WIPER AND WASHER SYSTEM (w/ Rain Sensor) Rain Sensor Circuit

DESCRIPTION

The auto wiper system adjusts the wiper speed to the optimum speed based on the amount of rain. The rain sensor mounted on the windshield detects rainfall. This system operates when the windshield wiper switch is set to AUTO. The rain sensor sensitivity can be adjusted with the rain sensor adjusting switch. Signals are sent to the windshield wiper ECU from the windshield wiper switch through the CAN line, and from the rains sensor through the LIN line. Based on these signals, the windshield wiper ECU operates the wiper and determines its operation speed.

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   CHECK WIPER

   
   

   1. Check the symptoms of the wiper. Check if the causes of the symptoms are any of the following conditions shown in the charts.

      Table 1. It is Raining but Wiper does not Operate

      Condition	Note
      Windshield wiper switch in position other than AUTO	Wiper only operates at AUTO setting
      Rain sensor temperature is -10°C (14°F) or less, or 70°C (158°F) or higher	To prevent improper operation, wiper does not operate when rain sensor temperature is -10°C (14°F) or less To prevent damage to rain sensor, wiper does not operate when outside temperature is 70°C (158°F) or more, or when interior temperature of sensor is 90°C (194°F) or more
      It is drizzling, or there is scattered rain	If rain droplets do not contact rain sensor, or rain droplets are very small, they are not detected

      Table 2. It is not Raining but Wiper Operates

      Condition	Note
      Condensation on windshield	Wiper may operate if condensation occurs in rain sensor detection area. If condensation recurs after rain sensor detection area is wiped, wiper operation may continue.
      Sun rays are strong	If sudden changes in light intensity occur, wiper may operate
      Sudden temperature changes	If sudden changes in temperature occur (A/C heater is used in winter, etc.), wiper may operate
      Object is contacting rain sensor	If inner mirror contacts or strikes rain sensor, wiper may operate
      Windshield wiper switch off by AUTO	Wiper operates 1 time after windshield wiper switch is turned off by AUTO

      Table 3. Wiper Operation is Irregular

      Condition	Note
      Wiper blade is deteriorated Windshield surface is oily	Rain sensor detects rain amount when wipers are operating. When rain is not completely wiped off by wipers, decrease in ability to detect amount of rain occurs.
      During scattered rain Heavy rain with large droplets	During scattered rain or when rain droplets are large, rain droplets contact the sensor intermittently, causing wiper operation to be irregular During heavy rain, it is difficult for sensor to learn "no rain" condition, causing wiper operation to be irregular
      Wiper volume is set to minimum	Minimum wiper volume setting is designed to be non-sensitive (for users who prefer non-sensitive operation), resulting in irregular wiper operation
      Problem with wiper motor position signal	When wiper motor position signal has chattering, wiper may operate excessively. During auto wiper operation inspection, if wiper operates several times, and replacement of rain sensor does not correct problem, wiper motor may be malfunctioning.

      OK
      Causes of symptoms are one or more of above conditions

   
   
   • OKClick here
   • NGClick here
2. Click here

   CHECK WIPER OPERATION

   
   

   1. Set the windshield wiper switch to the LO and HI setting, and check that the wipers operate normally.

      OK
      Wipers operate normally

   
   
   • OKClick here
   • NGClick here
3. Click here

   CHECK WINDSHIELD WIPER SWITCH

   
   

   1. Set the windshield wiper switch to AUTO, and check the problem symptom.

      Table 4. Result

      Result	Proceed to
      It is raining but wiper does not operate	A
      It is not raining but wiper operates	B

   
   
   • AClick here
   • BClick here
4. Click here

   CHECK OPERATION OF WIPER

   
   

   1. Check operation of the wipers.

      Table 5. Result

      Result	Proceed to
      Wiper does not operate normally	A
      It is raining but wiper does not operate	B

   
   
   • AClick here
   • BClick here
5. Click here

   CHECK WIPER RUBBER

   
   

   1. Activate the washer and check the wiping ability of the wiper.

      OK
      No residue after wipe

   
   
   • OKClick here
   • NGClick here
6. Click here

   READ VALUE USING INTELLIGENT TESTER (COMBINATION SWITCH)

   
   

   1. Check the Data List for proper functioning of the combination switch.

      Table 6. Combination Switch:

      Tester Display	Measurement Item / Range	Normal Condition	Diagnostic Note
      F Wiper AUTO Switch	Front wiper AUTO switch / ON or OFF	ON: Front wiper switch in AUTO position OFF: Wiper switch not in AUTO position	-

      OK
      Windshield wiper switch operates.

   
   
   • OKClick here
   • NGClick here
7. Click here

   CHECK RAIN SENSOR

   
   

   1. Check that the rain sensor is installed properly.

      OK
      When viewed from outside of vehicle, rain sensor tape is not peeling and has no air bubbles or dust on it, and sensor has not come off bracket

   
   
   • OKClick here
   • NGClick here
8. Click here

   READ VALUE USING INTELLIGENT TESTER (RAIN SENSOR)

   
   

   1. Check the Data List for proper functioning of the rain sensor.

      Table 7. Rain Sensor

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      Rain Sensor Cold	Rain sensor cold / COLD or OK	COLD: Front wiper switch in AUTO position OK: Wiper switch not in AUTO position	-
      Rain Sensor Hot	Rain sensor cold / HOT or OK	HOT: Front wiper switch in AUTO position OK: Wiper switch not in AUTO position	-

      OK
      Rain sensor operates.

   
   
   • OKClick here
   • NGClick here
9. Click here

   CHECK RAIN SENSOR

   
   
   1. 

      Set the windshield wiper switch to AUTO. Flatten the end of a cotton swab soaked with water so that it is 4 to 6 mm (0.157 to 0.236 in.) wide. Touch the swab to the rain sensor detection area and check that the wiper LO operation occurs once.

      Table 8. Result

      Result	Proceed to
      Wiper does not operate	A
      Wiper operates normally	B
      Any other operation	C

   
   
   • AClick here
   • BClick here
   • CClick here
10. Click here

    REPLACE RAIN SENSORClick here

11. Click here

    END

12. Click here

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLEClick here

13. Click here

    REPLACE WIPER RUBBERClick here

14. Click here

    REPLACE RAIN SENSOR TAPEClick here

15. Click here

    REPLACE RAIN SENSORClick here

16. Click here

    CHECK RAIN SENSOR

    
    

    1. Check that the rain sensor is installed properly.

       OK
       When viewed from outside of vehicle, rain sensor tape is not peeling and has no air bubbles or dust on it, and sensor has not come off bracket

    
    
    • OKClick here
    • NGClick here
17. Click here

    REPLACE WINDSHIELD WIPER SWITCH ASSEMBLYClick here

18. Click here

    REPLACE WINDSHIELD WIPER ECUClick here