Rain sensor

Components and Component Location

Components

Description and Operation

Description

1. Wiper Control System: When the "AUTO" signal is received from the multifunction switch on the right, the built-in rain sensor detects the amount of precipitation. The sensor is installed inside the upper part of the windshield to control the wiper motor. This system automatically controls the duration and speed of wiper operation according to the measured amount of precipitation, even if the driver does not operate the wiper switch.

   

Functions and Operation Principles

1. 1
   Rain Detection: Light (beam) emitted by the LEDs is fully reflected at the outer surface of the windshield and returned to the photodiodes. When water is present on the outer surface of the windshield, the light is optically separated and partially reflected, and the remaining brightness is measured by the photodiodes. Water remaining on the windshield prevents the light from being fully reflected. The loss of brightness caused by this indicates how wet the glass surface is.
2. 2
   Dust on the measuring surface and other surfaces in the beam path (surface of the LEDs and photodiodes, fiber optics, bracket and glass surface in the area of the windshield joint) weakens the received light.
3. 3
   Movement of the windshield and bracket
4. 4
   Movement of the bracket due to vibration
5. 5
   Damaged wiper blade

If the integrated rain sensor is not operating or is malfunctioning, the driver must operate the wiper switch manually.

1. 1
   Rain Sensor Operating Condition

   Operation Mode	Operation
   Direct Mode	This is the normal operating state of the built-in rain sensor when the wiper switch is in the "AUTO" position and the sensor has detected a dry windshield. Based on this state, the built-in rain sensor determines the wiper operating mode according to the precipitation and its duration.
   Intermittent Mode	The built-in rain sensor activates intermittent mode when the wiper operates more than two times in succession with a pause of 0.5 - 5 seconds.
   Low speed	Wipers operate continuously at low speed
   High speed	Wipers operate continuously at high speed

2. 2
   When ice or foreign material is present in the detection area, the integrated rain sensor cannot correctly recognize the operating conditions.
3. 3
   Rain sensor

   Special Condition	Operation Based on Special Condition Detection
   Hesitation	When the built-in rain sensor detects a high level of water (spray) in direct or intermittent mode, the system switches from park mode to high speed. Then wiping is performed once at high speed and once more at low speed. If the precipitation condition does not change after wiping, it returns to the original state (direct or intermittent).
   Smearing	Smearing is a thin oil film that dries quickly and occurs when a small amount of precipitation is wiped by a dirty or worn wiper blade. The operating signal should not be output when smearing occurs in direct or intermittent mode.
   Mud	If no change is detected after wiping, the built-in rain sensor determines that the windshield is contaminated. In this condition, the operating signal should not be output. If the windshield becomes clean (for example, by washer fluid), the built-in rain sensor returns to normal.
   Washer Fluid	The built-in rain sensor does not respond to washer fluid during washing mode. In other words, the wiping speed does not change even if washer fluid is sprayed (automatic operation of the washer pump does not affect the operation of the built-in rain sensor).

Repair Procedures

Removal

Do not damage or touch the silicone (coupling medium). Be careful not to contaminate the silicone with foreign substances, dust, etc. Be careful, as the silicone may be damaged if you try to separate the rain sensor by force.

Dust or foreign substances on the rain sensor may affect rain sensor operation. To ensure accurate rain sensor operation, protect the sensor surface with a protective cover until the sensor is installed on the bracket. The adhesive pad on the rain sensor surface is sticky, and the adhesive pad may stick to the windshield during use depending on environmental conditions. Therefore, it may be damaged when you try to remove the rain sensor from the windshield by force. Be careful when separating it from the windshield.

1. 1
   Remove the rain sensor covers (A) and (B).

   

2. 2
   To release the latch, pull the latch aside using the opening in the cover with a small flat-blade screwdriver.

   

3. 3
   Remove the rain sensor.

   1. Insert a small flat-blade screwdriver (-) into the hole at the bottom (B) or top (A), between the rain sensor and the bracket.
   2. Slowly pull the rain sensor up and down in the vertical direction of the glass, then slowly remove the rain sensor from the windshield without damaging the silicone on the sensor.

   

   It may be damaged when trying to remove the rain sensor from the windshield by force. Be careful when separating it from the windshield. When separating the silicone under high temperature, it can be easily damaged due to the strength of the silicone adhesive. Remove the silicone in a cool place.

4. 4
   Disconnect the harness connector (B) from the rain sensor by inserting a small flat-blade screwdriver (A) into the opening.

   

Installation

Check the operation of the rain sensor and light sensor before installation. Inspect the sensor for damage to the silicone. Check that the rain sensor connector is fully connected. Check that the rain sensor and bracket are tightened correctly. Check that there are no foreign objects in the sensor installation area. Calibrate the sensitivity of the switch if the automatic wiping operation is insensitive or too sensitive. If the rain sensor silicone is normal or slightly damaged, as shown in the illustrations below, it can be reused. Normal Damage within 1.5 mm from the outer edge If the rain sensor silicone is damaged, as shown in the illustrations below, replace it with new silicone. Foreign matter Fingerprint Damage Damage If the rain sensor silicone is damaged, replace it as shown below. 1) Completely remove the damaged silicone gel pad from the lens plate. Be careful not to damage or contaminate the surface of the lens plate during removal. 2) Attach a new silicone gel pad after removing the silicone paper (A), then remove the clear film (B). When attaching the silicone gel pad to the sensor, be careful not to contaminate It is very important that the silicone (coupling pad) is fully pressed against the windshield and bonded without air bubbles. When replacing a damaged windshield, you can use the undamaged existing rain sensor. The windshield must be clean and free of contamination or foreign matter.

1. 1
   Connect the rain sensor connector.
2. 2
   Press one of the spring arm latches (A) down until it clicks into place. Then press the latch of the second spring arm (B) to hold the sensor in the correct position.

   

   Do not snap both spring clips at the same time. An improperly installed snap-fit connection may cause the rain/light sensor to malfunction.