On Board Diagnostic - System Description - Wiper and Washer Systems (avant) Audi A4 B8

WIPER AND WASHER SYSTEMS GENERAL INFORMATION

General Information and Components

The wiper systems only work with terminal 15.

The rain sensor is activated when the windshield wiper/washer intermittent switch -E22- is set to Intermittent wiping.

The length of the pause between the wiping depend on the vehicle speed.

WINDSHIELD WIPERS WITHOUT RAIN SENSOR

General Information and Components

1. Wiper Motor Control Module -J400
2. Vehicle Electrical System Control Module -J519
3. Steering Column Electronic Systems Control Module -J527
4. Front Hood Switch -F266
5. Windshield Wiper/Washer Switch -E22

Function

Scheme 126

The steering column electronic systems control module reads the position of the windshield wiper/washer intermittent switch. The following switch positions are possible

1. Interval Wiping
2. Slow or Fast Wiping
3. One-Touch Wiping

The steering column electronic systems control module the windshield wiping information to the vehicle electrical system control module via the CAN-bus Comfort. The vehicle electrical system control module (master control module) sends the information to the windshield wiper motor control module (LIN slave control module). The windshield wiper motor control module then starts the wiping action.

Service Information

The wipers must be in the Service position in order to replace the wiper blades. Refer to the Owner's Manual. This is also possible using the Car menu in the MMI.

Opening the hood will immediately stop the windshield wipers. If the hood contact should be faulty, the windshield wipers will work while the vehicle is moving (emergency wiping).

As soon as the ignition is turned off, the windshield wiper/washer intermittent switch will stop and the wipers will go back to the 0 position.

WINDSHIELD WIPERS WITH RAIN SENSOR

General Information and Components

1. Rain/Light Recognition Sensor -G397
2. Wiper Motor Control Module -J400
3. Vehicle Electrical System Control Module -J519
4. Steering Column Electronic Systems Control Module -J527
5. Front Hood Switch -F266
6. Windshield Wiper/Washer Switch -E22

Rain/Light Recognition Sensor General Information

The rain/light recognition sensor must be coded when a new windshield is installed.

It is not recommended to perform any windshield repairs near or around the rain/light recognition sensor.

It is not necessary to replace the rain/light recognition sensor if the windshield is being replaced.

If the windshield glass gets covered with dirt, insects, salt or heavy dew, the rain/light recognition sensor may interpret these as being rain drops and start the wipers. Car wax can also coat the windshield glass and interfere with the function of the rain/light recognition sensor.

The sensitivity of the rain sensor can be set using the interval levels.

1. Interval 1 = lowest sensitivity
2. Interval 4 = highest sensitivity

Functional Requirements

1. Interval function turned on.
2. The rain/light recognition sensor recognizes moisture on the windshield.

Function

1. The Rain/Light Recognition Sensor -G397- measures how much of the windshield is covered with moisture.
2. The Vehicle Electrical System Control Module -J519- (master control module) sends the information to the windshield wiper motor control module.
3. The Windshield Wiper Motor Control Module -J400- then turns on the wiper motor and transmits the calculated wiper speed. 7 speeds are possible.
4. The Vehicle Electrical System Control Module -J519- turns on the low beam headlamps if the vehicle has automatic headlamp control.

Service Information

Should the rain/light recognition sensor be faulty, then the windshield wiper will function as it does in interval wiping.

The rain/light recognition sensor must be coded in the vehicle electrical system control module.

It is not possible to deactivate the rain/light recognition sensor. The automatic headlamp control will stop working if the automatic headlamp control rain/light recognition sensor is disconnected and the windshield wipers will work as they normally do in the interval setting.

Opening the hood will immediately stop the windshield wipers. The vehicle electrical system control module reads the position of the hood directly from the front hood switch.

REAR WINDOW WIPERS

General Information and Components

1. Windshield Wiper/Washer Switch -E22
2. Transmission Range Gear Recognition Switch -F208- (manual transmission)
3. Rear Window Wiper Motor -V12
4. Vehicle Electrical System Control Module -J519
5. Steering Column Electronic Systems Control Module -J527

Function

For information regarding wiping when washing the rear window, refer to REAR WINDOW WASHING .

Rear Window Wiping When Reverse Gear is Engaged

The rear window wiping in reverse gear works when the windshield wiping - reverse gear function is activated. This provides the driver with a clear view when driving in reverse.

For a detailed explanation of the windshield wiper function with and without a rain/light recognition sensor, refer to WINDSHIELD WIPERS WITHOUT RAIN SENSOR and to WINDSHIELD WIPERS WITH RAIN SENSOR .

1. The windshield wiping information is sent from the steering column electronic systems control module to the vehicle electrical system control module via the CAN-bus Comfort.

