Toyota Sienna Service Manual: Illumination Circuit
DESCRIPTION
Power is supplied to the radio receiver and steering pad switch illumination when the light control switch is in the TAIL or HEAD position.
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 CHECK ILLUMINATION
- Check if the illumination for the radio receiver, steering pad switch, glove box or others (hazard switch, cigarette lighter, etc.) comes on when the light control switch is turned to the HEAD or TAIL position.
Result
2 CHECK HARNESS AND CONNECTOR (BATTERY - SPIRAL CABLE)
- Disconnect the spiral cable connector.
- Measure the voltage according to the value(s) in the table below.
Standard voltage
3 INSPECT STEERING PAD SWITCH ASSEMBLY
- Disconnect the steering pad switch connector.
- Connect the positive (+) lead to terminal ILL+ and the negative (-) lead to terminal EAU of the steering pad switch assembly connector.
- Check if the illumination for the steering pad switch assembly comes on.
OK: Illumination for the steering pad switch assembly comes on.
4 INSPECT SPIRAL CABLE
- Disconnect the steering pad switch and and spiral cable 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
5 CHECK HARNESS AND CONNECTOR (SPIRAL CABLE - RADIO RECEIVER)
- Disconnect the connectors from the radio receiver and spiral cable.
- 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
6 CHECK HARNESS AND CONNECTOR (BATTERY - RADIO RECEIVER)
- Disconnect the radio receiver connector.
- Measure the voltage according to the value(s) in the table below.
Standard voltage
*1: 10 Speaker without Navigation System
*2: 6 Speaker with Rear Seat Entertainment System
*3: 6 Speaker without Rear Seat Entertainment System
7 CHECK HARNESS AND CONNECTOR (RADIO RECEIVER - COMBINATION METER)
- Disconnect the radio receiver connector and combination meter connector.
- 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
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 steerin ...
Speaker Circuit
DESCRIPTION
When the vehicle has a built-in type amplifier, a sound signal is
sent from the radio receiver to the
speakers via the "6 Speaker System" circuit.
When the ...
Other materials:
Fail-safe chart
1. FAIL-SAFE
This function minimizes the loss of the ECT functions
when any malfunction occurs in a sensor or solenoid.
(a) ATF (Automatic Transmission Fluid) temperature
sensor:
When the ATF temperature sensor has a
malfunction, 5th upshift is prohibited.
(b) Counter gear speed sensor NC ...
Basic inspection
(a) WHEN MEASURING RESISTANCE OF
ELECTRONIC PARTS
(1) Unless otherwise stated, all resistance
measurements should be made at an ambient
temperature of 20°C (68°F). Resistance
measurements may be inaccurate if measured
at high temperatures, i.e. immediately after the
vehicle has been running ...
Installation
1. INSTALL OCCUPANT CLASSIFICATION ECU
Check that the ignition switch is off.
Check that the negative battery (-) terminal is
disconnected.
CAUTION:
After disconnecting the negative battery
terminal, wait for at least 90 seconds before
starting the operation.
...