Control Module: Description and Operation

4AT Control Unit:

PURPOSE
Control unit for various electrically operated functions of the NA4A-HL automatic transmission.

LOCATION
Behind left side kick panel.

OPERATION
To coordinate engine operating conditions with transmission functioning, the ECU informs the 4 A/T control unit of engine throttle position (throttle sensor). The control unit in turn uses this information in its calculations for functions such as gear selection, kickdown and torque converter lockup.