DTC U0109-00: Lost Communication With Fuel Pump Control Module: 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 3.5 V and the CAN-Low circuit is driven lower to about 1.5 V. The differential voltage becomes Approximately 2.0 (+/- 0.5) V.