GMC 1996 Sonoma Owner's Manual page 106

If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:
NOTICE:
If you keep driving your vehicle with this light
on, after a while, your emission controls may not
work as well, your fuel economy may not be as
good and your engine may not run as smoothly.
This could lead to costly repairs that may not be
covered by your warranty.
This light should come on, as a check
t o
show you
it
is
working. when the ignition is on and the engine is not
running. I f the light doesn't co~ne on, have
it
repaired.
This light will a l s o come on during a malfunction
in
one
of two ways:
0
Light Flashing --
A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service is required.
0
Light On Steady
--
A n emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis and
service may
be
required.
0
Reduce vehicle speed.
0
Avoid hard accelerations.
Avoid steep uphill grades.
If towing
a
trailer, reduce the amount of cargo being
hauled as soon as it is possible.
If the light stops flashing and remains on steady, see "If
the Light Is On Steady" following.
If the light continues to flash, when
it
is safe
t o
do so,
s ~ o p f l w \vhic*le. Put your vehicle in PARK (P). Turn the
key off. wait at least 10 seconds and restart the engine.
If the light remains on steady, see "If
the
Light Is On
Steady" following. If the light is
still
flashing follow the
previous steps, and drive the vehicle
t o
your dealer or
qualified service center for service.
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