Circuit Description

A/T control relay supplies battery voltage to each solenoid valve. Solenoid valve closes when energized (on), and opens when de-energized (off). The PCM energizes or de-energizes solenoid valve, based on inputs from sensors such as TP sensor, PNP switch, stoplight switch, VSS, input shaft speed sensor, output shaft speed sensor, transmission fluid temperature sensor, etc. The PCM provides the ground to energize the solenoid. The ground time is displayed in percent. As the solenoid is energized or de-energized, it influences hydraulic pressure in the transmission applying and releasing elements.