2003 GMC Sierra 1500 Pickup Owner's Manual - Page 405

Hot Check Procedure The fluid must be hot to ensure an accurate check. The fluid level rises as temperature increases. 1. Operate the transmission in DRIVE (D) range until the normal operating temperature of 160°F (71"C) to 200°F (93°C) is reached. Consistency of Readings Always check the fluid level at least twice using the procedures described previously. Consistency (repeatable readings) is important to maintaining proper fluid level. If inconsistent readings persist, check the transmission breather to be sure it is clean and unclogged. If readings are still inconsistent, contact your dealer. 2. Pull out the dipstick and wipe it with a clean rag or paper towel. 3. Push it back in all the way, wait three seconds and then pull it back out again. Repeat the check procedure to verify the reading. 4. Safe operating level is within the HOT RUN band on the dipstick. The width of the HOT RUN band represents approximately 1.06 quart (1.O liter) of fluid at normal operating temperature. How to Add Fluid Refer to the Maintenance Schedule to determine what kind of transmission fluid to use. See Part D: Recommended Fluids and Lubricants on page 6-78. Add fluid only after checking the transmissionfluid 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 over%//. Notice: We recommend you use only fluid labeled DEXRON@111, because fluid with that label is made especially for your automatic transmission. Damage caused by fluid other than DEXRON@ 111 is not covered by your new vehicle warranty. After adding fluid, recheck the fluid level as described under How to Check. When the correct fluid level is obtained, push the dipstick back in all the way. 5. If the fluid level is not within the HOT RUN band, add or drain fluid as necessary to bring the fluid level to within the HOT RUN band. 6. If the fluid level is in the acceptable range, push the dipstick back in all the way. 5-30