LIGHTING SYSTEM > Headlight Signal Circuit

for Preparation Click here

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

First check that the low beam headlights operate normally.

1. Connect the intelligent tester to the DLC3.
   

2. Turn the power switch on (IG).
   

3. Turn the intelligent tester on.
   

4. Enter the following menus: Body / HL Auto Leveling / Data List.
   

5. Read the display on the intelligent tester.
   
   

   HL Auto Leveling 

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Headlight Low Beam State	Low beam headlight state/ON or OFF	ON: Low beam headlights on OFF: Low beam headlights off	-

   OK:

   Normal conditions listed above are displayed.
   

NG	Go to step 2

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

1. Disconnect the 1G No. 1 integration relay connector.
   

2. Disconnect the A46 headlight leveling ECU assembly connector.
   

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

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   1G-11 (HL4B) - A46-3 (HDLP)	Always	Below 1 Ω
   1G-11 (HL4B) - Body ground	Always	10 kΩ or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

1. Replace the No. 1 integration relay with a new or a known good one (Click here).
   

2. Connect the intelligent tester to the DLC3.
   

3. Turn the power switch on (IG).
   

4. Turn the intelligent tester on.
   

5. Enter the following menus: Body / HL Auto Leveling / Data List.
   

6. Read the display on the intelligent tester.
   

OK:

Normal conditions listed above are displayed.

Result:

Result	Proceed to
OK	A
NG (for LHD)	B
NG (for RHD)	C

B	REPLACE HEADLIGHT LEVELING ECU ASSEMBLY (for LHD) (Click here)
C	REPLACE HEADLIGHT LEVELING ECU ASSEMBLY (for RHD) (Click here)

A
END (NO. 1 INTEGRATION RELAY WAS DEFECTIVE)