LIGHTING SYSTEM Headlight (HI-BEAM) Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) receives headlight dimmer switch information signals and illuminates the high beam headlights.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. PERFORM ACTIVE TEST USING GTS (HEADLIGHT)

   
   

   1. Using the GTS, perform the Active Test.

      Click here

      
      Body Electrical > Main Body > Active Test

      Tester Display	Measurement Item	Control Range	Diagnostic Note
      Head Light Hi	Headlight dimmer relay	ON or OFF	-

      
      Body Electrical > Main Body > Active Test

      Tester Display
      Head Light Hi

      Result
      Proceed to High beam headlights come on High beam headlights do not come on

   
   

   High beam headlights come on

   REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for LHD: REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for RHD: REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

   High beam headlights do not come on

2. INSPECT HEADLIGHT DIMMER RELAY (DIMMER)

   
   

   1. 

      Remove the headlight dimmer relay from the No. 1 engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition 3 - 5 Battery voltage applied between terminals 1 and 2 Below 1 Ω 3 - 5 Battery voltage not applied between terminals 1 and 2 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE HEADLIGHT DIMMER RELAY (DIMMER)

   OK

3. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER RELAY [DIMMER] - BATTERY)

   
   
   1. 

      *a	Front view of wire harness connector (to Headlight Dimmer Relay)

      Remove the headlight dimmer relay from the No. 1 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 Headlight dimmer relay terminal 3 - Body ground Always 11 to 14 V Headlight dimmer relay terminal 2 - Body ground

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

4. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER RELAY [DIMMER] - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

   
   

   1. Remove the headlight dimmer relay from the No. 1 engine room relay block and junction block assembly.

   2. Disconnect the 3B instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition Headlight dimmer relay terminal 1 - 3B-54 Always Below 1 Ω 3B-54 - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

5. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

   
   
   1. 

      *1

      DIM

      Remove the instrument panel junction block assembly.

      for LHD:

      Click here

      for RHD:

      Click here

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

      for LHD:

      Click here

      for RHD:

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition A-22 (DIM) - 3B-54 Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   OK

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

   NG

   REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY for LHD: REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY for RHD: REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here