
Windshield Wiping/Washing
Purpose of the System
The  windshield  wiping/washing  functions  are  controlled  by  the  GM  III  when  the  ignition  is
in  position  KL  R  or  KL15.  The  system  has  four  wiping  stages  and  four  interval  wiping
speeds. The wiper motor output control is through two relays (double relay >98 MY, except
E38) that are located in the Electonics box (E box).
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  automati-
cally activates the wipers when the stalk switch is in the intermittent position.
System Components
Wiper Stalk Switch Input:The wiping stage inputs are coded signals through a two wire
link with a combination of high/low inputs. The wiping stages include:
Single  (S): Momentarily  holding  the  wiper
switch  down  in  the  single  position  provides  a
momentary  ground  signal  to  activate  a  single
sweep in slow speed.
Slow (I) and Fast (II): The stage I and stage II
wiping  speeds  are  road  speed  dependent.
Stage I switches to intermittent when the vehi-
cle is stopped and stage II switches to stage I
when stopped. 
Windshield Washing: The wash request provides a switched ground input to the GM by
pulling the stalk rearward. The GM activates the windshield washer pump directly.
Intermittent  (Int): The  intermittent  wiping  time  inputs  are  provided  by  a  potentiometer
mounted  in  the  wiper  stalk  switch  (1  through  4).  The  intermittent  wiping  intervals  are  also
dependent on the road speed. As road speed increases, the wiping interval is shortened.
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Blocking Protection = Return
Contact Signal must be
present every 16 seconds
or motor will be deactivated >98 MY
1.49v-3.5v
Headlight  Washing  (if  equipped):When  the  headlights  are  on,  the  headlight  washer
pump is activated with the first activation of the windshield washer pump. It is only activat-
ed again after five succesive windshield washer cycles during the same ignition key on cycle
(rest  function).  The  GM  recognises  headlights  on  via  K-Bus  signalling.  The  GM  provides  a
ground on the headlight washer relay control circuit providing pump operation. The head-
light washer pump is located on the side of the washer fluid reservoir.
System Components:   Inputs - Processing - Outputs
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E53 Shown 

• If the ignition switch is turned off with the wiper switch in the intermittent position, the rain
sensor will only become active after the ignition is switched back on and one of the fol-
lowing occurs:
- The stalk switch is moved from the intermittent position and then back.
- The knurled wheel setting is adjusted.
- or the wash function is activated.
The reasoning behind this switching strategy is to have the driver make a conscious deci-
sion to activate the system themselves. 
Rain Sensor Control Module Adaptation
The rain sensor control module adapts to the optics system environment as follows:
Windshield Aging:As the vehicle ages the possibility of stone chipping in the rain sensors
monitoring area may occur which will cause a loss of light in the optics system.  
The control module adapts for loss of light based on the intensity of the detected infra red
light with a cleared windshield (wiper motor park signal). Therefore, the rain sensors func-
tion is not adversely affected due to windshield aging.
Dirty  Windows:The  rain  sensor  adaptation  reacts  less  sensitively  to  a  dirty  windshield
(dirt, road salt, wax residue) after a completed wipe cycle. A dirty windshield has a film on
it that diminishes the ability of the infra red to refract into present water droplets. This caus-
es a delay in the rain sensor detection capabilities which lengthens the time intervals on an
intermittent wipe.
Windshield Wiper System Failsafe Operation
The GM provides failsafe operation of the wiper system if faults are detected with any of the
following input signals:
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Function Faulted Input Detected Failsafe Function
Intermittent Wipe
Short or open circuit of
the knurled wheel signalDelay value for
setting 3 used.
Intermittent wipe
with Rain SensorFaulted Rain Sensor or 
K-Bus Signal corruptNormal Intermittent
wipe implemented
Wiper Motor not
Functional MovingPark contact feedback
signal takes longer than
16 secondsWiper motor control
deactivated for 3
minutes 

Workshop Hints
Windshield Wiper Blade Service
To access the wiper blades for cleaning or replacement,the following is required:
• With the ignition switched on (KL15), switch the wiper stalk to the “Intermittant” wipe 
mode.
• Switch the ignition off when the wiper arms are in the “upright” position.
CAUTION: Do not allow the wiper arm to spring back against the windshield, glass
breakage will occur!
Rain Sensor Equipped Vehicles
Make sure the wiper blades are in perfect condition. Only use window cleaner to clean the
windows. Dirty  windows  can  cause  the  Rain  Sensor  control  module  to  set  a  fault
due to the end limits of its adaptation abilities.  
Rear Window/Wiper
The  wiper  arm  and  driveshaft  are  connected  by
splines. 
Special  tool  #61  1  320  is  required  to  hold  the  drive
shaft  in  the  park  position  prior  to  installing  the  wiper
arm on to the drive shaft. 
Windshield Wiper System Diagnosis
The GM monitors the following circuits:
• Wiper Potentiometer        • Wiper Motor                           • Terminal 30 
• Double Relay                  • Windshield Washer Pump   
Note: The wiper/washer operation will be interrupted during engine cranking. The GM pro-
vides this “unload” feature to preserve the battery voltage for the starter motor. 
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Central Locking
Purpose of the System
The  Central  Locking  System  provides  locking/
unlocking  of  the  entire  vehicle  from  one  central
exterior  point.  From  the  driver’s  door  or  the
remote (key-less) entry, a lock/unlock request will
lock/unlock all exterior doors, luggage compart-
ment and the fuel filler flap.  
From inside, the vehicle can be locked/ unlocked using a cen-
tral  locking  button  located  in  the  center  console. Individual
doors can be unlocked manually by pulling twice on the inte-
rior door handle. 
