Security Light; Service Four-Wheel Drive Warning Light - GMC 1999 Suburban 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.
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This light will come on
briefly when you turn the
key to START.

Service Four-Wheel Drive Warning Light

(If Equipped)
If your vehicle is equipped with the automatic
- -
four wheel drive transfer case, it has a computer which
- -
controls the four wheel drive system.
The SERVICE 4WD light comes on to indicate that
there may be a problem with the automatic
- -
four wheel drive system 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.
This light should come on
briefly when you turn on the
ignition, as a check to show
you it is working.
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