DTC U0129: Lost Communication With Brake System Control Module (P-CAN): General Description

The Controller Area Network (CAN) high speed bus is used where data needs to be exchanged between modules at a high rate, to minimize the delay between the occurrence of a change in sensor value and the reception of this information by a control device using the information to adjust 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 2.0(+/- 0.5)V.