

      *a

      Component without harness connected (Instrument Panel Junction Block Assembly)

      -

      -

   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition 3F-1 - 3C-7 Always 10 kΩ or higher

   4. Measure the voltage according to the value(s) in the table below.

      Standard voltage
      Tester Connection Condition Specified Condition MB-13 (FFGO) - Body ground Connect the positive (+) battery lead to 3F-1 and the negative (-) battery lead to MB-14 (TRLY) 11 to 14 V 3C-7 - Body ground Connect the positive (+) battery lead to 3F-1 and the negative (-) battery lead to MB-13 (FFGO) and MB-14 (TRLY) 11 to 14 V

   
   

   OK

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

   NG

   REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here