F 250 4WD LD Pickup V8-5.4L SOHC VIN L (1997)
Overdrive Indicator Lamp: Description and Operation
The transmission control switch is a momentary contact switch. When the switch is pressed, a signal is sent to the Powertrain Control Module (PCM).
The powertrain control module then energizes the transmission control indicator lamp and the coast clutch solenoid, applying the coast clutch to provide
engine braking, and cancels fourth gear operation. The TCIL indicates overdrive cancel mode activated (lamp ON), electronic pressure control circuit
shorted or monitored sensor failure (lamp flashing).
