LIGHTING SYSTEM Headlight Dimmer Switch Circuit

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DESCRIPTION

The main body ECU (multiplex network body ECU) receives the following switch information:

• Light control switch in off*1, tail, head or AUTO position

• Dimmer switch in high, low or high flash (pass) position

• Fog light switch in rear*2 or off position

• *1: w/ Light Control Switch Off Position

• *2: w/ Rear Fog Light

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WIRING DIAGRAM

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1. 

   for Light Control Switch LH Side Type

2. 

   for Light Control Switch RH Side Type

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CAUTION / NOTICE / HINT

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PROCEDURE

1. Click here

   READ VALUE USING GTS

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Enter the following menus: Body Electrical / Main Body / Data List.

   5. Read the Data List according to the display on the GTS.

      
      
      1. Body Electrical > Main Body > Data List

         Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
         Dimmer SW	Dimmer switch high position signal	ON or OFF	ON: Dimmer switch in high or high flash position OFF: Dimmer switch in low position	-
         Passing Light SW	Dimmer switch high flash position (pass) signal	ON or OFF	ON: Dimmer switch in high flash position OFF: Dimmer switch not in high flash position	-
         Rear Fog Light SW	Fog light switch rear position signal	ON or OFF	ON: Fog light switch in rear position OFF: Fog light switch off	*
         Auto Light SW	Light control switch AUTO position signal	ON or OFF	ON: Light control switch in AUTO position OFF: Light control switch not in AUTO position	-
         Head Light SW (Head)	Light control switch head position signal	ON or OFF	ON: Light control switch in head position OFF: Light control switch not in head position	-
         Head Light SW (Tail)	Light control switch tail position signal	ON or OFF	ON: Light control switch in tail or head position OFF: Light control switch not in tail or head position	-

      2. 
         
         10. 
             
         11. 
             
         12. 
             
         13. 
             
         14. 
             
         15. 
             
      
      

      • *: w/ Rear Fog Light

      
      
      1. Body Electrical > Main Body > Data List

         Tester Display
         Dimmer SW
         Passing Light SW
         Rear Fog Light SW
         Auto Light SW
         Head Light SW (Head)
         Head Light SW (Tail)

      2. 
         
         1. 
            
      3. 
         
         10. 
             
         11. 
             
         12. 
             
         13. 
             
         14. 
             
         15. 
             

      OK
      Normal conditions listed above are displayed.

      Result
      Proceed to OK NG

   
   
   • OK

     PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLEClick here

   • NGClick here
2. Click here

   INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY

   Tip:

   Inspect the items that did not change when reading the Data List.

   
   

   1. Remove the headlight dimmer switch assembly.

      Click here

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

      
      
      1. 

         *A	w/ Rear Fog Light
         *a	Component without harness connected (Headlight Dimmer Switch Assembly)

         for Light Control Switch LH Side Type:

         Standard Resistance
         Table 1. Light Control Switch Tester Connection Condition Specified Condition 22 (T) - 19 (EL) Light control switch off*1 10 kΩ or higher 23 (H) - 19 (EL) Light control switch off*1 10 kΩ or higher 24 (A) - 19 (EL) Light control switch off*1 10 kΩ or higher 22 (T) - 19 (EL) Light control switch in tail position Below 1 Ω 22 (T) - 19 (EL) Light control switch in head position Below 1 Ω 23 (H) - 19 (EL) Light control switch in head position Below 1 Ω 24 (A) - 19 (EL) Light control switch in AUTO position Below 1 Ω
         Table 2. Dimmer Switch Tester Connection Condition Specified Condition 18 (HU) - 19 (EL) Dimmer switch in high position Below 1 Ω 18 (HU) - 19 (EL) Dimmer switch in high flash position Below 1 Ω 21 (HF) - 19 (EL) Dimmer switch in high flash position Below 1 Ω
         Table 3. Fog Light Switch Tester Connection Condition Specified Condition 9 (B) - 10 (LFG)*2 Fog light switch off 10 kΩ or higher 9 (B) - 10 (LFG)*2 Fog light switch in rear position Below 1 Ω

         
         

         • *1: w/ Light Control Switch Off Position

         • *2: w/ Rear Fog Light

      2. 

