Transmission Position Sensor/Switch: Description and Operation

This signal is sent from A/T control module as a battery voltage signal only when A/T is in "R", "D", "2" or "L" range. Thus, ECM judges whether A/T is in one of the above ranges or otherwise (i.e. in "P", or "N" range) and uses it as one of the signals to control the fuel injector and ISC solenoid valve.