GMC 2006 Sierra - Manual (Page 443)

Notice: Too much or too little fluid can damage your
transmission. Too much can mean that some of the
fluid could come out and fall on hot engine part or
exhaust system parts, starting a fire. Too little fluid
could cause the transmission to overheat. Be sure to
get an accurate reading if you check your
transmission fluid.
Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:
• When outside temperatures are above 90°F (32°C).
• At high speed for quite a while.
• In heavy traffic — especially in hot weather.
• While pulling a trailer.
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, run the engine for
at least once minute and shift to DRIVE (D). Then
shift to NEUTRAL (N) and then REVERSE (R) to fill
the hydraulic system. Then, position the shift lever in
PARK (P).
4. Allow the engine to run at idle (500–800 rpm).
Slowly release the brake pedal.
Then, without shutting off the engine, follow these steps:
Cold Check Procedure
The purpose of the cold check is to determine if the
transmission has enough fluid to be operated safely until
a hot check can be made. The fluid level rises as fluid
temperature increases. Do not fill above the COLD
CHECK band if the transmission fluid is below normal
operating temperatures.
1. Pull out the dipstick and wipe it with a clean rag or
paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.
3. Check the fluid level reading. Repeat the check
procedure to verify the reading.
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