relay BMW X5 2002 E53 Central Body Electronics Workshop Manual

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POWER DISTRIBUTION
The X5 utilizes a single high amperage fused
power distribution center located to the left EHC
air reservoir beneath the cargo area floor.
The main fuse box is located inside the glove
box above a hinged panel. This places the
power distribution close to the main electronics
carrier behind the glove box.
The glove box mounted fuse box includes fuses
1 - 64.
Mounted on the top surface of the fuse panel are
the following relays:
FUEL PUMP
HORN
HEATED STEERING WHEEL
VISUAL ENTRY AID RELAY MODULE(OPTIONAL - REFER TO 1999 MODEL UPDATE)
NOT SHOWN IN THIS PHOTO
This view shown through passenger side airbag opening in dash panel.

RADIO
UNLOADER
RELAY
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An additional fuse panel is located
in an electrical carrier located at
the right rear of the cargo area.
The panel contains fuses 72 - 87.
The carrier also contains the
following relays
LOWER TAILGATE
ACTUATOR RELAY
REAR WINDOW
DEFROSTER
RELAY






  
 
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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.
• 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.
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WINDSHIELD WIPER
DOUBLE RELAY

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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 5.3 liter
washer fluid reservoir located in the engine
compartment.
GM III
HEADLIGHT WASHER
RELAY
HEADLIGHT
WASHER
PUMP
WINDSHIELD
WASHER
PUMP
TAILGATE
WASHER
PUMP

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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
function 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 causes a
delay in the rain sensor detection capabilities which lengthens the time intervals on an
intermittent wipe.
SERVICE NOTE FOR VEHICLES EQUIPPED WITH THE RAIN SENSOR:
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.
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:
WINDSHIELD WIPER SYSTEM DIAGNOSIS
The GM monitors the circuits of the wiper potentiometer, wiper motor, double relay, the
windshield washer pump and terminal 30.
FUNCTION FAULTED INPUT DETECTED FAILSAFE FUNCTION
Intermittent wipe Short or open circuit of Delay value for setting 3
the knurled wheel signal used.
Intermittent wipe Faulted Rain Sensor or K Bus Normal intermittent wipe
with Rain Sensor Signal corrupt implemented
Wiper motor not Park contact feedback signal Wiper motor control
functional moving takes longer than 16 seconds deactivated for 3 minutes

All door lock actuators and the fuel filler flap actuator are controlled directly by the GM via
four internal load relays. The drivers door lock actuator has a separate circuit for the
selective unlocking feature.
If this feature is disabled by key memory encoding, the driver’s door lock actuator selective
unlock circuit is activated simultaneously with the balance of the motors during unlock.
CONTROL DURING DOUBLE LOCK:
CONTROL DURING SINGLE LOCK:
SELECTIVE SINGLE LOCK
- CONTROL - SWITCHED POWER -
SINGLE LOCK CONTROL
- SWITCHED POWER -
GROUND
DOUBLE LOCK CONTROL
-SWITCHED POWER-
FUEL
FILLER
FLAP
LEFT
REAR
DOORRIGHT
REAR
DOORPASS.
DOORDRIVER’S
DOOR
SELECTIVE SINGLE UNLOCK
- SWITCHED GROUND -
SINGLE UNLOCK CONTROL
- SWITCHED GROUND -
UNLOCK CONTROL
- SWITCHED POWER -
DOUBLE LOCK CONTROL
-GROUND-
FUEL
FILLER
FLAP
LEFT
REAR
DOORRIGHT
REAR
DOORPASS.
DOORDRIVER’S
DOOR
SELECTIVE SINGLE LOCK
- CONTROL - SWITCHED POWER -
SINGLE LOCK CONTROL
- SWITCHED POWER -
GROUND
NOT ACTIVE
FUEL
FILLER
FLAP
LEFT
REAR
DOORRIGHT
REAR
DOORPASS.
DOORDRIVER’S
DOOR
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CONTROL DURING SINGLE UNLOCK:

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POWER WINDOWS
The power window operation on the E53 is similar to previous systems. Features of the
system include:
• Control of the front and rear door window motors is carried out directly by the GM.
• One-touch operation in both directions on all four windows.
• Cable type window regulator used for all windows.
• Anti-trap detection is provided by the pressure sensitive finger guard .
• Push/pull window switches
• The rear window switches located in the rear doors can be deactivated by the pressing
child lock out switch in the center console.
• Convenience closing/opening of the windows from the driver's lock cylinder or
convenience opening only from the FZV remote key (FZV operation can be owner
customized with the Car Memory Function).
• Window operation with the ignition switched off until a door is opened or 16 minutes has
elapsed after the key is switched off.
• Window load switching is through relays integral of the GM for rear windows and in the
respective door switchblock modules for the front windows. The current draw is
monitored for end limit position. The maximum run time for the window motors is limited
to 8 seconds. This allows the motors to be switched off if the end limit load sensing fails.

SUNROOF
The sunroof is mechanically similar to previous systems. All of the electronic controls and
relays are contained in the sunroof module (SHD). The module is connected to the K-Bus
for comfort closing/opening, unloader signalling during engine startup, diagnosis and fault
memory purposes
SUNROOF SWITCH
Mounted in the sunroof motor trim cover is the sunroof switch. Also similar to previous
systems, the switch provides coded ground signals for system operation.
The following switch signals are generated over three wires through coded combinations:
• Rest position
• Slide open request (press and hold switch - first
detent of open position)
• Automatic slide open request (press further to
second detent and release)
• Tilt open (press and hold)
• Slide close request (press and hold switch - first
detent of close direction)
• Automatic slide close request (press further to
second detent and release)
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K BUS

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SHD SELF DIAGNOSIS
The SHD monitors its operation and stores fault codes if a defect is determined: The SHD
monitors the following conditions:
• SHD motor relays:The relays are checked for sticking contacts (plausibility) and non
functional contacts.
• Hall effect position sensors:The SHD must detect a pulse frequency from the hall
effect sensor(s) during operation.
• Sunroof Switch: The SHD monitors the signal plausibility of the coded signaling from
the sunroof switch.
SUNROOF FAULT RESPONSE CHARACTERISTICS
If a fault occurs with any of these functions, the SHD responds as follows:
• Overrides the end run detection.
• Switches the motor off if the relay contacts stick for more than 500 ms.
• Switches the motor off if pulses are not received.
EMERGENCY OPERATION OF SUNROOF
If the sunroof motor does not respond to the switch signals, the hex key in the trunk lid tool
kit is used to manually turn the motor shaft drive as on previous systems

GENERAL FUNCTIONS OF ZKE III
CONSUMER CUT OFF
The interior lights are connected to the consumer cut out circuit. These consumers are con-
nected to KL 30 and can remain on if one of the control switches are left on. This would
prevent the ZKE from going into the sleep mode. However, the consumer cut off will switch
Kl 30, to the interior lighting, off after 16 minutes.
OVERLOAD PROTECTION
The seat and steering column motors are provided operating power through the consumer
cutoff / overload protection relay module as on the E38. The consumer cutoff signal from
the GM signals the relay to maintain operating power to the consumers.
If an overload condition exists, the relay module detects the increase in amperage and
opens the relay. The relay module is located in the electrical carrier forward of the glove
box.
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