Toyota Sienna Service Manual: System description
1. GENERAL
- This system uses ultrasonic sensors to detect any
obstacles at the corners and the rear of the vehicle.
The system then informs the driver of the distance between the sensors and the obstacles as well as their positions by indicating them on the clearance sonar display and by sounding a buzzer.
2. FUNCTIONS OF COMPONENTS
|
Components |
Function |
| Ultrasonic Sensor | Ultrasonic sensor consists of a sensor portion that transmits and receives ultrasonic waves and a pre-amplifier that amplifies the waves. The ultrasonic sensor outputs the ultrasonic transmission and reception signals to the clearance warning ECU. |
| Clearance Sonar Main Switch | Turns the clearance sonar system on and off. |
| Clearance Warning Buzzer | Emits an intermittent sound to inform the driver that the ECU has detected an obstacle within prescribed ranges. |
| Clearance Warning ECU | Judges the approximate distance between the vehicle and the obstacle based on the signals from the ultrasonic sensors and sends the display signal to the clearance sonar indicator and the buzzer signal to the clearance warning buzzer. |
| Indicators | Displays the location of the obstacle and the approximate distance between the vehicle and the obstacle. |
| Speed Sensor | Detects speed of each wheel and inputs the data into the clearance warning ECU via the combination meter. |
| Park / Neutral Position Switch (A/T) | Sends a signal that activates the clearance sonar system when the shift lever is moved to the R position. |
3. OPERATION EXPLANATION
- The clearance warning ECU determines whether the clearance sonar system should be operated based on the clearance sonar main switch on/off stratus, the shift position and the vehicle speed.
- When the system operates, the clearance warning
ECU transmits ultrasonic waves from the ultrasonic
sensors. If these waves encounter an obstacle
within one or more of the sensors' ranges, the
waves are reflected back to the sensors, which
transmit them to the clearance warning ECU.
Based on this information, the clearance warning ECU sends signals to the indicator and the clearance warning buzzer. The approximate distance between the vehicle and the obstacle is then indicated, and the buzzer sounds.
HINT: Refer to "OPERATION CHECK" for detailed operation
Parts location
SYSTEM DIAGRAM
...
How to proceed with
troubleshooting
1 VEHICLE BROUGHT TO WORKSHOP
2 CUSTOMER PROBLEM ANALYSIS
3 CHECK INITIAL CHECK FUNCTION
4 PROBLEM SYMPTOMS TABLE
THE CORRESPONDING SYSTEM DOES NOT EXIST (Go to step 5)
5 BASED ON THE MALFUNCTION ...
Other materials:
Inspection
1. INSPECT REAR DRIVE SHAFT ASSEMBLY LH
(a) Check that there is no remarkable play in the radial
direction of the outboard joint.
(b) Check that the inboard joint slides smoothly in the
thrust direction.
(c) Check that there is no remarkable play in the radial
direction of the inboard ...
GCWR, TWR and Unbraked TWR
Confirm that the gross trailer weight, gross combination weight, gross
vehicle weight, gross axle weight and tongue weight are all within the
limits.
GCWR*
2WD models: 8900 lb. (4037 kg)
AWD models: 8990 lb. (4078 kg)
TWR*
3500 lb. (1588 kg)
Unbraked TWR*
1000 lb. (454 kg)
*: These models ...
Master Error
DTC 01-DF Master Error
DESCRIPTION
DTC No.
DTC Detection Condition
Trouble Area
01-DF
*1
The device with a display fails and the master is
switched to the audio device.
A communication error between sub-master (radio
receiver) and ...
