Lighting System Headlight (Hi-Beam) Circuit

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HEADLIGHT

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (MAIN BODY ECU)

INSPECT FUSE (HEAD LH, HEAD RH)

INSPECT HEADLIGHT DIMMER RELAY (Marking: DIM)

INSPECT HEADLIGHT BULB (HI-BEAM)

CHECK WIRE HARNESS (MAIN BODY ECU - BATTERY)

CHECK WIRE HARNESS (HEADLIGHT DIMMER RELAY - BATTERY)

CHECK WIRE HARNESS (HEADLIGHT DIMMER RELAY AND BODY GROUND - BULB)

INSPECT HEADLIGHT DIMMER SWITCH

CHECK WIRE HARNESS (MAIN BODY ECU - HEADLIGHT DIMMER SWITCH)

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

1. Check that the headlights (Low) come on when the light control switch is in the HEAD position.
   

   OK:

   Headlights (Low) come on.
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch on (IG) and press the intelligent tester main switch ON.
   

3. Select the item below in the ACTIVE TEST and then check the relay operates.
   
   

   Main body ECU

   Item	Test Details	Diagnostic Note
   Headlight Hi	Turn headlight dimmer switch to HI position: ON / OFF	-

   OK:

   Headlights (LOW) comes on.
   

1. Remove the HEAD LH and HEAD RH fuses from the engine room No. 2 relay block.
   

2. Measure the resistance of the fuses.
   

   Standard resistance:

   Below 1 Ω
   

1. Remove the headlight dimmer relay from the engine room No. 2 relay block.
   

2. Measure the resistance of the relay.
   

   Standard resistance:

   Tester Connection	Specified Condition
   3 - 5	10 kΩ or higher
   3 - 5	Below 1 Ω (Battery voltage applied to terminals 1 and 2)

1. Remove the headlight bulbs (Hi-beam).
   

2. Connect the positive (+) lead from the battery to terminal 2 and the negative (-) lead to terminal 1, then check that the bulb illuminates.
   

   OK:

   Bulb illuminates.
   

1. Disconnect the E19 main body ECU connector.
   

2. Measure the voltage of the wire harness side connector.
   

   Standard voltage:

   Tester Connection	Condition	Specified Condition
   E19-3 (DIM) - Body ground	Light control switch HEAD	10 to 14 V

1. Remove the headlight dimmer relay from the engine room No. 2 relay block.
   

2. Measure the voltage of the relay block.
   

   Standard resistance:

   Tester Connection	Condition	Specified Condition
   Relay block No. 2 headlight dimmer relay terminal 3 - Body ground	Light control switch HEAD	10 to 14 V

1. Remove the headlight dimmer relay from the engine room No. 2 relay block.
   

2. Disconnect the A19 and A34 headlight (Hi-beam) bulb connectors.
   

3. Measure the resistance of the wire harness side connectors.
   

   Standard resistance:

   Tester Connection	Specified Condition
   Relay block No. 2 headlight dimmer relay terminal 5 - A19-2	Below 1 Ω
   Relay block No. 2 headlight dimmer relay terminal 5 or A19-2 - Body ground	10 kΩ or higher
   Relay block No. 2 headlight dimmer relay terminal 5 - A34-2	Below 1 Ω
   Relay block No. 2 headlight dimmer relay terminal 5 or A34-2 - Body ground	10 kΩ or higher
   A19-1 - Body ground	Below 1 Ω
   A34-1 - Body ground	Below 1 Ω

1. Remove the headlight dimmer switch.
   

2. Measure the resistance of the switch.
   
   

   Standard resistance:

   for LH side

   Tester Connection	Condition	Specified Condition
   20 (H) - 12 (EL)	Light control switch HEAD	Below 1 Ω
   11 (HU) - 12 (EL)	Headlight dimmer switch HIGH	Below 1 Ω
   11 (HU) - 12 (EL)	Headlight dimmer switch LOW	10 kΩ or higher
   17 (HF) - 12 (EL)	Headlight dimmer switch FLASH	Below 1 Ω
   17 (HF) - 12 (EL)	Headlight dimmer switch except FLASH	10 kΩ or higher

   for RH side

   Tester Connection	Condition	Specified Condition
   11 (H) - 19 (EL)	Light control switch HEAD	Below 1 Ω
   20 (HU) - 19 (EL)	Headlight dimmer switch HIGH	Below 1 Ω
   20 (HU) - 19 (EL)	Headlight dimmer switch LOW	10 kΩ or higher
   14 (HF) - 19 (EL)	Headlight dimmer switch FLASH	Below 1 Ω
   14 (HF) - 19 (EL)	Headlight dimmer switch except FLASH	10 kΩ or higher

1. Disconnect the E15 headlight dimmer switch connector.
   

2. Disconnect the E18 and E20 main body ECU connectors.
   

3. Disconnect the IJ instrument panel junction block connector.
   

4. Measure the resistance of the wire harness side connectors.
   
   

   Standard resistance:

   for LH side

   Tester Connection	Specified Condition
   E20-12 (HEAD) - E15-20 (H)	Below 1 Ω
   E20-12 (HEAD) or E15-20 (H) - Body ground	10 kΩ or higher
   E18-22 (HF) - E15-17 (HF)	Below 1 Ω
   E18-22 (HF) or E15-17 (HF) - Body ground	10 kΩ or higher
   IJ-4 (HU) - E15-11 (HU)	Below 1 Ω
   IJ-4 (HU) or E15-11 (HU) - Body ground	10 kΩ or higher

   for RH side

   Tester Connection	Specified Condition
   E20-12 (HEAD) - E15-11 (H)	Below 1 Ω
   E20-12 (HEAD) or E15-11 (H) - Body ground	10 kΩ or higher
   E18-22 (HF) - E15-14 (HF)	Below 1 Ω
   E18-22 (HF) or E15-14 (HF) - Body ground	10 kΩ or higher
   IJ-4 (HU) - E15-20 (HU)	Below 1 Ω
   IJ-4 (HU) or E15-20 (HU) - Body ground	10 kΩ or higher