Summit Wagon FWD L4-2350cc 2.4L SOHC (1995)
Information Bus: Description and Operation
Three communication lines are connected between the engine control module (ECM) and the transaxle control module (TCM) to send and receive the
engine and transaxle control signal.
If the transistor inside the ECM changes from OFF to ON by the command if the ECM, the terminal having a voltage of 5V applied to it from the TCM
is grounded in the ECM. This will change the terminal voltage of the TCM from HIGH to LOW. If the transistor inside the TCM changes from ON to
OFF, the 5V terminal in the ECM is released and the terminal voltage of the TCM changes from LOW to HIGH.
In this way, the terminal voltage of the TCM is controlled by the ON/OFF operation of the transistor inside the ECM in order to send a signal. On the
other hand, the TCM controls the terminal voltage of the ECM by the ON/OFF operation of the transistor inside the TCM in order to send a signal. In
this way, the engine and transaxle send control signals to each other.
