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:
Description of initialization
(a) Perform initialization in the following cases:
Before delivery of a new vehicle.
After replacement of the tire pressure warning
ECU*.
After replacement of the tire pressure warning
valve and transmitter.
Specified tire pressure changes depending on
the size or type of the tire.
...
Operation check
1. DOOR LOCK FAIL-SAFE
When a malfunction in the door control switch
(manual switch, interlocked with key operation) has
been detected, door lock/unlock operation becomes
disabled.
2. CHECK ELECTRICAL DOOR LOCK OPERATION
Check the basic function.
Check that a ...
Power Slide Door Warning Buzzer RH does not Sound
DESCRIPTION
The power slide door system uses warning buzzers built into RH
slide doors respectively. Each buzzer
has 2 ways of sounding that are used differently according to the
situations:
When all the following conditions are met, the warning buzzer sounds at
a cycle of ...