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2. RAIN SENSOR OPERATION
The rain sensor is installed on the specific heat treated windshield that has minimum 13% of
transmittance rate with specified intensity of radiation. It is installed on the glass with a adhesive of
Sorepa.
It communicates with STICS and makes the wipers to operate automatically under the rain sensing
mode (multifunction switch wiper: AUTO mode).
The emitting section of the rain sensor unit emits infrared rays against the windshield and then detects
the amount of rain drops by receiving reflected rays with photodiode.
The sensing section on the windshield is located just above the center point between LED and
photodiode.
Components and functions of the rain sensor unit
Unit latch
Rain
sensor unit
PCB assembly and
emitter lens
Emitter lens
The LED emits the infrared
rays is located at bottom and
the lens guides the infrared
rays to target point.
Receiver lens
The receiver lens guides the
reflected infrared rays from
windshield to photodiode.
Housing and
receiver lens
Housing and PCB
Rear
Front
Rain sensor unit (including cover)
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08-6
1) Rain Sensor Coupled Wiper
▶ System layout
This vehicle has a different wiper control logic compared to other models. As shown in the system
diagram, the rain sensor unit does not control wiper directly. The rain sensor unit sends infrared rays
signal through LED and then receives it with photo diode and then sends the returned signal to STICS
and the STICS controls the wipers directly.
For more details, refer to rain sensing wiper section in this manual.
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▶ Rain sensing operation point
The wiper relay is turned on and the wiper motor runs one cycle when the ignition key is turned to
“ON” position (while the wiper switch is in “AUTO” position).
The wiper relay (LO) is turned on and the wiper motor runs one cycle when changing the wiper
switch to “AUTO” position from any other positions (while the ignition key is in “ON”
position). When the wiper switch is turned to “AUTO” position again from other positions,
the system drives the wiper relay (LO) to run the wiper motor one cycle only when the rain sensor
detects the “Rain Detected” signal. 1)
2)
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08-8
The wiper relay is turned on and the wiper motor runs one cycle when the volume sensitivity is
increased (ex: from 0 to 1) (while the ignition key is in “ON” position, the wiper switch is in
“AUTO” position, and the wiper motor is in “Parked” position). However, the wiper motor can
be operated only when the rain sensor detects the “Rain Detected” signal.
▶ Rain sensing sensitivity control
If the volume sensitivity is changed more than 2 stages within 2 seconds, the wiper motor runs only
one cycle. *
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The wiper system continuously outputs the parking signal of current sensitivity when the parking
terminal is grounded (while the ignition key is in “ON” position and the wiper switch is in
“AUTO” position). 1)
※ The wiper motor runs only when the rain sensor requires.
When the parking terminal is fixed to IGN (HIGH), the wiper system outputs the operating signal of
current sensitivity for 2 seconds, then continuously outputs the parking signal of current sensitivity. 2)
※ The wiper motor runs only when the rain sensor requires.
▶ Wiper operation when the wiper parking terminal is grounded
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08-10
The wiper relay (LO) is turned on and the wiper motor runs one cycle when the wiper sensitivity is
changed to 2 from 3 during receiving the malfunction signal (1) from the rain sensor. However, the
wiper motor can be operated only when the rain sensor detects the "Rain Detected" signal. 1)
If the volume sensitivity is changed more than 2 stages within 2 seconds, the wiper motor runs
only one cycle. ▶ Defective rain sensor
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The wiper relay (LO) is turned on and the wiper motor runs one cycle when the wiper sensitivity is
changed to 2 from 1 during receiving the malfunction signal (3) from the rain sensor (while the
ignition key is in “ON” position and the wiper switch is in “AUTO” position). Also, the wiper
relay (LO) is turned on and the wiper motor runs one cycle when the wiper sensitivity is changed to
2 from 1 during receiving the ground fixed or IGN fixed signal from the rain sensor. 3)
The wiper relay (LO) is turned on and the wiper motor runs one cycle when the wiper sensitivity is
changed to 3 from 4 during receiving the malfunction signal (2) from the rain sensor (while the
ignition key is in “ON” position and the wiper switch is in “AUTO” position). 2)
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4. FUNCTIONS OF RAIN SENSOR
1) Windshield Glass and Coupler Attachment
Check the outer windshield surface of sensing area for wear, damage and scratch. The sensor is able
to compensate the wear up to a specific level. Check the coupler attached surface of windshield for
porosity. If the porosity exists, the sensor cannot function properly.
2) Recognition of AUTO Mode
3) Instant Wipe Function
When the variable resistance knob on the multifunction wiper switch is turned by each 1 stage from
low sensitivity (S mark) to high sensitivity (F mark), the wiper operates one cycle.
And, the wiper also operates during raining up to 5 minutes after rain stops.When the engine is started with the wiper switch “AUTO” position, the wiper operates one
cycle to remind a driver that the wiper switch is in “AUTO” position.
When the wi
per switch is turned to “AUTO” from OFF, the wiper operates one cycle. It always
operates one cycle for the initial operation, however, the wiper does not operate afterwards to
prevent the wiper blade wear if not raining when turning the wiper switch to “AUTO” from
“OFF”. However, the wiper operates up to 5 minutes after rain stops.
If this function does not occur, check No. 2 terminal on the rain sensor. If any defective cannot be
found, check the wiper relay (LOW) for defective. 1.
2.
3.If the installed wiper brushes are out of specification (size and length), the rain sensing area
cannot be fully wiped. In this case, the rain sensor’s sensitivity could be decreased and
the wipers are not properly operated. - The followings are the detailed description of the functions and operations of the rain sensing wiper
control.
As described, the STICS recognizes the wiper switch “AUTO” position. If there are not any
problem, go to diagnosis mode in STICS and check the terminal that receives signal from wiper
and communication lines between rain sensor unit and STICS. -
When the variable resistance knob is rotated by 4 stage from 0 stage without stopping, the wiper
operates one cycle. The wiper operates one cycle when changing the wiping stage (0 →
1, 1 → 2, 2 → 3). -