1. If the windshield wiping function is automatically sent via the rain/light recognition sensor, the vehicle electrical system control module will evaluate the current wiping status via the LIN-bus to determine if the wiper is working at that moment.
2. If the vehicle has a manual transmission, the vehicle electrical system control module receives the information directly from the transmission range gear recognition switch. If the vehicle has an automatic transmission, the vehicle electrical system control module receives this information from the transmission control module via the CAN-bus.

1. When reverse gear is engaged for a defined time, the vehicle electrical system control module will turn on the rear window wiper motor. The rear window wiper motor will work in regular intervals as along as reverse gear is engaged.

HEADLAMP WASHER SYSTEM

General Information and Components

The headlamp washer system turns on automatically when the low beam headlamps are on.

All Xenon headlamps have the headlamp washer system. The headlamp washer pump -V11- is another component.

Function

The headlamp washer system turns on when

1. The low beam headlamps are on.
2. Windshield wiping is turned on by the windshield wiper/washer intermittent switch -E22-.

The headlamp washer system is turned on the first time the windshield wiper switch is turned on and the low beam headlamps are on.

The second time automatic wiping is used, the headlamp washer system will turn on as long as the windshield wiper switch is operated for at least 2 seconds.

The vehicle electrical system control module -J519- turns on the headlamp washer pump.

The water stream will not be exact while the spray nozzles move in and out. The water pressure is what moves the spray nozzles out of the bumper. When the pressure decreases the spray nozzles return into the bumper.

Service Information

1. The headlamp washer system will not work if there is not enough washer fluid in the reservoir. Only the windshield and rear window washing will work.
2. The headlamp washer system function can be checked using a actuator test in the vehicle electrical system control module.
3. The headlamp washer system is coded in the vehicle electrical system control module.

WINDSHIELD WASHERS

General Information and Components

1. Wiper Motor Control Module -J400
2. Headlamp Washer System Pump -V11
3. Windshield Washer Pump -V5
4. Vehicle Electrical System Control Module -J519
5. Steering Column Electronic Systems Control Module -J527
6. Windshield Wiper/Washer Switch -E22

Function

Windshield washing starts when the windshield wiper/washer intermittent switch is pulled.

1. The windshield washing information is sent from the steering column electronic systems control module to the vehicle electrical system control module via the CAN-bus Comfort.
2. As long as the windshield wiper/washer intermittent switch is pulled, the vehicle electrical system control module will operate the windshield washer pump (with two washer pumps the driving direction determines the windshield washing). The washer fluid sprays onto the windshield.
3. At the same time the vehicle electrical system control module will send the message >>windshield washing<< to the windshield wiper motor control module via the LIN-bus. After a slight delay, the windshield wiper motor will start the wipers. The windshield wiper motor is integrated in the windshield wiper motor control module.
4. If the driving lamps are on, the vehicle electrical system control module will turn on the headlamp washer pump (special equipment). Refer to «HEADLAMP WASHER SYSTEM»(/audi/a4/b8-2007-2012/remont/wiperwasher-systems/#on-board-diagnostic-system-description-wiper-and-washer-systems-avant__headlamp-washer-system) .

Service Information

The functionality can be tested with an actuator test in the vehicle electrical system control module.

REAR WINDOW WASHING

General Information and Components

1. Windshield Wiper/Washer Switch -E22
2. Windshield Washer Pump -V5- (two washer pumps)
3. Rear Window Wiper Motor -V12
4. Vehicle Electrical System Control Module -J519
5. Steering Column Electronic Systems Control Module -J527

Function

Rear window washing starts when the windshield wiper/washer intermittent switch is pulled.

Process

1. The steering column electronic systems control module recognizes the position of the windshield wiper switch and sends the message to the vehicle electrical system control module via the CAN-bus Comfort.
2. As long as the windshield wiper/washer intermittent switch is held pulled forward, the vehicle electrical system control module will operate the windshield washer pump for the rear window. The washer fluid sprays onto the rear window.
3. After a slight delay, the vehicle electrical system control module will start the rear window wiper motor to start the wiping. The wiping will continue as long as the windshield wiper/washer intermittent switch if held pushed forward and for a few seconds after the switch is released.

Service Information

The rear window washing functionality can be checked using an actuator test vehicle electrical system control module.

SPRAY NOZZLE HEATING

There are two heating elements (left washer nozzle heater -Z20- and right washer nozzle heater -Z21-). Terminal 75 provides the heating elements with electricity. The heating elements are also protected by a fuse.

The heating elements are on whenever the ignition is turned on, except when starting the engine

A005A4033-030110

See also:
• REAR WINDOW WASHING
• WINDSHIELD WIPERS WITHOUT RAIN SENSOR
• WINDSHIELD WIPERS WITH RAIN SENSOR
• HEADLAMP WASHER SYSTEM