Toyota Sienna Service Manual: Laser Sensor Power Source Circuit
DESCRIPTION
This circuit provides power to the laser sensor. The laser sensor emits radio waves towards an object in front and measures the distance and direction of the object by receiving the beam reflections. Based on the reflections, the sensor calculates the difference in speed between the vehicle and the object in front.
This data is transmitted to the distance control ECU. The ECM recognizes the laser sensor via terminals LGND. If an open circuit occurs in the wire harness between terminals LGND, the ECM cannot recognize the laser sensor. The ECM will stop the control of the vehicle-to-vehicle distance control mode and only the constant speed control mode can be used.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 CHECK DISTANCE CONTROL ECU (IGB VOLTAGE)
- Disconnect the L1 laser sensor connector.
- Measure the voltage according to the value(s) in the table below.
Standard voltage
2 CHECK HARNESS AND CONNECTOR (LASER SENSOR - ECM AND BODY GROUND)
- Disconnect the E4 connector from the ECM.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
3 CHECK HARNESS AND CONNECTOR (LASER SENSOR - DISTANCE CONTROL ECU)
- Disconnect the D2 distance control ECU connector.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
REPLACE DISTANCE CONTROL ECU
Distance Control Switch Circuit
DESCRIPTION
The distance control switch sets the vehicle-to-vehicle distance mode. The
distance control switch is
installed in the steering pad switch. The vehicle-to-vehicle distance set value
...
Wiper Signal Circuit
DESCRIPTION
The distance control ECU detects wiper operation. If the windshield wipers
operate in the HI or LO mode,
the cruise control is canceled and the warning sound "pong" is emitte ...
Other materials:
Problem symptoms table
SLIDE DOOR CLOSER SYSTEM
Symptom
Suspected Area
Slide door closer LH does not operate (*1)
ECU-B fuse
Power slide door lock assembly LH
Power slide door ECU LH
Wire harness
Slide door closer RH does not operate
ECU-B ...
Diagnostic trouble code chart
1. DTCS FOR AIRBAG SYSTEM
If a malfunction code is displayed during the DTC check,
check the circuit listed for the code in the table below
(Proceed to the page listed for that circuit).
HINT:
When the SRS warning light remains on and the DTC
output is the normal system code, a volta ...
Master Reset/ Voice Processing Device ON Error
DTC 01-DD Master Reset
DTC 01-E1 Voice Processing Device ON
DESCRIPTION
DTC No.
DTC Detection Condition
Trouble Area
01-DD
*1
The device that should be the master has been
disconnected after the engine starts.
Radio and navigation assembly po ...
