Principles of Operation: Notes

WARNING: This page is about a different car, the 2009 Ford RV Cutaway, 2009 Ford Econoline, 2009 Ford E450 Super Duty, and 2009 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

All vehicles are equipped with a One-Touch Integrated Start (OTIS) starting system.

The starting system is electronically controlled by the PCM. The PCM receives the following inputs:

Correctly coded ignition key, from the Passive Anti-Theft System (PATS)
Starter motor request, ignition switch in the START position
Transmission in PARK or NEUTRAL, from the digital Transmission Range (TR) sensor

When the ignition switch is placed in the START position, voltage is supplied to the coil of the starter relay through the OTIS start diode. A starter motor request signal is also sent to the PCM. If the PCM recognizes the needed input signals, it provides the starter relay coil with both voltage and a ground. The starter relay contacts close providing voltage to the starter solenoid, allowing the starter motor to activate. Once the starter motor begins to crank, the ignition switch may be released. The starter motor will continue to crank until the engine starts, the timing circuit in the PCM times out or the ignition switch is turned to the OFF position.