2010 Hummer H3 Owner's Manual - Page 280

10-14 Vehicle Care How to Add Automatic Transmission Fluid Refer to the Maintenance Schedule to determine what kind of transmission fluid to use. See Recommended Fluids and Lubricants on page 11‑8. 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 does not take much fluid, generally less than one pint (0.5 L). Do not overfill. Then, without shutting off the engine: 1. Flip the handle up and then pull out the dipstick and wipe it with a clean rag or paper towel. 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. The automatic transmission dipstick handle with this symbol on it is located in the engine compartment on the passenger side of the vehicle. See Engine Compartment Overview on page 10‑6 for more information on location. 2. Push it back in all the way, wait three seconds, and pull it back out again.