DTC U1117-88: High Speed CAN2 Communication (EMS-DCT): General Description

The Controller Area Network (CAN) high speed bus is used where data needs to be exchanged between modules at a high rate. The high rate is used to minimize the delay between the occurrence of a change in a sensor value, and the reception of this information by the control device using the information to adjust the vehicle system performance. The CAN network consists of two twisted wires; one signal circuit is identified as CAN-high and the other signal circuit is identified as CAN-low. At each end of the data bus there is a 120Ω termination resistor between the CAN-high and CAN-low circuits. When the CAN-high signal circuit is driven higher, to about 3.5V, and the CAN-low circuit is driven lower, to about 1.5V, the differential voltage becomes approximately 2.0V (+/- 0.5).