Lighting System Back-Up Light Circuit

Body Electrical. Lexus Gs430, Gs300. Uzs190 Grs190
Lighting. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST BY INTELLIGENT TESTER

READ VALUE OF INTELLIGENT TESTER

REPLACE BACK-UP LIGHT BULB

CHECK WIRE HARNESS (NO. 1 JUNCTION BLOCK - REAR COMBINATION LIGHT (BACK-UP LH OR BACK-UP RH) - BODY GROUND)

LIGHTING SYSTEM - Back-up Light Circuit


DESCRIPTION

The back-up light turns on by receiving the park / neutral position switch signal (shift position R signal) from the luggage room junction block ECU.

WIRING DIAGRAM


Lexus Gs430, Gs300. Uzs190 Grs190.Lighting.Lighting System.Lighting System Back-Up Light Circuit


INSPECTION PROCEDURE

1.PERFORM ACTIVE TEST BY INTELLIGENT TESTER

  1. Select the Active Test, use the intelligent tester to generate a control command, and then check that the back-up light illuminates.

    Multiplex network rear ECU:

    Item
    		Test Details
    		Diagnostic Note
    Backup light
    		Back-up light ON / OFF
    		-
    OK:
    Back-up light illuminates.


OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
NG


2.READ VALUE OF INTELLIGENT TESTER

  1. Check the Data List for proper functioning of the park / neutral position switch.

    AFS ECU:

    Item
    		Measurement Item / Display (Range)
    		Normal Condition
    		Diagnostic Note
    Shift Pos-R
    		Transmission position R signal / ON or OFF
    		ON: Shift position is R
    OFF: Shift position is not R
    		-


OK
Go to step 3
NG

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

3.REPLACE BACK-UP LIGHT BULB

  1. Temporarily replace the back-up light bulb with a new or normally functioning one.

  1. Check that light bulb illuminates.

    OK:
    Back-up light bulb illuminates.


OK
END
NG


4.CHECK WIRE HARNESS (NO. 1 JUNCTION BLOCK - REAR COMBINATION LIGHT (BACK-UP LH OR BACK-UP RH) - BODY GROUND)


    Lexus Gs430, Gs300. Uzs190 Grs190.Lighting.Lighting System.Lighting System Back-Up Light Circuit

  1. Check the wire harness between the rear combination light (back-up LH) and No. 1 junction block, and the rear combination light (back-up LH) and body ground.

    1. Disconnect the a2 light connector.

    2. Disconnect the LA junction block connector.

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

      Standard resistance:
      Tester Connection
      		Specified Condition
      LA-2 (BCK1) - a2-1 (B)
      		Below 1 Ω
      LA-2 (BCK1) or a2-1 (B) - Body ground
      		10 kΩ or higher

    4. Connect the LA junction block connector.

    5. Measure the resistance of the wire harness side connector.

      Standard resistance:
      Tester Connection
      		Specified Condition
      a2-4 (E) - Body ground
      		Below 1 Ω


    Lexus Gs430, Gs300. Uzs190 Grs190.Lighting.Lighting System.Lighting System Back-Up Light Circuit

  1. Check the wire harness between the rear combination light (back-up RH) and No. 1 junction block, and the rear combination light (back-up RH) and body ground.

    1. Disconnect the a9 light connector.

    2. Disconnect the LA junction block connector.

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

      Standard resistance:
      Tester Connection
      		Specified Condition
      LA-2 (BCK1) - a9-1 (B)
      		Below 1 Ω
      LA-2 (BCK1) or a9-1 (B) - Body ground
      		10 kΩ or higher

    4. Connect the LA junction block connector.

    5. Measure the resistance of the wire harness side connector.

      Standard resistance:
      Tester Connection
      		Specified Condition
      a9-4 (E) - Body ground
      		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE