Seat Illumination Circuit

LIGHTING: LIGHTING SYSTEM: Seat Illumination Circuit
- Seat Illumination Circuit

DESCRIPTION

The seat illumination can be canceled using the overhead J/B switch.

The turning on and off of the seat illumination 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 seat illumination 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 seat illumination turns off and remains off.

Normal operation will resume when the conditions required to turn on the seat illumination are met again.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK PERSONAL LIGHT (OPERATION)

HINT
The personal lights and seat illumination share the same power source circuit. Therefore, if none of them come on, inspect the power source circuit first.

(a) Push the personal light switches.

(b) Check that the personal lights come on.

OK:

Personal lights come on.

NG -- CHECK HARNESS AND CONNECTOR (POWER SOURCE)
OK -- Continue to next step.

2. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Body No. 3 / Active Test.

(e) Check the operation.

Body No. 3 (Main Body ECU LH):





OK:

Front and rear seat illumination comes on.

Result:





HINT
If the rear seat illumination comes on normally, but the front seat illumination does not come on, there is an open circuit in the overhead J/B.

A -- REPLACE OVERHEAD J/B

B -- INSPECT REAR DOME LIGHT ASSEMBLY (REAR SEAT ILLUMINATION)

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

D -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

3. INSPECT REAR DOME LIGHT ASSEMBLY (REAR SEAT ILLUMINATION)

(a) Remove the rear dome light assembly.





(b) Connect the (+) lead from the battery to terminal 2 and the (-) lead to terminal 5, and then check that the seat illumination comes on.

OK:

Seat illumination comes on.

NG -- REPLACE REAR DOME LIGHT ASSEMBLY
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (OVERHEAD J/B - REAR DOME LIGHT ASSEMBLY)

(a) Disconnect the R8 rear dome light assembly connector.





(b) Disconnect the R5 overhead J/B connector.

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

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE OVERHEAD J/B

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

(a) Disconnect the Q3 main body ECU LH connector.





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

Standard voltage:





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

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

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

(a) Disconnect the Q3 main body ECU LH connector.





(b) Disconnect the R5 overhead J/B connector.

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

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE OVERHEAD J/B

7. CHECK HARNESS AND CONNECTOR (POWER SOURCE)

(a) Disconnect the R5 overhead J/B connector.





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

Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE OVERHEAD J/B