2005 Chevrolet TrailBlazer Owner's Manual - Page 346

Then, without shutting off the engine, follow these steps: Locate the handle with the transmission and lock symbols for the automatic transmission dipstick in the engine compartment on the passenger's side of the vehicle. See "Engine Compartment Overview" in the Index 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. 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. How to Add Fluid Refer to the Maintenance Schedule to determine what kind of transmission fluid to use. See "Recommended Fluids and Lubricants" in the Index. Add fluid only after checking the transmission fluid while it is hot. (A cold check is used only as a reference.) If the fluid level is low, add only enough of the proper fluid to bring the level up to the HOT area for a hot check. It doesn't take much fluid, generally less than one pint (0.5 L). Don't overfill. 6-20