Toyota Sienna Service Manual: 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:
- 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 AND NAVIGATION ASSEMBLY
- Disconnect the radio and navigation assembly connector R12.
- 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
- Measure the voltage between terminal SPD of the radio and navigation assembly and body ground when the drive wheels are turned slowly.
OK: Voltage pulses as shown in the illustration.
3 CHECK HARNESS AND CONNECTOR (COMBINATION METER - RADIO AND NAVIGATION ASSEMBLY)
- Disconnect the radio and navigation assembly connector R12 and combination meter connector C10.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
4 CHECK HARNESS AND CONNECTOR (COMBINATION METER - RADIO AND NAVIGATION ASSEMBLY)
- Disconnect the radio and navigation assembly connector R12 and combination meter connector C10.
- 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.
REPLACE COMBINATION METER
Black Screen
INSPECTION PROCEDURE
1 CHECK DISPLAY SETTING
Check that the display is not in "Screen OFF" mode.
OK:
The display setting is not in "Screen OFF" mode.
2 CHECK IMAGE QUALIT ...
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 st ...
Other materials:
Poor Sound Quality in All Modes (Low Volume)
INSPECTION PROCEDURE
1 CHECK AUDIO SETTINGS
Set "BASS", "MID" and "TREB" to the initial values and
check that sound is normal.
OK:
Malfunction disappears.
2 COMPARE WITH ANOTHER VEHICLE OF SAME MODEL
Compare with another vehicle of the same model.
...
Vehicle Speed Signal Circuit between Radio Receiver 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 ...
Seating configuration variation
Cargo capacity
Weight of the removed second
seat
If removing the second seats, it is possible to load extra cargo equal
to the weight of the removed seats.
(Cargo capacity) = (Total load capacity) - (Total weight of occupants) +
(Weight of the removed second seats)
Second seats w ...
