Wiper and Washer Systems: Description and Operation

OPERATION

Windshield Low-speed (and High-speed) Wiper Operation
- If the wiper switch is turned to the "LO" position with the ignition switch at the "ACC" or "ON" position, the column switch sends a low-speed wiper ON and high-speed wiper OFF signals to the front-ECU. This turns the wiper signal on and the wiper speed switching relay off (low-speed), causing the wipers to operate at low-speed.
- If the wiper switch is turned to the "HI" position, the column switch sends a low-speed wiper OFF and high-speed wiper ON signals to the front ECU. This turns both the wiper signal and the wiper speed switching relay on (high-speed), causing the wipers to operate at high-speed.

Windshield Intermittent Wiper Operation
- The ETACS-ECU calculates the wiper operation interval according to the voltage signal sent from the column switch. Then the ETACS-ECU sends a signal to the front-ECU. The front-ECU determines the wiper operation interval and turns on the wiper relay signal. This causes the wiper auto stop relay to turn on. Then the wiper auto stop relay will turn off after the wipers reach the park position. This causes the wiper signal relay and then the wipers to turn off. If the wiper signal relay remains off for the wiper operation interval, the relay turns on again, causing the wipers to operate in intermittent mode.

Windshield Mist Wiper Operation
- If the wiper switch is turned to the "MIST" position with the ignition switch at "ACC" or "ON" position, the mist wiper high-speed operation signal is sent to the front-ECU. This signal turns on the wiper speed switching relay, causing the wipers to work at high-speed while the mist switch is on.
- While the mist wiper switch remains turned on when the intermittent mode is still working, the wipers work as the mist wiper. However, the wipers return to the intermittent mode again when the wiper auto stop signal turns on after the mist wiper switch is turned off.

Windshield Washer Operation
- If the wiper switch is turned to the "WASHER" position with the ignition switch at "ACC" or "ON" position, the washer ON signal is sent to the front-ECU, causing the wiper signal to turn on after 0.6 seconds. After the washer switch signal turns off, the wiper signal turns off in three seconds. If the wiper switch is turned the "WASHER" position while the wiper is at intermittent mode, the washer works for that period when the washer switch remains on. Then the wipers return to the intermittent mode.