Chevrolet 2002 TrailBlazer Owner's Manual page 314

Secondary Latch System
The spare tire hoist assembly is equipped with a
secondary latch system. It's designed to stop the spare
tire from suddenly falling off your vehicle. For the
secondary latch to work, the spare tire must be stored
with the valve stem pointing up. See "Storing a Flat or
Spare Tire and Tools" in the Index for instructions on
storing the spare tire correctly.
CAUTION:
Before beginning this procedure, read all the
instructions. Failure to read and follow the
instructions could damage the hoist assembly
and you and others could get hurt. Read and
follow the instructions listed below.
5-22
To release the spare tire from the secondary latch
do the following:
2. If it is not visible, proceed to Step 6.
If visible, first try to tighten the cable by turning the
wheel wrench clockwise until you hear two clicks or
feel it skip twice. You cannot overtighten the cable.
3. Loosen the cable by turning the wheel wrench
counterclockwise three or four turns.
4. Repeat this procedure at least two times.
If the spare tire lowers to the ground, continue with
Step 2 of "Removing the Spare Tire and Tools"
earlier in this section.
5. Turn the wrench counterclockwise until
approximately 6 inches (15 cm) of cable is exposed.
1. Check under the
vehicle to see if the
cable is visible.