F 150 4WD Pickup V8-5.4L CNG VIN M (2001)
Transmission Mode Indicator - A/T: Description and Operation
TRANSMISSION CONTROL INDICATOR LAMP
The Transmission Control Indicator Lamp (TCIL) is an output signal from the PCM that controls the lamp on/off function depending on the
engagement or disengagement of overdrive. Refer to Transmission Control Switch, PCM Inputs.