Control Module: Description and Operation

The EC-AT (Electronically Controlled Automatic Transaxle) control unit, located under the floor carpet and a protective panel on the passenger side, sends a transmission range position signal to the ECU. The transmission-mounted inhibitor switch first signals the EC-AT control unit as to gear position and the signal is relayed to the ECU. Because engine operating requirements vary according to which transmission range the vehicle is operating in, the EC-AT signal is utilized in a variety of ECU output calculations:

Fuel injection quantity
Idle speed control
Ignition timing
Purge control
A/C operation