Lighting. Lighting System Scuff Plate Light Circuit

Body Electrical. Lexus Is250, Is220D. Gse20 Ale20

Lighting. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST BY INTELLIGENT TESTER

INSPECT SCUFF PLATE LIGHT (FRONT LH)

CHECK HARNESS AND CONNECTOR (SCUFF PLATE LIGHT - BODY GROUND)

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - SCUFF PLATE LIGHT)

INSPECT SCUFF PLATE LIGHT (FRONT RH)

CHECK HARNESS AND CONNECTOR (SCUFF PLATE LIGHT - BODY GROUND)

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - SCUFF PLATE LIGHT)

CHECK HARNESS AND CONNECTOR (POWER SOURCE OF SCUFF PLATE LIGHT)

LIGHTING SYSTEM - Scuff Plate Light Circuit

DESCRIPTION

The operation timing of the scuff plate lights is the same as that of the front and rear interior lights.
The scuff plate lights turn on when a door is opened, and turn off when the door is closed. This illumination setting can be canceled using the overhead J/B switch.
In addition, the scuff plate lights blink while the theft deterrent system is sounding an alarm.
The turning on and off of the scuff plate lights is controlled by the main body ECU LH based on various signals received through BEAN communication.
The main body ECU LH includes a MOS-FET (Metal Oxide Semiconductor - Field Effect Transistor) circuit that fades the scuff plate lights in and out by duty control.
This MOS-FET circuit has an overheat protection function as a fail-safe. If the main body ECU LH becomes excessively hot, the scuff plate lights turn off and remain off.
Normal operation will resume when the conditions required to turn on the scuff plate lights are met again.

WIRING DIAGRAM

Lexus Is250, Is220D. Gse20 Ale20.Lighting.Lighting System.Lighting System Scuff Plate Light Circuit

INSPECTION PROCEDURE

1.PERFORM ACTIVE TEST BY INTELLIGENT TESTER

Connect the intelligent tester to the DLC3.

Turn the engine switch on (IG).

Turn the intelligent tester on.

Select the item(s) below in the ACTIVE TEST, and check the operation.

ACTIVE TEST: Body No. 3 (Main Body ECU LH)
Item
Test Details
Diagnostic Note
Interior Light Operation
Interior light ON / OFF
-
OK:
The scuff plate light LH and RH come on.

Result:

Result
Proceed to
Scuff plate light LH does not come on
A
Scuff plate light RH does not come on
B
Neither LH nor RH light comes on
C
OK
D

ACTIVE TEST: Body No. 3 (Main Body ECU LH)
Item	Test Details	Diagnostic Note
Interior Light Operation	Interior light ON / OFF	-

Go to step 5

Go to step 8

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

A

2.INSPECT SCUFF PLATE LIGHT (FRONT LH)

Remove the scuff plate light.

Connect the (+) lead from the battery to terminal 2 and the (-) lead to terminal 1, and then check that the scuff plate light comes on.
OK:
The scuff plate light comes on.

REPLACE SCUFF PLATE LIGHT

OK

3.CHECK HARNESS AND CONNECTOR (SCUFF PLATE LIGHT - BODY GROUND)

Disconnect the Q8 scuff plate light connector.

Measure the voltage according to the value(s) in the table below.
Standard voltage:
Tester Connection
Condition
Specified Condition
Q8-2 (+) - Body ground
Always
10 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - SCUFF PLATE LIGHT)

Disconnect the Q8 scuff plate light connector.

Disconnect the LA main body ECU LH connector.

Measure the resistance according to the value(s) in the table below.
Standard resistance:
Tester Connection
Condition
Specified Condition
LA-19 (ILE1) - Q8-1 (-)
Always
Below 1 Ω
LA-19 (ILE1) - Body ground
Always
10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE MAIN BODY ECU LH (COWL SIDE J/B LH)

5.INSPECT SCUFF PLATE LIGHT (FRONT RH)

Remove the scuff plate light.

Connect the (+) lead from the battery to terminal 2 and the (-) lead to terminal 1, and then check that the scuff plate light comes on.
OK:
The scuff plate light comes on.

REPLACE SCUFF PLATE LIGHT

OK

6.CHECK HARNESS AND CONNECTOR (SCUFF PLATE LIGHT - BODY GROUND)

Disconnect the P2 scuff plate light connector.

Measure the voltage according to the value(s) in the table below.
Standard voltage:
Tester Connection
Condition
Specified Condition
P2-2 (+) - Body ground
Always
10 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

7.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU LH - SCUFF PLATE LIGHT)

Disconnect the P2 scuff plate light connector.

Disconnect the LA main body ECU LH connector.

Measure the resistance according to the value(s) in the table below.
Standard resistance:
Tester Connection
Condition
Specified Condition
LA-19 (ILE1) - P2-1 (-)
Always
Below 1 Ω
LA-19 (ILE1) - Body ground
Always
10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE MAIN BODY ECU LH (COWL SIDE J/B LH)

8.CHECK HARNESS AND CONNECTOR (POWER SOURCE OF SCUFF PLATE LIGHT)

HINT:

If neither of the scuff plate lights comes on as a result of the ACTIVE TEST, there may be problems in the power source and main body ECU LH.
Perform the following inspection on either the LH or RH side.

Disconnect the Q8 or P2 scuff plate light connector.

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

Standard voltage:
Front Door RH:
Tester Connection
Condition
Specified Condition
Q8-2 (+) - Body ground
Always
10 to 14 V
Front Door LH:
Tester Connection
Condition
Specified Condition
P2-2 (+) - Body ground
Always
10 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE MAIN BODY ECU LH (COWL SIDE J/B LH)

Result	Proceed to
Scuff plate light LH does not come on	A
Scuff plate light RH does not come on	B
Neither LH nor RH light comes on	C
OK	D

Tester Connection	Condition	Specified Condition
Q8-2 (+) - Body ground	Always	10 to 14 V

Tester Connection	Condition	Specified Condition
LA-19 (ILE1) - Q8-1 (-)	Always	Below 1 Ω
LA-19 (ILE1) - Body ground	Always	10 kΩ or higher