Data exchange system — description

1. The described vehicles have a complex electrical system, which includes many devices - energy consumers and several separate electronic units.

2. The main function of the control system unit (RSM) is automatic control of the engine and transmission elements. This unit is also connected to other electronic units of the car through a data exchange system, due to which serial data is quickly exchanged. Multiple devices are controlled from the body control unit (HSR), which is connected to the PCM control system unit.

3. In addition to the PCM and BCM units, the data exchange system includes an SRS system unit, an electronic brake system control unit, and an instrument panel unit. The BCM unit is also connected to various subsystems of the body equipment.

4. The corresponding fault codes can be stored in the electronic memory of each control unit. If normal checks fail to determine the cause of the malfunction, check the appropriate electrical diagrams at the end of this chapter for the presence of a PCM or BCM in the circuit. If these blocks are included in the circuit under test, contact a proprietary station to read the fault codes using special diagnostic equipment.