General Information
WINDSHIELD WIPING/WASHING
- The GM III controls all of the windshield wiping/washer and headlight washing functions.
- Output control of the wiper motor is through the windshield wiper double contact relay. The relay is located in the engine compartment E-box and is tan in color.
- The system continues to have four wiping stages and four interval wiping speeds. The wiping stage inputs are coded signals through a two wire link with a combination of high/low inputs as on previous systems.
- The Windshield Wiping System can also be supplemented with the Rain Sensor system as optional equipment. The Rain Sensor detects rain drops on the windshield and automatically activates the wipers when the stalk switch is in the intermittent position.
Wiper Stalk Switch:
SINGLE: Holding the wiper switch down in the single position provides a ground signal to activate the slow speed circuit providing wiper operation until the switch is released.
INTERMITTENT: The intermittent wiping time inputs are provided by a potentiometer mounted in the wiper stalk switch.
WIPER TIME DELAYS (SECONDS) BASED ON SET POSITIONS 1 - 4
- The intermittent wiping intervals are dependent on the road speed.
- As road speed increases, the wiping interval delay is decreased.
SLOW (I) AND FAST (II): The stage I and stage II wiping speeds are also affected by road speed. The factory encoded settings are the same as previous systems:
- Stage I automatically switches to intermittent when the vehicle is stopped
- Stage II switches to stage I when stopped.
WINDSHIELD WASHING:
Pulling the Windshield Wiper Switch rearward closes the "wash" contact providing a switched ground input to the GM. The GM activates the windshield washer pump directly via a power output final stage transistor.
HEADLIGHT WASHING:
When the headlights are on, the headlight washer pump is activated with the first activation of the windshield washer pump. The GM recognizes headlights on via K bus signalling.
Within the same "on" cycle (ignition key has not been switched off), it is only activated again after five successive windshield washer cycles.
The GM provides a ground on the headlight washer relay control circuit providing pump operation. The relay is located in the e-box.
The X5 uses three separate washer pumps which are all easily accessible on the 7.8 liter washer fluid reservoir located in the engine compartment.
REAR WINDOW WIPER/WASHER SYSTEM
The tailgate window wiper/washer system is included in the scope of ZKE however is not controlled directly by the CM. The control electronics are integrated into the rear wiper motor assembly. It contains two hall sensors, one for monitoring park position and other for the end stop, or to signal reverse direction of the wiper motor.
The rear wiper system is operator controlled through the wiper stalk switch providing the following functions:
- Intermittent rear window wiping
- Programmed rear window wiping interval
- Operation of the rear window washer
Pressing the wiper stalk forward to the first detent activates the rear wiper in the intermittent mode.
The default timed interval is approximately 12 seconds. The full sweep and park positions are recognized by the two hail sensors on the motor gear assembly. If the wiper is switched OFF the wiper blade will return to the park position.
The programmed wiper interval procedure is identical to the E39 sport wagon; Briefly switch the rear wiper ON/OFF Wait the desired interval time, Switch the rear wiper ON again. The OFF time will be the programmed interval - up to approx. 30 seconds.
Rear window washing is activated by pressing the wiper stalk switch to the full forward position. The washer pump operates followed by two full wiping cycles. The wipers will then switch to the intermittent wiping mode.
When the transmission is shifted into reverse, the wiper will switch to continuous operation until the vehicle is shifted out of reverse. This high signal is provided by the LCM III when it activates the back up lights.