LIGHTING SYSTEM Headlight Signal Circuit

DESCRIPTION

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

WIRING DIAGRAM

B001M9CE04
*a No.1 Integration Relay
*b Headlight Leveling ECU Assembly

CAUTION / NOTICE / HINT

Note

First check that the low beam headlights operate normally.

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER


    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.

    OK

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

    NG

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


    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

  3. REPLACE NO. 1 INTEGRATION RELAY


    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.

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

    A

    END (NO. 1 INTEGRATION RELAY WAS DEFECTIVE)

    B

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY (for LHD) Click here

    C

    REPLACE HEADLIGHT LEVELING ECU ASSEMBLY (for RHD) Click here