Circuit Operation

A/T control relay (terminal 4) receives the battery positive voltage through a dedicated 20 amp fuse.
When the ignition switch is turned to the "ON" position, the PCM (terminal 50) receives battery voltage from the ignition switch. The PCM (terminal 50) applies voltage to energize the A/T control relay (terminal 3). With the A/T control relay energized, system voltage is applied to the PCM (terminals 77 and 89).