Toyota Sienna Service Manual: Steering Pad Switch Circuit

DESCRIPTION

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

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

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

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

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE: 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 precautionary notice for the Supplemental Restraint System

1 INSPECT RADIO RECEIVER

1. Disconnect the radio receiver connector R4 or R9.
2.  Measure the resistance according to the value(s) in the table below.

Standard resistance

*1: 10 Speaker without Navigation System
*2: 6 Speaker with Rear Seat Entertainment System
*3: 6 Speaker without Rear Seat Entertainment System

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

2 INSPECT STEERING PAD SWITCH ASSEMBLY

1. Disconnect the steering pad switch LH connector.
2. Measure the resistance according to the values in the table below.

Standard resistance

3 INSPECT SPIRAL CABLE

1. Disconnect the steering pad switch and spiral cable connectors.
2.  Measure the resistance according to the value(s) in the table below.

Standard resistance

NOTICE: The spiral cable is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable may prevent the airbag from deploying. Be sure to read the page shown in the brackets

REPAIR OR REPLACE HARNESS OR CONNECTOR (SPIRAL CABLE - RADIO RECEIVER)