Security Light; Service Four-Wheel Drive Warning Light - GMC YUKON DENALI 1999 Owner's Manual

Security Light

The light will stay on until the engine starts. If the light
R
flashes, the Passlock System has entered a tamper
mode. If the vehicle fails to start, see "Passlock" in
the Index.
If the light comes on 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.
2-80
This light will come on
briefly when you turn the
key to START.

Service Four-Wheel Drive Warning Light

Your vehicle is equipped with an Automatic
- -
Four Wheel Drive Transfer Case. It has a computer
-
which controls the four wheel
If the SERVICE 4WD light comes on, there may be a
problem with the Automatic Four
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.
-
drive system.
This light should come on
briefly when you turn on the
ignition, as a check to show
you it is working.
- -
Wheel Drive system
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