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:
Precaution
CAUTION:
The vehicle is equipped with a Supplemental Restraint
System (SRS). It consists of a driver airbag, front
passenger airbag, front seat side airbag, curtain shield
airbag, and front seat belt pretensioner. Failure to
carry out service operations in the correct sequence
co ...
Map Display Incomplete
INSPECTION PROCEDURE
1 CHECK MAP DISC
Check that the map disc is not deformed or cracked.
OK:
No deformations or cracks on map disc.
2 CHECK DISPLAY
Check that displays other than the navigation display are
complete.
OK:
No other incomplete displays are found.
REPLACE RADIO ...
ACIS Control Circuit
DESCRIPTION
This circuit opens and closes the Intake Air Control Valve (IACV) in response
to changes in the engine
load in order to increase the intake efficiency (ACIS: Acoustic Control
Induction System).
When the engine speed is between 0 and 4450 rpm and the throttle valve opening
angl ...
