Wiper / Washer (Diagnostics & Circuit Tests): Other Lexus LX J200

FAIL-SAFE CHART

1. FRONT WIPER SYSTEM When the wiper switch is in any position other than "OFF" and the blades are frozen, a malfunction is detected by the windshield wiper ECU and the wiper operation is stopped. HINT: Recovery condition: the engine switch is turned off. When the rain sensor is broken and the wiper switch is in the AUTO position, the front wiper system is changed to the intermittent mode. HINT: Recovery condition: the signal level error cancellation is received from the rain sensor. When the rain sensor overheats and the front wiper is in the HI operation mode, the front wiper system is changed to the LO operation mode. HINT: Recovery condition: the engine switch is turned off or the wiper switch is turned to any position other than INT or LO. When the windshield wiper ECU malfunctions, the front wiper system can be set to the HI operation mode with the combination switch only. HINT: Recovery condition: the windshield wiper ECU returns to normal.

PROCEDURE

1. CHECK WIPER Check the symptoms of the wiper. Check if the causes of the symptoms are any of the following conditions shown in the charts. 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 more 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 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 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 NG --> See step 2 OK --> END
2. CHECK WIPER OPERATION Set the windshield wiper switch to the LO and HI setting, and check that the wipers operate normally. OK Wipers operate normally NG --> See step 11 OK: Go to next step
3. CHECK WINDSHIELD WIPER SWITCH Set the windshield wiper switch to AUTO, and check the problem symptom. RESULT Result Proceed to It is raining but wiper does not operate A It is not raining but wiper operates B B --> See step 15 A: Go to next step
4. CHECK OPERATION OF WIPER Check operation of the wipers. RESULT Result Proceed to Wiper does not operate normally A It is raining but wiper does not operate B B --> See step 15 A: Go to next step
5. CHECK WIPER RUBBER Activate the washer and check the wiping ability of the wiper. OK No residue after wipe NG --> See step 12 OK: Go to next step
6. READ VALUE USING TECHSTREAM (COMBINATION SWITCH) Using the Techstream, read the Data List. BODY NO. 5 Tester Display Measurement Item / Range Normal Condition Diagnostic Note 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. NG --> See step 16 OK: Go to next step
7. CHECK RAIN SENSOR 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 NG --> See step 13 OK: Go to next step
8. READ VALUE USING TECHSTREAM (RAIN SENSOR) Using the Techstream, read the Data List. 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. NG --> See step 14 OK: Go to next step
9. CHECK RAIN SENSOR 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. STANDARD MEASUREMENT Area Specified Condition A 7 mm (0.276 in.) B 22 mm (0.866 in.) C 16.6 mm (0.654 in.) D 26.6 mm (1.05 in.) E 12 mm (0.472 in.) RESULT Result Proceed to Wiper does not operate A Wiper operates normally B Any other operation C C --> See step 17 B --> END A --> See step 10
10. REPLACE RAIN SENSOR. Refer to REMOVAL
11. PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE
12. REPLACE WIPER RUBBER. Refer to REMOVAL
13. REPLACE RAIN SENSOR TAPE. Refer to REMOVAL
14. REPLACE RAIN SENSOR. Refer to REMOVAL
15. CHECK RAIN SENSOR 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 NG --> See step 13 OK --> See step 14
16. REPLACE WINDSHIELD WIPER SWITCH. Refer to REMOVAL
17. REPLACE WINDSHIELD WIPER ECU. Refer to REMOVAL