GMC 2008 Envoy Denali Owner's Manual page 318

Checking the Fluid Level
Prepare your vehicle as follows:
1. Park your vehicle on a level place. Keep the engine
running.
2. With the parking brake applied, place the shift lever
in PARK (P).
3. With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the
shift lever in PARK (P).
4. Let the engine run at idle for three minutes or more.
5-24
Then, without shutting off the engine, follow these steps:
1. Flip the handle up and then remove the dipstick
and wipe it with a clean rag or paper towel.
See Engine Compartment Overview on page 5-12
for more information on location.
2. Reinstall it back in all the way, wait three seconds
and then pull it back out again. If the dipstick does
not go down the tube easily, turn the blade and
try again until it is fully inserted in the tube.
The automatic
transmission dipstick
handle with this symbol on
it is located in the engine
compartment on the
passenger's side of the
vehicle.