Monitor Description

The transmission control ECU and the ECM communicate with each other using two-way communications via the Controller Area Network (CAN). The transmission control ECU sends signals concerning required engine RPM, required engine torques, warning indicators in the combination meter, DTCs, etc. The ECM sends signals concerning engine RPM, opening angles of the throttle valve, temperatures of intake air, temperatures of engine coolant, engine torques, etc. If the transmission control ECU cannot communicate with the ECM, the transmission control ECU will conclude that there is a malfunction of the CAN system, illuminate the MIL and set a DTC.