AUDIO AND VISUAL SYSTEM (for Radio and Display Type without Intuitive Parking Assist System) Steering Pad Switch Circuit

DESCRIPTION

This circuit sends an operation signal from the steering pad switch assembly to the radio and display receiver assembly.

If there is an open in the circuit, the audio system cannot be operated using the steering pad switch assembly.

If there is a short in the circuit, the same condition as when a switch is continuously depressed occurs.

Therefore, the radio and display receiver assembly cannot be operated using the steering pad switch assembly, and also the radio and display receiver assembly itself cannot function.

WIRING DIAGRAM

INSPECTION PROCEDURE

Note

The vehicle is equipped with a Supplemental Restraint System (SRS) which includes components such as airbags. Before servicing (including removal or installation of parts), be sure to read the precaution for Supplemental Restraint System Click here.

PROCEDURE

CHECK HARNESS AND CONNECTOR (STEERING PAD SWITCH SIGNAL)

Disconnect the radio and display receiver assembly connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
I155-21 (SW1) - I155-23 (SWG)	No switch pushed	95 to 105 kΩ
	Up switch pushed	Below 2.5 Ω
	Down switch pushed	313 to 345 Ω
	Volume+ switch pushed	950 to 1050 Ω
	Volume- switch pushed	2955 to 3265 Ω
I155-22 (SW2) - I155-23 (SWG)	No switch pushed	95 to 105 kΩ
	MODE/HOLD switch pushed	Below 2.5 Ω
	On hook switch pushed	313 to 345 Ω
	Off hook switch pushed	950 to 1050 Ω
	Voice switch pushed*1	2955 to 3265 Ω
I155-24 (SW3) - I155-23 (SWG)	No switch pushed	95 to 105 kΩ
	Enter switch pushed	Below 2.5 Ω
	Back switch pushed	313 to 345 Ω
	Right switch pushed	950 to 1050 Ω
	Left switch pushed	2955 to 3265 Ω

*1: w/ Voice Switch of Steering Pad Switch Assembly

INSPECT STEERING PAD SWITCH ASSEMBLY Click here

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

INSPECT STEERING PAD SWITCH ASSEMBLY

Disconnect the steering pad switch assembly connector (for 3 Spoke, w/o Voice Switch of Steering Pad Switch Assembly).
Disconnect the steering pad switch assembly connector (for 3 Spoke, w/ Voice Switch of Steering Pad Switch Assembly).
Disconnect the steering pad switch assembly connector (for 4 Spoke, w/o Voice Switch of Steering Pad Switch Assembly).
Disconnect the steering pad switch assembly connector (for 4 Spoke, w/ Voice Switch of Steering Pad Switch Assembly).

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

Standard Resistance

Tester Connection	Condition	Specified Condition
z3-11 (AU1) - z3-8 (EAU)	No switch pushed	95 to 105 kΩ
	Up switch pushed	Below 2.5 Ω
	Down switch pushed	313 to 345 Ω
	Volume+ switch pushed	950 to 1050 Ω
	Volume- switch pushed	2955 to 3265 Ω
z3-10 (AU2) - z3-8 (EAU)	No switch pushed	95 to 105 kΩ
	MODE/HOLD switch pushed	Below 2.5 Ω
	On hook switch pushed	313 to 345 Ω
	Off hook switch pushed	950 to 1050 Ω
	Voice switch pushed*1	2955 to 3265 Ω
z3-9 (AU3) - z3-8 (EAU)	No switch pushed	95 to 105 kΩ
	Enter switch pushed	Below 2.5 Ω
	Back switch pushed	313 to 345 Ω
	Right switch pushed	950 to 1050 Ω
	Left switch pushed	2955 to 3265 Ω

*1: w/ Voice Switch of Steering Pad Switch Assembly

Proceed to the next step based on the check result.

Result

Result	Proceed to
OK	A
NG (for 3 Spoke)	B
NG (for 4 Spoke)	C

Text in Illustration
*A	for 3 Spoke	*B	for 4 Spoke
*a	Component without harness connected (Steering Pad Switch Assembly)	*b	Volume+
*c	Volume-	*d	Back
*e	MODE/HOLD	*f	Up
*g	Down	*h	Left
*i	Right	*j	Enter
*k	Off hook	*l	On hook
*m	Voice	-	-

REPLACE STEERING PAD SWITCH ASSEMBLY (for 3 Spoke) Click here

REPLACE STEERING PAD SWITCH ASSEMBLY (for 4 Spoke) Click here

INSPECT SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY

Disconnect the steering pad switch assembly connector.
Disconnect the spiral cable with sensor sub-assembly connector.

Text in Illustration
*a	Component without harness connected (Spiral Cable with Sensor Sub-assembly)
*b	Steering Pad Switch Assembly Side
*c	Vehicle Side

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

Standard Resistance

Tester Connection	Condition	Specified Condition
z3-8 (EAU) - I28-3 (EAU)	Center	3 Ω or less
	2.5 rotations to the left
	2.5 rotations to the right
z3-11 (AU1) - I28-6 (AU1)	Center	3 Ω or less
	2.5 rotations to the left
	2.5 rotations to the right
z3-10 (AU2) - I28-5 (AU2)	Center	3 Ω or less
	2.5 rotations to the left
	2.5 rotations to the right
z3-9 (AU3) - I28-4 (AU3)	Center	3 Ω or less
	2.5 rotations to the left
	2.5 rotations to the right

After setting the spiral cable with sensor sub-assembly to the center position, rotate the spiral cable with sensor sub-assembly 2.5 times clockwise. Then while rotating the spiral cable with sensor sub-assembly 5 times counterclockwise, measure the resistance as shown in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
z3-8 (EAU) - I28-3 (EAU)	Always	3 Ω or less
z3-11 (AU1) - I28-6 (AU1)	Always	3 Ω or less
z3-10 (AU2) - I28-5 (AU2)	Always	3 Ω or less
z3-9 (AU3) - I28-4 (AU3)	Always	3 Ω or less

Note

Press and hold the lock located in the center of the spiral cable with sensor sub-assembly to rotate the spiral cable with sensor sub-assembly.
The spiral cable with sensor sub-assembly is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable with sensor sub-assembly may prevent the airbag from deploying. Refer to the pages shown in the brackets.
As the spiral cable with sensor sub-assembly may break, do not rotate the spiral cable with sensor sub-assembly more than the specified amount.

Tech Tips

Removal Click here
Installation Click here

REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY Click here

REPAIR OR REPLACE HARNESS OR CONNECTOR (RADIO AND DISPLAY RECEIVER ASSEMBLY - SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY)