Rear  Window  Wiper/Washer  System  (E39  Sport  Wagon  and  E53): The  system  is
included in the scope of ZKE however is not controlled directly by the GM. The control elec-
tronics are integrated into the rear wiper motor assembly. The control electronics 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  control  electronics  are  connected  to  the  vehicle
electrical system via a single seven pin connector.
The  rear  wiper  system  is  operator  controlled
through the wiper stalk switch providing the fol-
lowing 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 intermit-
tent mode
. The timed interval is approximately 7-12 seconds. The full sweep and park posi-
tions  are  recognized  by  the  two  hall  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 as follows:
• 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. Additionally, the system automatically controls the
following safety and convenience features:
• Wiper interrupt with the rear glass opened
• Wiping interrupt with a blocked wiper arm
• Continuous wiping when the vehicle is shifted into reverse 
When the transmission is shifted into reverse, the wiper will switch to continuous operation
until the vehicle is shifted out of reverse. This signal (high) is provided by the LCM III when
it activates the back up lights.
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Central Body Electronics ZKE III
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