1996 Mercury Cougar Owner's Manual - Page 61
1996 Mercury Cougar Manual
Page 61 highlights
If the light stays on or comes on when the engine is running, have the electrical system checked as soon as possible. Overdrive Off Indicator This light tells you that the Transmission Control Switch (TCS) on the gearshift lever has been pushed. When the light is on, the transmission will not shift into overdrive. Depressing the button on the shifter will return the vehicle to "overdrive on" mode. The transmission will be in the "overdrive on" mode when the vehicle is started even if the O/D OFF mode was selected when the vehicle was last shut off. NOTE: If the light does not come on when the TCS is depressed or if the light flashes when you are driving, have your vehicle serviced at the first opportunity. If this condition persists, damage could occur to the transmission. 61