Wiper System / Washer System (Diagnostics & Circuit Tests): Overview Lexus GX J150

SYSTEM DESCRIPTION

1. FRONT WIPER AND WASHER SYSTEM DESCRIPTION Each ECU and motor receive signals from the windshield wiper switch to operate the system. The auto wiper system (rain sensing semi-auto wiper) includes functions, such as the auto wiper function and vehicle speed switching function, that operate the wipers intermittently in response to the amount of rain.
2. FUNCTION OF MAIN COMPONENTS The wiper and washer system consists of the following components: Component Outline Windshield wiper switch assembly Sends signals to each ECU and controls all the functions of the auto wiper system (rain sensing semi-auto wiper). Main body ECU (Multiplex network body ECU) Outputs the display dimmer signal (daytime and nighttime signal) to the windshield wiper switch. When the glass hatch is open, the rear wiper system cuts off the power supply to prevent the rear wiper and rear washer from operating. Sends headlight low beam illumination signals to the headlight cleaner relay. Combination meter assembly Outputs the vehicle speed signal to the windshield wiper switch. Rain sensor Detects the amount of rain and outputs a wiper operation request signal to the windshield wiper switch via LIN communication. Windshield wiper motor and pump assembly Operates the front wiper blades according to windshield wiper switch control.
3. SYSTEM FUNCTION The wiper and washer system has the following functions: Function Outline Auto wiper function When the windshield wiper switch is set to AUTO, the rain sensor detects the amount of rain and in response sends optimally timed wiper operation request signals (LO or HI) via LIN communication to the windshield wiper switch, which operates the windshield wiper motor and pump assembly. The windshield wiper switch receives the wiper operation request signal and changes the wiper operation to intermittent timing by operating the windshield wiper motor and pump assembly. If water splashing or a sudden increase in the amount of rain is detected, the wipers are operated continuously at HI speed. Rain sensing function The rain sensing function controls the wiper timing in accordance with the amount of raindrops that strike the windshield when the wiper switch is in AUTO. The windshield wiper switch assembly controls the timing based on the signal from the rain sensor. Vehicle speed switching function When the vehicle is stopped and the wiper switch is moved to LO from any position other than LO, the wipers operate 3 times at LO speed and then automatically change to intermittent operation with an interval of approximately 2.5 seconds. When the vehicle stops moving with the windshield wiper switch set to LO, the wipers operate 2 times at LO speed and then change to intermittent operation with an interval of approximately 2.5 seconds. When the vehicle starts moving during intermittent wiper operation, the wiper operation automatically returns to continuous operation at LO speed. If the sensitivity adjustment switch is set to FAST, continuous wiper operation at LO speed is possible even when the vehicle is stopped. Vehicle speed response intermittent timing adjustment function When the windshield wiper switch is set to AUTO, if there is a rain sensor malfunction and rain sensing semi-auto wiper control cannot be performed, the wipers operate intermittently in response to the vehicle speed. If the sensitivity adjustment switch is operated, the interval for intermittent operation can be adjusted from approximately 1.5 seconds to approximately 12.5 seconds, and the interval changes among 3 levels within the adjustment range in response to the vehicle speed while the vehicle is being driven. Washer-linked wiper function When the windshield wiper switch is set to off or auto and the washer switch is turned on for approximately 0.3 seconds or more, the wipers start operating at low speed at the same time as the washer fluid is sprayed. The wipers operate three times at low speed after the washer switch is turned off. Headlight cleaner function* The headlight cleaner system operates when the headlight cleaner switch is pushed on. The headlight cleaner system also operates when the front washer switch is first operated with the headlights on. Fail-safe The windshield wiper switch performs wiper control when a malfunction occurs in LIN communication, any of the switches of the windshield wiper switch assembly, etc. *: w/ Headlight Cleaner System

OPERATION CHECK

1. RAIN SENSOR FUNCTION CHECK Turn the engine switch on (IG) and set the windshield wiper switch to AUTO. Spray water on the windshield in an area close to the rain sensor and check that the wipers operate once.

DESCRIPTION

The headlight cleaner control relay receives the windshield washer operation signal.

Scheme 126

Scheme 127

1. CHECK OPERATION Check the operation of the front wiper and washer system. Refer to «SYSTEM DESCRIPTION»(ref-524359-S25165322032013012800000) . OK Front wiper and washer system operates normally. NG --> See step 4 OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (WINDSHIELD WIPER SWITCH ASSEMBLY - HEADLIGHT CLEANER CONTROL RELAY) Disconnect the A32 headlight cleaner control relay connector. Measure the voltage according to the value(s) in the table below. Standard Voltage Tester Connection Switch Condition Specified Condition A32-5 (FRWA) - Body ground Engine switch on (IG), front washer switch on Below 1 V A32-5 (FRWA) - Body ground Engine switch on (IG), front washer switch off 11 to 14 V TEXT IN ILLUSTRATION *a Front view of wire harness connector (to Headlight Cleaner Control Relay) NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 3
3. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-524359-S19365344262013012800000)
4. GO TO PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-524359-S19365344262013012800000)

The headlight cleaner control relay detects the low beam headlights status.

