GMC 1995 Safari Owner's Manual page 107

If the light stays on, or comes on when you're driving, your vehicle needs
service. If the regular brake system warning light isn't on, you still have
brakes, but you don't have anti-lock brakes.
If
the regular brake system
warning light is also on, you don't have anti-lock brakes and there's a
problem with your regular brakes. See "Brake System Warning Light"
earlier in this part.
Malfunction Indicator Lamp
(S€l?VlC€ ENGINE SOON)
SERVICE
ENGINE
SOON
The amber
Malfunction Indicator
(SERVICE ENGINE
SOON) Lamp is
located on the
passenger side of your
standard cluster.
If
you have the digital
cluster, it is on the
driver's side.
A computer monitors operation of your fuel, ignition and emission control
systems. This light should come on when the ignition is on, but the engine is
not running, as a check to show you it is working. If it does not come on at
all, have it fixed right away. If it stays on, or it comes on while you are
driving, the computer is indicating that you have a problem. You should
take your vehicle in for service soon.
NOTICE:
If you keep driving your vehicle with this light on, after a while
the emission controls won't work as well, your fuel economy
won't be as good and your engine may not run as smoothly. This
could lead to costly repairs not covered by your warranty.
Indicator Lights
Indicator lights go on when you use your turn signals, change from low
beam headlamps to high beams, or when you use your hazard flashers. The
next few pages will also tell you about the indicator lights on your vehicle
and help you locate them.
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