Lexus IS250 IS220d GSE20 ALE20 - LIGHTING

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE OF INTELLIGENT TESTER

INSPECT OVERHEAD J/B

CHECK HARNESS AND CONNECTOR (OVERHEAD J/B - MAIN BODY ECU RH)

INSPECT OVERHEAD J/B

CHECK HARNESS AND CONNECTOR (OVERHEAD J/B - MAIN BODY ECU LH)

INSPECT OVERHEAD J/B

LIGHTING SYSTEM - Interior Light Switch Signal Circuit

DESCRIPTION

The main body ECU RH receives information on the front interior light switch (marked ON/OFF).


The main body ECU LH receives information on the front interior light switch (marked DOOR).


According to the position of each switch, the main body ECU RH controls the turning on and off of the interior lights, and the main body ECU LH controls the illuminated entry system.


WIRING DIAGRAM

Lighting System - Interior Light Switch Signal Circuit. LIGHTING. Lexus IS250 IS220d GSE20 ALE20

INSPECTION PROCEDURE

1.READ VALUE OF INTELLIGENT TESTER

Connect the intelligent tester to the DLC3.

Turn the engine switch on (IG).

Turn the intelligent tester main switch on.

Select the item(s) below in the DATA LIST, and read the display on the intelligent tester.

DATA LIST: Body (Main Body ECU RH)
ItemMeasurement Item / Display
(Range)		Normal ConditionDiagnostic Note
Illumination SWFront interior light switch (marked ON/OFF) signal/ ON or OFFON: Front interior light switch (marked ON/OFF) is pushed in
OFF: Front interior light switch (marked ON/OFF) is not pushed in		-
DATA LIST: Body No. 3 (Main Body ECU LH)
ItemMeasurement Item / Display
(Range)		Normal ConditionDiagnostic Note
Interior LightFront interior light switch (marked DOOR) signal/ ON or OFFON: Front interior light switch (marked DOOR) is pushed in
OFF: Front interior light switch (marked DOOR) is not pushed in		-
  • OK:
  • Switch condition can be displayed.
  • Result:
  • ResultProceed to
    Indication for "ILLUMI SW" does not changeA
    Indication for "INTERIOR LIGHT" does not changeB
    Indications for both "ILLUMI SW" and "INTERIOR LIGHT" do not changeC
    OKD
A
Go to step 2
B
Go to step 4
C
Go to step 6
D
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
2.INSPECT OVERHEAD J/B
Lighting System - Interior Light Switch Signal Circuit. LIGHTING. Lexus IS250 IS220d GSE20 ALE20

Remove the overhead J/B.

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

  • Standard resistance:
  • Tester ConnectionSwitch Condition Specified Condition
    R5-34 (CILL) - R5-18 (GND3) Front interior light switch (marked ON/OFF) is not pushed in10 kΩ or higher
    R5-34 (CILL) - R5-18 (GND3) Front interior light switch (marked ON/OFF) is pushed inApprox. 10 Ω
NG
REPLACE OVERHEAD J/B
OK
3.CHECK HARNESS AND CONNECTOR (OVERHEAD J/B - MAIN BODY ECU RH)
Lighting System - Interior Light Switch Signal Circuit. LIGHTING. Lexus IS250 IS220d GSE20 ALE20

Disconnect the R5 overhead J/B connector.

Disconnect the J75 main body ECU RH connector.

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

  • Standard resistance:
  • Tester ConnectionCondition Specified Condition
    R5-34 (CILL) - J75-4 (UL2)AlwaysBelow 1 Ω
    R5-34 (CILL) - Body ground Always10 kΩ or higher
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE MAIN BODY ECU RH (COWL SIDE J/B RH)
4.INSPECT OVERHEAD J/B
Lighting System - Interior Light Switch Signal Circuit. LIGHTING. Lexus IS250 IS220d GSE20 ALE20

Remove the overhead J/B.

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

  • Standard resistance:
  • Tester ConnectionSwitch Condition Specified Condition
    R5-35 (DOOR) - R5-18 (GND3)Front interior light switch (marked DOOR) is not pushed in10 kΩ or higher
    R5-35 (DOOR) - R5-18 (GND3) Front interior light switch (marked DOOR) is pushed inApprox. 10 Ω
NG
REPLACE OVERHEAD J/B
OK
5.CHECK HARNESS AND CONNECTOR (OVERHEAD J/B - MAIN BODY ECU LH)
Lighting System - Interior Light Switch Signal Circuit. LIGHTING. Lexus IS250 IS220d GSE20 ALE20

Disconnect the R5 overhead J/B connector.

Disconnect the Q3 main body ECU LH connector.

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

  • Standard resistance:
  • Tester ConnectionCondition Specified Condition
    R5-35 (DOOR) - Q3-11 (BDCY)AlwaysBelow 1 Ω
    R5-35 (DOOR) - Body groundAlways10 kΩ or higher
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE MAIN BODY ECU LH (COWL SIDE J/B LH)
6.INSPECT OVERHEAD J/B
Lighting System - Interior Light Switch Signal Circuit. LIGHTING. Lexus IS250 IS220d GSE20 ALE20

Remove the overhead J/B.

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

  • Standard resistance:
  • Tester ConnectionSwitch Condition Specified Condition
    R5-35 (DOOR) - R5-18 (GND3)Front interior light switch (marked DOOR) is not pushed in10 kΩ or higher
    R5-35 (DOOR) - R5-18 (GND3) Front interior light switch (marked DOOR) is pushed inApprox. 10 Ω
    R5-34 (CILL) - R5-18 (GND3) Front interior light switch (marked ON/OFF) is not pushed in10 kΩ or higher
    R5-34 (CILL) - R5-18 (GND3) Front interior light switch (marked ON/OFF) is pushed inApprox. 10 Ω
NG
REPLACE OVERHEAD J/B
OK
REPAIR OR REPLACE HARNESS OR CONNECTOR (OVERHEAD J/B GROUND CIRCUIT)
LEXUS IS250, IS220d / GSE20 ALE20
LIGHTING
Lexus IS250 IS220d GSE20 ALE20
LIGHTING SYSTEM