LIGHTING SYSTEM Rear Fog Light Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the rear fog lights via the engine room junction block assembly.

CAUTION / NOTICE / HINT

PROCEDURE

1. Click here

   CHECK OPERATION (TAILLIGHTS)

   
   

   1. Check the operation of the taillights.

      OK
      Taillights operate normally.

   
   
   • OKClick here
   • NG

     GO TO PROBLEM SYMPTOMS TABLE (Click here)

2. Click here

   PERFORM ACTIVE TEST USING GTS

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power switch on (IG).

   3. Turn the GTS on.

   4. Enter the following menus: Body Electrical / Main Body / Active Test.

   5. Check that the relay operates.

      Table 1. Main Body

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

      OK
      Rear fog light relay operates. (Rear fog lights come on.)

   
   
   • OK

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

   • NGClick here
3. Click here

   CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY

   
   

   1. Using a voltmeter, check the signal reading of the engine room junction block assembly (Click here).

      OK
      Output signal reading is normal.

   
   
   • OKClick here
   • NG

     INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (RESULTS OF SIGNAL READING CHECK) (Click here)

4. Click here

   CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY POWER SOURCE AND BODY GROUND)

   
   
   1. 

      Remove the engine room junction block assembly from the engine room relay block and junction block assembly (Click here).

      Table 2. Text in Illustration

      *a

      Component without engine room junction block assembly connected (Engine Room Relay Block and Junction Block Assembly)

      -

      -

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

      Standard Voltage
      Tester Connection Condition Specified Condition A-1 (BATT) - Body ground Power switch off 11 to 14 V B-1 (ALT) - Body ground Power switch off 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition 1F-3 (GND1) - Body ground Always Below 1 Ω 1G-4 (GND2) - Body ground Always Below 1 Ω

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

5. Click here

   CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)

   
   

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition 1G-2 (TAIL) - 3D-9 Always Below 1 Ω 3D-9 - Body ground Always 10 kΩ or higher 1F-10 (RFGS) - 3D-35 Always Below 1 Ω 3D-35 - Body ground Always 10 kΩ or higher

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

6. Click here

   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.

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

      Standard Resistance
      Tester Connection Condition Specified Condition MB-27 (RFGO) - 3D-35 Always Below 1 Ω 3D-35 - Body ground Always 10 kΩ or higher

   4. Connect a positive (+) lead from the auxiliary battery to terminal 3E-1.

   5. Connect a negative (-) lead from the auxiliary battery to terminal MB-14 (TRLY).

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

      Standard Voltage
      Tester Connection Condition Specified Condition 3D-9 - Body ground Always 11 to 14 V

      Table 3. Text in Illustration

      *a	Component without harness connected (Instrument Panel Junction Block Assembly)

   
   
   • OKClick here
   • NG

     REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (Click here)

7. Click here

   CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - REAR LIGHT ASSEMBLY)

   
   

   1. Disconnect the 1F engine room junction block assembly connector.

   2. Disconnect the U7 rear light assembly LH connector.

   3. Disconnect the U1 rear light assembly RH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition 1F-12 (RFOG) - U7-3 Always Below 1 Ω 1F-12 (RFOG) - U1-3 Always Below 1 Ω

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

8. Click here

   CHECK HARNESS AND CONNECTOR (REAR LIGHT ASSEMBLY - BODY GROUND)

   
   

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

      Standard Resistance
      Tester Connection Condition Specified Condition U7-4 - Body ground Always Below 1 Ω U1-4 - Body ground Always Below 1 Ω

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

9. Click here

   CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY

   
   

   1. Replace the engine room junction block assembly with a new or known good one (Click here).

   2. Check that the fog lights operate normally.

      OK
      The fog lights operate normally.

   
   
   • OK

     END (ENGINE ROOM JUNCTION BLOCK ASSEMBLY WAS DEFECTIVE)

   • NG

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