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 navigation system cannot be operated using the steering pad switch.
If there is a short in the circuit, the resulting condition is the same as if the switch were continuously depressed. Therefore, the radio and navigation assembly cannot be operated using the steering pad switch, and the radio and navigation assembly itself cannot function.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE: The vehicle is equipped with an SRS (Supplemental Restraint System) such as the airbags. Before servicing (including removal or installation of parts), be sure to read the precautionary notice for the Supplemental Restraint System (
1 INSPECT RADIO AND NAVIGATION ASSEMBLY
- Disconnect the radio and navigation assembly connector R13.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
2 INSPECT STEERING PAD SWITCH ASSEMBLY
- Disconnect the steering pad switch assembly connector A.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
3 INSPECT SPIRAL CABLE SUB-ASSEMBLY
- Disconnect the steering pad switch assembly and spiral cable sub-assembly connectors.
- 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 SUB-ASSEMBLY - RADIO AND NAVIGATION ASSEMBLY)
4 INSPECT STEERING PAD SWITCH CABLE
- Disconnect the steering pad switch LH and the steering pad switch RH.
- Measure the resistance according to the value(s) in the table below
Standard resistance
5 INSPECT STEERING PAD SWITCH RH
- Reconnect the steering pad switch RH.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
REPLACE STEERING PAD SWITCH LH
Vehicle Speed Signal Circuit between Radio and Navigation Assembly
and Combination Meter
DESCRIPTION
The radio and navigation assembly receives a vehicle speed signal from the
combination meter and
information about the GPS antenna, and then adjusts vehicle position.
HINT:
...
Illumination Circuit
DESCRIPTION
Power is supplied to the radio and navigation assembly and steering pad
switch illumination when the
light control switch is in the TAIL or HEAD position.
WIRING DIAGRAM
INSPECTI ...
Other materials:
Back-up Power Source Circuit
DESCRIPTION
This is the back-up power source for the A/C amplifier. Power is supplied
even when the ignition switch is
off and is used for diagnostic trouble code memory, etc.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT FUSE (ECU-B)
(a) Remove the ECU-B fuse from the engine room juncti ...
Disassembly
1. REMOVE FRONT SEAT SIDE TABLE LEG COVER (w/
Table)
Using a screwdriver, disengage the claws and
remove the seat side table leg cover.
HINT:
Tape the screwdriver tip before use.
2. REMOVE FRONT SEAT SIDE TABLE (w/ Table)
Remove the 4 nuts and seat side table.
Rem ...
Removal
HINT:
Use the same procedures for the RH side and LH side.
The procedures listed below are for the LH side.
1. PRECAUTION
CAUTION:
Be sure to read "PRECAUTION" thoroughly before
servicing.
2. DISCONNECT CABLE FROM NEGATIVE BATTERY
TERMINAL
CAUTION:
Wait for 90 s ...
