GMC 1995 Jimmy Owner's Manual page 171

Try to drive straight up the hill if at all possible. If the path twists and
turns, you might want to find another route.
Ease up on your speed as you approach the top of the hill.
Attach a flag to the vehicle to make you more visible to approaching
traffic on trails or hills.
Sound the horn as you approach the top of the hill to let opposing
traffic know you're there.
Use your headlights even during the day. They make you more visible
to oncoming traffic.
Q:
What should I do if my vehicle stalls, or is about to stall, and I
A:
If this happens, there are some things you should do, and there are
some things you must not do. First, here's what you should do:
can't make it up the hill?
Push the brake pedal to stop the vehicle and keep it from rolling
backwards. Also, apply the parking brake.
If your engine is still running, shift the transmission into reverse,
release the parking brake, and slowly back down the hill in reverse.
If your engine has stopped running, you'll need
to restart it. With the
brake pedal depressed and the parking brake still applied, shift the
transmission to PARK (P) (or, shift to NEUTRAL (N) if your vehicle
has a manual transmission) and restart the engine. Then, shift to
reverse, release the parking brake, and slowly back down the hill as
straight as possible in reverse.
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