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:
Front door lock
INSPECTION
1. INSPECT FRONT DOOR W/ MOTOR LOCK ASSEMBLY LH
Apply battery voltage to the door lock and check
operation of the motor.
OK
HINT:
If the result is not as specified, replace the door lock
assembly.
Measure the resistance according to the value(s) in
the table ...
Washer Signal Circuit
DESCRIPTION
The distance control ECU detects washer operation. The cruise control will be
cancelled by the distance
control ECU if the windshield wipers operate in the HI or LO mode. By detecting
washer operation, the
distance control ECU allows the cruise control to continue even when the
...
Removal
1. Remove no. 2 Air cleaner inlet (see page em-
28)
2. Remove air cleaner cap sub-assembly
(a) Disconnect the 3 vacuum hoses.
(b) Loosen the bolt, disconnect the 2 connectors, and
remove the 2 vacuum hoses.
(c) Remove the 2 bolts, air cleaner cap sub-assembly,
and air cleaner filt ...
