Global Machinery Company Sierra 1999 - Manual (Page 158)

yellow blue
2-86
CHANGE ENGINE OIL
This message is displayed
when the engine oil needs
to be changed. The message
is only displayed for
15 seconds at the start
of each ignition cycle.
When you change the engine oil, be sure to reset the
Engine Oil Life Monitor. See “Engine Oil, When to
Change” in the Index.
SECURITY
This message is
displayed when the
content theft
- deterrent
system has been activated
and also monitors the
Passlock
R
System.
If the security message is displayed continuously while
driving and stays on, there may be a problem with the
Passlock System. Your vehicle will not be protected by
Passlock, and you should see your GM dealer.
SERVICE 4WD (If Equipped)
If the SERVICE 4WD
message comes on, there
may be a problem with the
Automatic Transfer Case
and service is required.
Malfunctions can be indicated by the system before any
problem is apparent, which may prevent serious damage
to the vehicle. This system is also designed to assist
your service technician in correctly diagnosing
a malfunction.