GMC 1996 Sonoma Owner's Manual page 107

If the Light Is On Steady
Have you recently changed brands of fuel?
You may be able
t o
correct the emission system
malfunction by considering the following:
Did you just put fuel into your vehicle'?
If
so,
reinstall the fuel cap, making sure to fully install
the cap. The diagnostic system can determine if the fuel
cap has been left off or improperly installed. This will
allow fuel to evaporate into the atmosphere. A few
driving trips should turn the light off.
Did you just drive through a deep puddle
0 . f
water'!
If so. your electrical system
may
be wet. The condition
w i l l usually be corrected when the electrical system
dries out.
A
few driving trips should turn the light off.
Are you low on fuel?
As your engine starts to run out of fuel. your engine may
not
run
a s
efficiently
a s
designed since small amounts of
air are s ~ ~ c k e d into the fuel line causing
a
misfire. The
system can detect this. Adding fuel should correct this
condition. Make sure
t o
install the fuel cap properly.
It
w i l l take a few driving trips to turn the light off.
I f so, be sure
to
fuel your vehicle with quality fuel (see
"Fuel" in the Index). Poor fuel quality will cause your
engine not to run
a s
efficiently
a s
designed. You may
notice this as stalling after start-up, stalling when you
put the vehicle into gear. misfiring, hesitation on
acceleration or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the light
t o turn
on.
I f you experience this condition, change the fuel brand
you L I S ~ . It will require
a t
least one full tank of the
proper fuel to turn the light off.
If none of the above steps have made the light turn off,
have your dealer or qualified service center check the
vehicle. Your dealer has the proper test equipment and
diagnostic tools to fix any mechanical or electrical
problems that may have developed.
2-59