GMC 1995 Jimmy Owner's Manual page 120

Normal operating range shows your engine speed during normal driving
conditions. For example, when the needle points to 2, it means the engine is
running at 2,000 revolutions per minute (rpm). The tachometer needle will
vary all the time that the engine is running.
The red warning range tells you that your engine speed is reaching its upper
limits. Don't drive very long with the tachometer in the red warning range.
If you have a manual transmission, shift to a higher gear as soon as possible.
If you have an automatic transmission, lift your foot off of the accelerator
pedal. If you drive for very
long with the tachometer in the red danger
range, engine damage will result.
I
NOTICE:
Do not operate the engine with the tachometer in the red range,
or engine damage will occur.
The red danger range tells you that your engine speed is at its upper limits.
You should immediately shift to a higher gear, or lift your foot off of the
accelerator pedal. If you drive for very long with the tachometer in the red
danger range, engine damage will result.
Warning Lights and Indicators
This part describes the warning lights and gages that may be on your
vehicle. The pictures will help you locate them.
Warning lights and gages can signal that something is wrong before it
becomes serious enough to cause an expensive repair or replacement.
Paying attention to your warning lights and gages could also save you or
others from injury.
Warning lights come on when there may be or is a problem with one of your
vehicle's functions. As you will see in the details on the next few pages,
some warning lights come on briefly when you start the engine just to let
you know they're working. If
you
are familiar with this section, you should
not be alarmed when this happens.
Gages can indicate when there may be or is a problem with one of your
vehicle's functions. Often gages and warning lights work together to let you
know when there's a problem with your vehicle.
When one of the warning lights comes on and stays on when you are
driving, or when one of the gages shows there may be a problem, check the
section that tells you what to do about it. Please follow this manual's advice.
Waiting to do repairs can be costly - and even dangerous. So please get to
know your warning lights and gages. They're a big help.
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