relay BMW 528I 2002 E39 Central Body Electronics ZKE Manual
Page 48 of 80
Sunroof Motor/Module (SHD): The motor is powered to open, close and lift the sunroof
panel. The motor contains two hall effect sensors that monitor the motor shaft rotation pro-
viding sunroof panel position.
The  hall  sensors  also  provide  the  end  limit  cut
out function for the SHD once the system is ini-
tialized.  The  SHD  counts  the  pulses  and  cuts
the  motor  out  prior  to  the  detected  end  run  of
the sunroof panel.
The  combined  motor  module  has  a  pin  con-
nector  for  interfacing  the  switch,  and  vehicle
harness (power, ground and Bus.) 
The  electronic  controls  and  relays  are  contained  in  the  sunroof  module  (PM-SHD).  The
module is connected to the P-Bus (E38 >99 MY on the K-Bus) for comfort closing/open-
ing and diagnosis/fault memory purposes.
48
Central Body Electronics ZKE III
System Components:   Inputs - Processing - Outputs
/K-BUS 
Page 50 of 80
Workshop Hints
SHD Self Diagnosis
The  SHD  monitors  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 the 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.
50
Central Body Electronics ZKE III 
Page 75 of 80
General Functions of ZKE III
Consumer Cut Off
The Consumer Cut Off function interrupts battery voltage to circuits preventing inadvertent
battery  drain  if  one  of  these  consumers  were  to  remain  activated.  Circuits  controlled  by
consumer cut off will be switched off as the GM enters into the sleep mode.
For example, the interior lights are connected to the consumer cut out circuit (KL 30) and
can  remain  on  if  one  of  the  control  switches  are  left  on.  The  consumer  cut  off  will  deacti-
vate KL 30 to the interior lighting after 16 minutes (or with the DISplus/MoDIC).
The  following  circuits  are  con-
trolled by consumer cut off:
• Map/Reading Lights
• Glove Box/Luggage Compart- 
ment Lights
• Transmission Range Indicator  
Light
• Overload Protection Relay for
- Power Seat Motors
- Steering Column Motors
Overload Protection
The seat and steering column motors receive
operating  power  through  the  consumer  cutoff/
overload protection relay module. The consumer
cutoff  signal  from  the  GM  signals  the  relay  to
maintain operating power to the consumers. 
If the relay module detects an increase in amper-
age (overload) the relay will open. The relay mod-
ule  (K-72)  is  located  in  the  electrical  carrier
behind  the  glove  box.  The  relay  is  reset  by
switching  the  ignition  “off”  for  16  minutes,  dis-
connecting the relay or the DISplus/ MoDIC. 
75
Central Body Electronics ZKE III
E38 Shown
Overload
Protection Relay
Module