ZKE - 22
CENTRAL LOCKING BUTTON
The central lock button in the center console
provides a momentary ground input signal to the
GM.
• This input initiates a single lock for each door
and the trunk.
• The fuel filler flap remains unlocked for
refueling purposes.
• If a door is manually opened while centrally
locked, the remaining doors stay locked.
The opened door can be re-locked when closed by manually locking or pushing the central
button twice. This allows the locks of the remaining doors to be re-synchronized again.
As an additional safety feature, the central lock button input also unlocks a double locked
system. Pressing the button returns the system to central lock (single) position, allowing
the doors to be opened when the interior door handles are opened twice. This feature was
also added to other ZKE systems during the 1999 model year.
CRASH SIGNALLING
The Multiple Restraint System (MRS III) provides a switched signal to the GM in the event
of an accident. The signal is an output function of the MRS control module and becomes
active when MRS determines a crash has occurred.
When active, the GM unlocks the door lock actuators, switches on the interior lights and
signals the LCM III via the K bus to activate the hazard warning flashers.
Once the crash signal is active, the GM will not respond to lock requests from the system
until the ignition switch is cycled or a front door is opened.
