LIGHTING SYSTEM Headlight Dimmer Switch Circuit

DESCRIPTION

The main body 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




• *1: w/ Automatic Light Control System

• *2: w/ Front Fog Light

The combination meter assembly receives the following signals:

• Turn signal switch turn right or turn left signal

WIRING DIAGRAM

PROCEDURE

1. READ VALUE USING INTELLIGENT TESTER

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the intelligent tester on.

   4. Enter the following menus:

      
      

      1. for Main Body ECU: Body / Main Body / Data List.

      2. for Combination Meter: Body / Combination Meter / Data List.

   5. According to the display on the intelligent tester, read the Data List.

      Main Body

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      Dimmer SW	Dimmer switch high signal / OFF or ON	OFF: Dimmer switch in low position ON: Dimmer switch in high or high flash position	-
      Passing Light SW	Dimmer switch high flash signal / OFF or ON	OFF: Dimmer switch not in high flash position ON: Dimmer switch in high flash position	-
      Rear Fog Light SW	Rear fog light switch signal / OFF or ON	OFF: Rear fog light switch off ON: Rear fog light switch on	-
      Front Fog Light SW*1	Front fog light switch signal / OFF or ON	OFF: Front fog light switch off ON: Front fog light switch on	-
      Auto Light SW*2	Light control switch AUTO signal / OFF or ON	OFF: Light control switch not in AUTO position ON: Light control switch in AUTO position	-
      Head Light SW (Head)	Light control switch HEAD signal / OFF or ON	OFF: Light control switch not in HEAD position ON: Light control switch in HEAD position	-
      Head Light SW (Tail)	Light control switch TAIL signal / OFF or ON	OFF: Light control switch not in TAIL and HEAD position ON: Light control switch in TAIL or HEAD position	-

      Combination Meter

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      Turn Signal Switch (Right)	Turn signal switch signal (turn right) / OFF or ON	OFF: Turn signal switch right off (turn right) ON: Turn signal switch right on (turn right)	-
      Turn Signal Switch (Left)	Turn signal switch signal (turn left) / OFF or ON	OFF: Turn signal switch left off (turn left) ON: Turn signal switch left on (turn left)	-

      OK
      Normal conditions listed above are displayed.

      Result

      Result	Proceed to
      OK	A
      NG (Light control switch, dimmer switch or fog light switch*1)	B
      NG (Turn signal switch)	C

      
      

      • *1: w/ Front Fog Light

      • *2: w/ Automatic Light Control System

   
   

   A

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

   C

   INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY (TURN SIGNAL SWITCH) Click here

   B

2. INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY (LIGHT CONTROL SWITCH, DIMMER SWITCH OR FOG LIGHT SWITCH)

   
   

   1. 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 - MAIN BODY ECU AND BODY GROUND)

   
   

   1. Disconnect the F9 headlight dimmer switch assembly connector.

   2. Disconnect the F76 main body ECU connector.

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

      Standard Resistance

      Tester Connection Condition Specified Condition F9-2 (B) - F76-1 (RFOG) Always Below 1 Ω F9-4 (BFG) - F76-27 (FFOG)*1 Always Below 1 Ω F9-11 (HU) - F76-5 (HU) Always Below 1 Ω F9-17 (HF) - F76-8 (HF) Always Below 1 Ω F9-18 (T) - F76-30 (TAIL) Always Below 1 Ω F9-19 (A) - F76-28 (A)*2 Always Below 1 Ω F9-20 (H) - F76-29 (HEAD) Always Below 1 Ω F9-3 (LFG) - Body ground Always Below 1 Ω F9-12 (EL) - Body ground Always Below 1 Ω F9-2 (B) - Body ground Always 10 kΩ or higher F9-4 (BFG) - Body ground*1 Always 10 kΩ or higher F9-11 (HU) - Body ground Always 10 kΩ or higher F9-17 (HF) - Body ground Always 10 kΩ or higher F9-18 (T) - Body ground Always 10 kΩ or higher F9-19 (A) - Body ground*2 Always 10 kΩ or higher F9-20 (H) - Body ground Always 10 kΩ or higher

      
      

      • *1: w/ Front Fog Light

      • *2: w/ Automatic Light Control System

   
   

   OK

   REPLACE MAIN BODY ECU Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

4. INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY (TURN SIGNAL SWITCH)

   
   

   1. 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 - COMBINATION METER ASSEMBLY AND BODY GROUND)

   
   

   1. Disconnect the F9 headlight dimmer switch assembly connector.

   2. Disconnect the F3 combination meter assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition F9-13 (TR) - F3-9 (ER) Always Below 1 Ω F9-15 (TL) - F3-10 (EL) Always Below 1 Ω F9-12 (EL) - Body ground Always Below 1 Ω F9-13 (TR) - Body ground Always 10 kΩ or higher F9-15 (TL) - Body ground Always 10 kΩ or higher

   
   

   OK

   REPLACE COMBINATION METER ASSEMBLY Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR