Transmission Control Switch (TCS)
On automatic transmission equipped vehicles, the TCS provides an input signal to the PCM whenever the switch is pressed. For F-Super Duty, the tow/haul indicator illuminates when the TCS is cycled to engage and disengage the tow/haul strategy. For E-Series, the overdrive cancel indicator illuminates when the TCS is cycled to engage or disengage the overdrive function of the transmission. For additional information and diagnostics, refer to the AUTOMATIC TRANSAXLE/TRANSMISSION .