GMC 1996 Sierra Owner's Manual page 370

Starter Switch Check
When you are doing this check, the vehicle could
move suddenly. If it does, you or others could be
injured. Follow the steps below.
1.
2.
3.
Before you start, be sure you have enough room
around the vehicle.
Firmly apply both the parking brake (see "Parking
Brake" in the Index if necessary) and the regular brake.
NOTE: Do not use the accelerator pedal, and be
ready to turn off the engine immediately if it starts.
On automatic transmission vehicles, try to start the
engine in each gear. The starter should work only in
PARK (P) or NEUTRAL (N). If the starter works in
any other position, your vehicle needs service.
On manual transmission vehicles, put the shift lever
in NEUTRAL (N), push.the clutch down halfway
and
try
to start the engine. The starter should work
only when the clutch is pushed down all the way to
the floor. If the starter works when the clutch isn't
pushed all the way down, your vehicle needs service.
Brake-Transmission Shift Interlock (BTSI)
Check (Automatic Transmission)
I
A
CAUTION:
When you are doing this check, the vehicle could
move suddenly. If it does, you or others could be
injured. Follow the steps below.
1 .
2.
3.
Before you start, be sure you have enough
room around the vehicle. It should be parked on
a level surface.
Firmly apply the parking brake (see "Parking Brake"
in the Index if necessary).
NOTE: Be ready to apply the regular brake
immediately if the vehicle begins to move.
With the engine off, turn the key to the RUN
position, but don't start the engine. Without applying
the regular brake, try
to
move the shift lever out of
PARK (P)
with
normal effort. If the shift lever moves
out of PARK (P), your vehicle's BTSI needs service.
7-44