LIGHTING SYSTEM Headlight Dimmer Switch Circuit

DESCRIPTION

The main body ECU (network gateway ECU) receives the following signals:

• Headlight dimmer switch tail, head, AUTO*1, high or high flash signal

• Front fog light switch signal*2

• Rear fog light switch signal*3




• *1: w/ Automatic Light Control System

• *2: w/ Front Fog Light

• *3: w/ Rear Fog Light

WIRING DIAGRAM

PROCEDURE

1. READ VALUE USING GTS (HEADLIGHT DIMMER SWITCH ASSEMBLY)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

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

   5. Read the display on the GTS.

      Main Body

      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*3	Rear fog light switch signal / ON or OFF	ON: Rear fog light switch on OFF: Rear fog light switch off	-
      Front Fog Light SW*2	Front fog light switch signal / ON or OFF	ON: Front fog light switch on OFF: Front fog light switch off	-
      Auto Light SW*1	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 in neither tail nor head position	-
      Lighting Hi	Light control switch head (Hi) position signal / ON or OFF	ON: Headlight high beam on OFF: Headlight high beam off	-

      
      

      • *1: w/ Automatic Light Control System

      • *2: w/ Front Fog Light

      • *3: w/ Rear Fog Light

      OK
      The display is as specified in the normal condition column.

      Result
      Result Proceed to OK A NG (Dimmer switch) B NG (Fog switch and light control switch) C

   
   

   A

   REPLACE MAIN BODY ECU (NETWORK GATEWAY ECU) Click here

   C

   INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY Click here

   B

2. INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY

   
   

   1. Remove the headlight dimmer switch assembly Click here.

   2. Inspect the headlight dimmer switch assembly Click here.

   
   

   NG

   REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY Click here

   OK

3. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH ASSEMBLY - JUNCTION BLOCK ASSEMBLY, BODY GROUND)

   
   

   1. Disconnect the 3B junction block assembly connector.

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

      Standard Resistance (Check for Open)
      for LHD Tester Connection Condition Specified Condition D50-17 (HF) - 3B-15 Always Below 1 Ω D50-11 (HU) - 3B-30 Always Below 1 Ω D50-12 (EL) - Body ground Always Below 1 Ω
      for RHD Tester Connection Condition Specified Condition D50-14 (HF) - 3B-15 Always Below 1 Ω D50-20 (HU) - 3B-30 Always Below 1 Ω D50-19 (EL) - Body ground Always Below 1 Ω

      Standard Resistance (Check for Short)
      for LHD Tester Connection Condition Specified Condition D50-17 (HF) - Body ground Always 10 kΩ or higher D50-11 (HU) - Body ground*1 Always 10 kΩ or higher
      for RHD Tester Connection Condition Specified Condition D50-14 (HF) - Body ground Always 10 kΩ or higher D50-20 (HU) - Body ground*1 Always 10 kΩ or higher

   
   

   OK

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

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

4. INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY

   
   

   1. Remove the headlight dimmer switch assembly Click here.

   2. Inspect the headlight dimmer switch assembly Click here.

   
   

   NG

   REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY Click here

   OK

5. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH ASSEMBLY - MAIN BODY ECU (NETWORK GATEWAY ECU))

   
   

   1. Disconnect the D5 main body ECU (network gateway ECU) connector.

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

      Standard Resistance (Check for Open)
      for LHD Tester Connection Condition Specified Condition D50-2 (B) - D5-26 (RFOG)*3 Always Below 1 Ω D50-4 (BFG) - D5-24 (FFOG)*2 Always Below 1 Ω D50-20 (H) - D5-2 (HEAD) Always Below 1 Ω D50-19 (A) - D5-23 (A)*1 Always Below 1 Ω D50-18 (T) - D5-25 (TAIL) Always Below 1 Ω D50-12 (EL) - Body ground Always Below 1 Ω D50-3 (LFG) - Body ground Always Below 1 Ω
      for RHD Tester Connection Condition Specified Condition D50-7 (B) - D5-26 (RFOG)*3 Always Below 1 Ω D50-9 (BFG) - D5-24 (FFOG)*2 Always Below 1 Ω D50-11 (H) - D5-2 (HEAD) Always Below 1 Ω D50-12 (A) - D5-23 (A)*1 Always Below 1 Ω D50-13 (T) - D5-25 (TAIL) Always Below 1 Ω D50-19 (EL) - Body ground Always Below 1 Ω D50-8 (LFG) - Body ground Always Below 1 Ω

      Standard Resistance (Check for Short)
      for LHD Tester Connection Condition Specified Condition D50-2 (B)*3 - Body ground Always 10 kΩ or higher D50-4 (BFG)*2 - Body ground Always 10 kΩ or higher D50-20 (H) - Body ground Always 10 kΩ or higher D50-19 (A)*1 - Body ground Always 10 kΩ or higher D50-18 (T) - Body ground Always 10 kΩ or higher
      for RHD Tester Connection Condition Specified Condition D50-7 (B)*3 - Body ground Always 10 kΩ or higher D50-9 (BFG)*2 - Body ground Always 10 kΩ or higher D50-11 (H) - Body ground Always 10 kΩ or higher D50-12 (A)*1 - Body ground Always 10 kΩ or higher D50-13 (T) - Body ground Always 10 kΩ or higher

      
      

      • *1: w/ Automatic Light Control System

      • *2: w/ Front Fog Light

      • *3: w/ Rear Fog Light

   
   

   OK

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

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR