2009 Mercury Grand Marquis Owner's Manual - Page 253

Maintenance and Specifications Low fluid level Do not drive the vehicle if the fluid level is at the bottom of the dipstick and the ambient temperature is above 50°F (10°C). Correct fluid level The transmission fluid should be checked at normal operating temperature 150°F-170°F (66°C-77°C) on a level surface. The normal operating temperature can be reached after approximately 20 miles (30 km) of driving. You can check the fluid without driving if the ambient temperature is above 50°F (10°C). However, if fluid is added at this time, an overfill condition could result when the vehicle reaches normal operating temperature. The transmission fluid should be in this range if at normal operating temperature (150°F-170°F [66°C-77°C]). The transmission fluid should be in this range if at ambient temperature (50°F-95°F [10°C-35°C]). High fluid level Fluid levels above the safe range may result in transmission failure. An overfill condition of transmission fluid may cause shift and/or engagement concerns and/or possible damage. High fluid levels can be caused by an overheating condition. 253 2009 Grand Marquis (grn) Owners Guide (own2002), 2nd Printing USA (fus)