Scheme 128

When the glass hatch is open, the rear wiper system cuts off the power supply to prevent the rear wiper and rear washer from operating.

Scheme 129

This circuit detects the conditions (on or off) of the headlight cleaner switch assembly.

Scheme 130

Scheme 131

1. INSPECT HEADLIGHT CLEANER SWITCH ASSEMBLY Remove the headlight cleaner switch assembly. Refer to «INSPECTION»(ref-524281-S05893292242013012800000) . Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Switch Condition Specified Condition 5 - 8 Headlight cleaner switch on Below 1 ohms 5 - 8 Headlight cleaner switch off 10 kohms or higher NG --> See step 4 OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (HEADLIGHT CLEANER SWITCH ASSEMBLY - HEADLIGHT CLEANER CONTROL RELAY AND MAIN BODY ECU) Disconnect the G54 headlight cleaner switch connector. Disconnect the A32 headlight cleaner control relay connector. Remove the main body ECU. Refer to «REMOVAL»(ref-524305-S41918141882013012800000) . Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition G54-8 - A32-2 (H) Always Below 1 ohms G54-5 - A-15 (HRLY) Always Below 1 ohms G54-8 - Body ground Always 10 kohms or higher G54-5 - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 3
3. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-524359-S14912299002013012800000)
4. REPLACE HEADLIGHT CLEANER SWITCH ASSEMBLY. Refer to «REMOVAL»(ref-524281-S13704807932013012800000)

This circuit provides power to the headlight cleaner control relay.

The headlight cleaner control relay sends the signal from the headlight cleaner switch assembly, etc. to the headlight cleaner motor and pump assembly to operate the headlight cleaner system.

Scheme 132

When the volume of washer fluid decreases to below a certain level (when the level warning switch is turned on), the multi-information display warns the driver by displaying a message.

Scheme 133

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Scheme 135

1. READ VALUE USING TECHSTREAM (WASHER SWITCH) Use the Data List to check if the level warning switch assembly is functioning properly. Refer to «DATA LIST / ACTIVE TEST»(ref-524359-S14232081622013012800000) . COMBINATION METER Tester Display Measurement Item/Range Normal Condition Diagnostic Note Washer Switch Level warning switch / ON or OFF ON: Washer jar and tank empty OFF: Washer jar and tank full - OK On the Techstream screen, item changes between ON and OFF according to the above chart. NG --> See step 2 OK --> See step 5
2. INSPECT LEVEL WARNING SWITCH ASSEMBLY Remove the level warning switch assembly. Refer to «REMOVAL»(ref-524281-S27561528732013012800000) . Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition 1 - 2 Fluid volume is more than 830 cc (50.6 cu.in.) 10 kohms or higher 1 - 2 Fluid volume is less than 630 cc (38.4 cu.in.) Below 1 ohms HINT: When the fluid volume is between 630 and 830 cc (38.4 cu.in. and 50.6 cu.in.) the level warning switch may be on or off. NG --> See step 6 OK: Go to next step
3. CHECK WASHER WIRING ASSEMBLY Disconnect the A20 and A washer wiring assembly connectors. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A20-3 (S) - A-1 Always Below 1 ohms A20-6 (E) - A-2 Always Below 1 ohms A20-3 (S) - Body ground Always 10 kohms or higher A20-6 (E) - Body ground Always 10 kohms or higher NG --> REPLACE WASHER WIRING ASSEMBLY OK: Go to next step
4. CHECK HARNESS AND CONNECTOR (WASHER WIRING ASSEMBLY - COMBINATION METER ASSEMBLY AND BODY GROUND) Disconnect the A20 washer wiring assembly connector. Disconnect the G3 combination meter assembly connector. Measure the resistance according to the value(s) in the table below. Standard Resistance Tester Connection Condition Specified Condition A20-3 (S) - G3-34 (WLVL) Always Below 1 ohms A20-6 (E) - Body ground Always Below 1 ohms A20-3 (S) - Body ground Always 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS OR CONNECTOR OK --> See step 7
5. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE»(ref-524359-S19365344262013012800000)
6. REPLACE WASHER FLUID LEVEL WARNING SWITCH ASSEMBLY. Refer to «REMOVAL»(ref-524281-S27561528732013012800000)
7. REPLACE COMBINATION METER ASSEMBLY. Refer to «REMOVAL»(ref-524277-S08139366202013012800000)