Starter Motor Request (SMR) Circuit
WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2015 Lincoln Navigator, 2015 Lincoln MKZ, 2015 Lincoln MKX, 2015 Lincoln MKT, and 2015 Lincoln MKS. However, it is still accessible from the selected car via links, so may be relevant.
The SMR circuit provides the PCM with a signal from the ignition switch to the PCM. The input is pulled high when the ignition is in the START position and the transmission range (TR) sensor ignition lockout circuit allows the starter to engage.