Headlight Signal Circuit

LIGHTING (EXT): LIGHTING SYSTEM: Headlight Signal Circuit
- Headlight Signal Circuit

DESCRIPTION

The headlight leveling ECU assembly detects the status of the low beam headlights.

WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
First check that the low beam headlights operate normally.

PROCEDURE

1. READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / HL Auto Leveling / Data List.

(e) Read the display on the Techstream.

HL Auto Leveling





OK:

Normal conditions listed above are displayed.

NG -- CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT LEVELING ECU ASSEMBLY)

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Exterior Lighting System

2. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT LEVELING ECU ASSEMBLY)

(a) Disconnect the 1G No. 1 integration relay connector.

(b) Disconnect the A46 headlight leveling ECU assembly connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. REPLACE NO. 1 INTEGRATION RELAY

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

(b) Connect the Techstream to the DLC3.

(c) Turn the power switch on (IG).

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / HL Auto Leveling / Data List.

(f) Read the display on the Techstream.

HL Auto Leveling





OK:

Normal conditions listed above are displayed.

NG -- REPLACE HEADLIGHT LEVELING ECU ASSEMBLY Removal

OK -- END (NO. 1 INTEGRATION RELAY WAS DEFECTIVE)