         *A	w/ Rear Fog Light
         *a	Component without harness connected (Headlight Dimmer Switch Assembly)

         for Light Control Switch RH Side Type:

         Standard Resistance
         Table 4. Light Control Switch Tester Connection Condition Specified Condition 15 (T) - 18 (EL) Light control switch off*1 10 kΩ or higher 14 (H) - 18 (EL) Light control switch off*1 10 kΩ or higher 13 (A) - 18 (EL) Light control switch off*1 10 kΩ or higher 15 (T) - 18 (EL) Light control switch in tail position Below 1 Ω 15 (T) - 18 (EL) Light control switch in head position Below 1 Ω 14 (H) - 18 (EL) Light control switch in head position Below 1 Ω 13 (A) - 18 (EL) Light control switch in AUTO position Below 1 Ω
         Table 5. Dimmer Switch Tester Connection Condition Specified Condition 19 (HU) - 18 (EL) Dimmer switch in high position Below 1 Ω 19 (HU) - 18 (EL) Dimmer switch in high flash position Below 1 Ω 16 (HF) - 18 (EL) Dimmer switch in high flash position Below 1 Ω
         Table 6. Fog Light Switch Tester Connection Condition Specified Condition 4 (B) - 3 (LFG)*2 Fog light switch off 10 kΩ or higher 4 (B) - 3 (LFG)*2 Fog light switch in rear position Below 1 Ω

         
         

         • *1: w/ Light Control Switch Off Position

         • *2: w/ Rear Fog Light

      Result
      Proceed to OK NG

   
   
   • OKClick here
   • NG

     REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLYClick here

3. Click here

   CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH ASSEMBLY - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))

   
   

   1. Disconnect the O2 main body ECU (multiplex network body ECU) connector.

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

      
      

      1. for Light Control Switch LH Side Type:

         Standard Resistance

         Tester Connection Condition Specified Condition O22-9 (B) - O2-23 (RFOG)* Always Below 1 Ω O22-18 (HU) - O2-24 (HU) Always Below 1 Ω O22-21 (HF) - O2-10 (HF) Always Below 1 Ω O22-22 (T) - O2-22 (TAIL) Always Below 1 Ω O22-23 (H) - O2-12 (HEAD) Always Below 1 Ω O22-24 (A) - O2-8 (A) Always Below 1 Ω O22-9 (B) - Body ground* Always 10 kΩ or higher O22-18 (HU) - Body ground Always 10 kΩ or higher O22-21 (HF) - Body ground Always 10 kΩ or higher O22-22 (T) - Body ground Always 10 kΩ or higher O22-23 (H) - Body ground Always 10 kΩ or higher O22-24 (A) - Body ground Always 10 kΩ or higher O22-19 (EL) - Body ground Always Below 1 Ω O22-10 (LFG) - Body ground Always Below 1 Ω

         
         

         • *: w/ Rear Fog Light

      2. for Light Control Switch RH Side Type:

         Standard Resistance

         Tester Connection Condition Specified Condition O22-4 (B) - O2-23 (RFOG)* Always Below 1 Ω O22-19 (HU) - O2-24 (HU) Always Below 1 Ω O22-16 (HF) - O2-10 (HF) Always Below 1 Ω O22-15 (T) - O2-22 (TAIL) Always Below 1 Ω O22-14 (H) - O2-12 (HEAD) Always Below 1 Ω O22-13 (A) - O2-8 (A) Always Below 1 Ω O22-4 (B) - Body ground* Always 10 kΩ or higher O22-19 (HU) - Body ground Always 10 kΩ or higher O22-16 (HF) - Body ground Always 10 kΩ or higher O22-15 (T) - Body ground Always 10 kΩ or higher O22-14 (H) - Body ground Always 10 kΩ or higher O22-13 (A) - Body ground Always 10 kΩ or higher O22-18 (EL) - Body ground Always Below 1 Ω O22-3 (LFG) - Body ground Always Below 1 Ω

         
         

         • *: w/ Rear Fog Light

      Result
      Proceed to OK NG

   
   
   • OK

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

   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR