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:
Before refueling the vehicle
Close all the doors and windows, and turn the engine switch to the
“LOCK” position (vehicles without a smart key system) or off (vehicles
with a smart key system).
Confirm the type of fuel.
Fuel type
Fuel tank opening for unleaded gasoline
To help prevent incorrect fueling, your ve ...
Air Mix Damper Position Sensor Circuit (Passenger Side)
DESCRIPTION
This sensor detects the position of the air mix control servo motor (air mix
damper) and sends the
appropriate signals to the A/C amplifier. The position sensor is built in the
air mix control servo motor. The
position sensor's resistance changes as the air mix control servo m ...
The Other Caller's Voice cannot be Heard, is too Quiet, or Distorted
INSPECTION PROCEDURE
1 CHECK CELLULAR PHONE
Check if the voice on the other side can be heard using a
cellular phone.
OK:
Voice can be heard
2 CHECK NAVIGATION SYSTEM
Check that navigation sound can be heard from the
driver side speaker.
OK:
Audio sound can be heard
3 CHECK SE ...
