Engine and Transaxle Total Control Signal

PURPOSE
To provide better transaxle shifting and limit traction loss during acceleration.

OPERATION
There are 3 communication lines providing torque reduction request and torque reduction execution (retared timing) signals. They connect the engine control module (ECM) with the transaxle control module (TCM). Two of these lines send 5 Volts from the ECM to the TCM. The other provides 5 Volts from the TCM to the ECM.

Communication between control units is accomplished by switching ground circuits of the 5V reference signal "ON" or "OFF" as determined by the proper control unit for driving conditions.