Toyota Sienna Service Manual: Vehicle Speed Signal Circuit between Multi-display and Combination Meter
DESCRIPTION
This circuit is necessary for the ASL (Auto Sound Leveliser) built into the radio receiver.
Speed signals are received from the combination meter and used for the ASL.
The ASL function automatically adjusts the sound data in order to enable hearing the clear audio sound even when vehicle noise increases (as vehicle noise increases, the volume is turned up etc.).
HINT:
- A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter. The signal is changed to a pulse signal at the transistor in the combination meter. Each ECU controls the respective system based on the pulse signal.
- If a short occurs in an ECU, all systems in the diagram below will not operate normally.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 CHECK OPERATION OF SPEEDOMETER
- Drive the vehicle and check if the function of the speedometer on the combination meter is normal
OK: Actual vehicle speed and the speed indicated on the speedometer are the same.
HINT: The vehicle speed sensor is functioning normally when the indication on the speedometer is normal.
2 INSPECT RADIO RECEIVER
- Disconnect the radio receiver connector.
- Measure the voltage.
- Jack up either one of the drive wheels.
- Move the shift lever to the neutral position.
- Turn the ignition switch to the ON position.
*1: 6 Speaker without Rear Seat Entertainment System.
*2: 6 Speaker with Rear Seat Entertainment System
- Measure the voltage between terminal SPD of the radio receiver and body ground when the drive wheels are turned slowly.
OK: Voltage pulses as shown in the illustration.
REPLACE RADIO RECEIVER
3 CHECK HARNESS AND CONNECTOR (COMBINATION METER - RADIO RECEIVER)
- Disconnect the radio receiver connector and combination meter connector.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
*1: 6 Speaker without Rear Seat Entertainment System.
*2: 6 Speaker with Rear Seat Entertainment System.
4 CHECK HARNESS AND CONNECTOR (COMBINATION METER - RADIO RECEIVER)
- Disconnect the radio receiver connector and combination meter connector.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
HINT: If the resistance between terminal SPD and body ground is less than 10 kΩ, there may be a short in a wire harness, connector, or an ECU that is connected to the SPD signal wire.
*1: 6 Speaker without Rear Seat Entertainment System.
*2: 6 Speaker with Rear Seat Entertainment System.
REPLACE COMBINATION METER
AVC-LAN Circuit
DESCRIPTION
Each unit of the audio system connected to the AVC-LAN (communication bus)
transfers the signal of
each switch by communication.
When a short to +B or short to ground occurs in this ...
Vehicle Speed Signal Circuit between Stereo Component Amplifier and
Combination Meter
DESCRIPTION
This circuit is necessary for the ASL (Auto Sound Leveliser) built into the
stereo component amplifier.
Speed signals are received from the combination meter and used for the ASL.
...
Other materials:
Route cannot be Calculated
INSPECTION PROCEDURE
1 CHECK MAP DISC
Check that the map disc is not deformed or cracked.
OK:
No deformations or cracks on map disc.
2 SET DESTINATION
Set another destination and check if the system can
calculate the route correctly.
OK:
Route can be correctly calculated.
NO ...
Data list / active test
1. DATA LIST
The wireless door lock control data list can be
displayed while the intelligent tester is connected to
the DLC3 with the ignition switch in the ON position.
Follow the prompts on the tester screen to access
the DATA LIST.
BODY:
2. ACTIVE TEST
HINT:
Performing the ACT ...
Read vin (vehicle identification number)
(a) The VIN reading process is shown in the flowchart
below. Reading the VIN stored in the ECM is
necessary when comparing it to the VIN provided
with the vehicle.
(b) Read the VIN using the intelligent tester.
(c) Check the vehicle's VIN.
(d) Connect the intelligent tester to the DLC3.
...
