Toyota Corolla Cross: Front Side Marker Light Circuit

DESCRIPTION

When the light control switch is in the TAIL or HEAD position, the main body ECU (multiplex network body ECU) sends an illumination request signal to the headlight ECU sub-assembly LH/RH to illuminate the front side marker lights.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

• Inspect the bulbs for circuits related to this system before performing the following procedure.
• If the headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the headlight ECU sub-assembly LH.

  Click here

PROCEDURE

1.	CHECK LIGHTS

(a) Check the illumination of each front side marker light.

Result	Proceed to
LH side front side marker light does not illuminate	A
RH side front side marker light does not illuminate	B

B

GO TO STEP 5

A

2.	PERFORM ACTIVE TEST USING GTS

(a) Perform the Active Test according to the display on the GTS.

Body Electrical > Headlight Control > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Clearance Light (+ Front Side Marker Light)	Parking lights and side marker lights	OFF or ON	-

Body Electrical > Headlight Control > Active Test

Tester Display
Clearance Light (+ Front Side Marker Light)

OK:

Front side marker light illuminates.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

3.	CHECK HEADLIGHT UNIT ASSEMBLY LH

(a) Interchange the headlight unit assembly LH with RH and connect the connectors.

Click here

NEXT

4.	CHECK OPERATION (FRONT SIDE MARKER LIGHT)

(a) Check the operation of front side marker light.

Result	Proceed to
LH side front side marker light does not illuminate	A
RH side front side marker light does not illuminate	B

A

REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH

B

REPLACE HEADLIGHT UNIT ASSEMBLY LH

5.	PERFORM ACTIVE TEST USING GTS

(a) Perform the Active Test according to the display on the GTS.

Body Electrical > Headlight Control (Sub) > Active Test

Tester Display	Measurement Item	Control Range	Diagnostic Note
Clearance Light (+ Front Side Marker Light)	Parking lights and side marker lights	OFF or ON	-

Body Electrical > Headlight Control (Sub) > Active Test

Tester Display
Clearance Light (+ Front Side Marker Light)

OK:

Front side marker light illuminates.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

6.	CHECK HEADLIGHT UNIT ASSEMBLY RH

(a) Interchange the headlight unit assembly RH with LH and connect the connectors.

Click here

NEXT

7.	CHECK OPERATION (FRONT SIDE MARKER LIGHT)

(a) Check the operation of front side marker light.

Result	Proceed to
RH side front side marker light does not illuminate	A
LH side front side marker light does not illuminate	B

A

REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH

B

REPLACE HEADLIGHT UNIT ASSEMBLY RH

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