2006 GMC Yukon Owner's Manual - Page 398

Then, without shutting off the engine, follow these steps: The transmission dipstick handle with this graphic is located at the rear of the engine compartment, on the passenger's side of the vehicle. See Engine Compartment Overview on page 5-12 for more information on location. 1. Flip the handle up and then 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 both sides of the dipstick, and read the lower level. The fluid level must be in the COLD area, below the cross-hatched area, for a cold check or in the HOT or cross-hatched area for a hot check. Be sure to keep the dipstick pointed down to get an accurate reading. 4. If the fluid level is in the acceptable range, push the dipstick back in all the way; then flip the handle down to lock the dipstick in place. Consistency of Readings Always check the fluid level at least twice using the procedure described previously. Consistency (repeatable readings) is important to maintaining proper fluid level. If inconsistent readings persist, check the transmission breather hose to be sure it is clean and unclogged. If readings are still inconsistent, contact your dealer. 5-24