When you're towing, you press that button to lock out (OFF) the overdrive gear. This gives you better response and more torque, and keeps you from damaging the transmission from the heat buildup under load from towing. Plus, can actually give you better gas mileage while towing since the engine is theoretically in its power band better and can more easily cope with the load. There's other ways to use it, but that's the main reason why they were included.
When you're not towing, keep the overdrive (ON). It lowers the RPM at which the engine cruises thereby saving gas and reducing wear on the engine.
Now, why they have this function in a car rather than just in trucks, and why they decided to use a separate button rather than just another detent on the shifter, I'll never know.
where is the emergency override button in 2001 ford expedition
A malfunction has been detected - get it checked out
Only if you want to shut off the overdrive feature , because overdrive is the normally allowed position
Check the fuse.
It means you turned it off, usually a little button on the end of the shifter.
Your overdrive on / off button is on the end of your gear selector lever ( P R N etc. )
Anytime you don't want the transmission to shift into overdrive * if you are towing something , or if you are driving in hilly country where the transmission is constantly shifting between drive and overdrive , you can use the button on the end of the gearshift lever on your 1998 Ford Expedition to shut off the overdrive ( the word OFF will light up on the end of your gearshift lever )
There may be a reason why a Ford Expedition's overdrive light is flashing. Check the manual to see if there is a reason. If not, take your Ford to a mechanic.
If your refering to the over drive button. It's located on the shifter handle.
if you have overdrive in that car it means that your about to go into overdrive
when overdrive button is flashing, it is an indicater that there is a problem with your transmission. it may be a simple problem or it could be a major problem. take it to a transmission shop before you need to be towed into shop
Pressing it will disable the overdrive.