From 2000 MY
- if the vehicle has been double locked, press
the central locking button and pull the interior door handle
twice (alarm will sound when the door opens).
Locking the vehicle from the central switch will “single lock” all
doors, luggage compartment and not lock the fuel filler flap.
The Central Locking System utilizes the GM III and Door Modules to carry out all of the lock-
ing/unlocking features: 
• Remote (key-less) entry is standard.
• When locked from the outside, the vehicle will double lock and arm the DWA System. The  
ignition must be switched off and the driver’s door must be opened and closed. 
• Selective  unlocking  from  the  outside  of  the  vehicle.  Unlocking  from  the  driver’s  door  or
remote transmitter will only unlock the driver’s door and disarm the DWA System. A sec-
ond request will unlock the remaining doors and luggage compartment. This feature can
be modified for individual users in Key Memory to open all doors from a single request. 
• A single central locking button is installed in the center console that will operate when all
of  the  doors  are  closed.  Locking  the  vehicle  from  the  central  switch  will  “single  lock”  all
doors,  luggage  compartment  and  not  lock  the  fuel  filler  flap.  When  unlocking,  a  single
request will unlock the driver’s door only. This feature can be modified for individual users
in Key Memory to open all doors and luggage compartment from a single request.
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• A  remote  luggage  compartment  button  is  installed  in  the  left  kick  panel  (center  console
in the E53) to open the luggage compartment from inside the vehicle.
• The EWS is interfaced for double lock monitoring and unlock function. With the presence  
of an accepted EWS key in the ignition, the vehicle will be unlocked and disarm DWA.    
• The automatic locking feature (> 99 MY) activates the door locks when a road speed 
signal of 5 MPH  and engine RPM is detected via the K-Bus. The factory default setting 
of this feature is off (can be encoded on for individual users with Key Memory function).
• In the event of an accident (ignition on), the GM will be signalled to unlock all doors.
Hardware Features:
• The external lock cylinders are located in the  
driver’s door and luggage compartment lid   
(E53/E39 Sport Wagon does not have a tail- 
gate lock cylinder).
• The driver’s door and luggage compartment   
incorporates an overrunning lock cylinder. The  
lock cylinder will free wheel or spin If any key  
other than the vehicle key or tool, such as a  
screw driver, is inserted into the cylinder. The 
lock cylinders can be manually locked/un- 
locked  by turning the key “past” lock/unlock.
• The door lock buttons are mechanically uncoupled from the  
lock actuators when locked. 
The door lock buttons “mechanically” lock the individual 
doors. This provides manual locking in the event of a central  
locking malfunction.
• Child safety locks (located in 
the rear doors) are  actuated 
by inserting a key in the slot on  
the door latch or by sliding a  
lever (dependent on model). 
The door can now only be  
opened from outside.
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Door
Button
Lock
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• The luggage compartment can be manually   
locked with a “Master Key” and leaving the  
lock cylinder in the horizontal position which 
prevents opening by any other method (sec- 
ured for valet).
The luggage compartment release button in-  
side the vehicle will also be ignored by the GM.
Prior to 2000 MY the vehicle could be locked/ 
unlocked using the luggage compartment lock 
cylinder. 
• The glove box has a lock cylinder to secure the  
contents by manual locking with a “Master 
Key”  and leaving the lock cylinder in the hori-
zontal position which prevents opening by any 
other method (secured for valet). 
• The E38 has a lever behind the glove box han
dle which permits locking the glove box with-  
out a key. Opening still requires a key.
The valet key is not mechanically capable of
entering either of these lock cylinders.  
• The Fuel Filler Flap mechanical release is found 
in the right side of the luggage compartment.  
The “pull tether” is behind the button as shown  
on the right. 
Note:  Continuous  operation  of  locking/unlocking  will  cause  a  timed  arrest  of  the
locking  system.  When  activated,  the  timed  arrest  lasts  for  2  minutes  (or  recycle
the ignition KL15). The “crash” signal will override the timed arrest and unlock the
vehicle.
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Workshop Hints
Remote  Key  Initialization: The  initialization  of  the  FZV  keys  is  required  to  establish  the
Lock/Unlock  signal  synchronization  with  the  GM.  The  initialization  procedure  provides  the
GM with a key identification number and a “rolling code” for each key. If the initialization is
not performed, the GM will not respond to the key signals.
Up  to  4  remote  keys  can  be  initialized.  They  must  be  initialized  at  the  same  time.  Key  ini-
tialization is only possible with the vehicle unlocked.
Procedure:
1. Close all doors and have all keys available.
2. Using  key  number  1,  turn  the  ignition  switch  to  KL
R, then switch off within 5 seconds and remove the
first key.
3. Within  30  seconds  of  turning  the  ignition  switch  to
“off” Press and holdbutton #2.
4. While holding button #2, press and release(“tap”)
button #1 three timeswithin 10 seconds.
5. Release  both  buttons.  The  LED  in  the  key  will  flash
momentarily  (except  2000  MY).  The  GM  will  imme-
diately  lock  and  unlock  the  doors  signaling  a  suc-
cessful initialization.
6. If  additional  keys  need  to  be  initialized  repeat  steps
3 - 5 within 30 seconds.
7. Switching the ignition to KL R completes the initiali-
zation.
NOTE: The key memory  function of the GM responds
to the key identification number of each key. If the keys
are not initialized in the same order prior to initialization,
the key memory functions activated by the keys will not
be  assigned  correctly. Always  initialize  the  keys  in
the same order. 
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