Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM1000000018F8R
Model Year Start: 2018 Model: Sienna Prod Date Range: [11/2017 -           ]
Title: AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM: Illumination Circuit; 2018 - 2020 MY Sienna [11/2017 -        ]

Illumination Circuit

DESCRIPTION

Power is supplied to the radio and display receiver assembly and steering pad switch assembly illumination when the headlight dimmer switch assembly is in the tail or head position.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

The vehicle is equipped with an SRS (Supplemental Restraint System) which includes components such as airbags. Before servicing (including removal or installation of parts), be sure to read the Precaution in the SRS (See page 2016 - 2020 MY Sienna [12/2015 -        ]; SUPPLEMENTAL RESTRAINT SYSTEMS: AIRBAG SYSTEM: PRECAUTION ).

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK ILLUMINATION

(a) Check if the illumination for the radio and display receiver assembly, steering pad switch assembly, glove box or other parts (hazard switch, transmission control switch, etc.) comes on when the light control switch is turned to the head or tail position.

Result

Result

Proceed to

Illumination comes on for all components except steering pad switch assembly

A

Illumination comes on for all components except radio and display receiver assembly

B

No illumination comes on (radio and display receiver assembly, hazard switch, glove box, etc.)

C

Illumination comes on for all components except steering pad switch assembly and radio and display receiver assembly

D

B

GO TO STEP 4

C

GO TO LIGHTING SYSTEM

D

GO TO STEP 5

A

2.

CHECK HARNESS AND CONNECTOR (SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY - BATTERY)

(a) Disconnect the spiral cable with sensor sub-assembly connector.

*A

w/o Steering Heater

*B

w/ Steering Heater

*a

Front view of wire harness connector

(to Spiral Cable with Sensor Sub-assembly)

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

D21-8 (IL+2) - Body ground*1

Headlight dimmer switch assembly tail or head

11 to 14 V

D149-9 (IL+2) - Body ground*2

Headlight dimmer switch assembly tail or head

11 to 14 V

  • *1: w/o Steering Heater
  • *2: w/ Steering Heater
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.

INSPECT STEERING PAD SWITCH ASSEMBLY

(a) Remove the steering pad switch assembly (See page 2016 - 2020 MY Sienna [12/2015 -        ]; AUDIO / VIDEO: STEERING PAD SWITCH: REMOVAL ).

(b) Inspect the steering pad switch assembly (See page 2018 - 2020 MY Sienna [11/2017 -        ]; AUDIO / VIDEO: STEERING PAD SWITCH: INSPECTION ).

OK

REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY

NG

REPLACE STEERING PAD SWITCH ASSEMBLY

4.

CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY - BATTERY)

(a) Disconnect the radio and display receiver assembly connector.

*a

Front view of wire harness connector

(to Radio and Display Receiver Assembly)

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

D196-15 (ILL+) - Body ground

Headlight dimmer switch assembly tail or head

11 to 14 V

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

(See page 2018 MY Sienna [11/2017 - 08/2018]; AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM: PROBLEM SYMPTOMS TABLE 2019 - 2020 MY Sienna [08/2018 -        ]; AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM: PROBLEM SYMPTOMS TABLE )

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

5.

CHECK HARNESS AND CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY - COMBINATION METER ASSEMBLY)

(a) Disconnect the D196 radio and display receiver assembly connector.

(b) Disconnect the D145 combination meter assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

D196-16 (ILL-) - D145-12 (ILL-)

Always

Below 1 Ω

D196-16 (ILL-) - Body ground

Always

10 kΩ or higher

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

(See page 2018 MY Sienna [11/2017 - 08/2018]; AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM: PROBLEM SYMPTOMS TABLE 2019 - 2020 MY Sienna [08/2018 -        ]; AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM: PROBLEM SYMPTOMS TABLE )

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR