Controller Area Network (Can)

Previously, for different computers in the vehicle to share the same information, each signal required a different pin and wiring. However, with the introduction of a CAN system, only two lines are required to achieve the same function. The information is in digital format. This method does not use a integrated ECM.

Fig 1: Controller Area Network (CAN) - Communication Diagram

Courtesy of HYUNDAI MOTOR CO.

Input signals to TCM through ' CAN communication' 

• Engine RPM, TPS signal
• A/CON signal, Engine coolant temperature
• Quantity of intake airflow, Vehicle speed
• Shift holding signal (FTCS ON)

Output signals from TCM through ' CAN communication' 

• Request signal for torque reduction
• ATF temperature, TCM type, TCM error or not
• Damper clutch ON, OFF / Gear position