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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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