Data exchange system — description (Chevrolet Trailblazer 1)

1. The vehicles described 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 (CSMU) is automatic control of the engine and transmission elements. This unit is also connected to other electronic units of the vehicle via a data exchange system, which enables rapid exchange of serial data. Many devices are controlled from the body equipment control unit (BECU), which is connected to the PCM control system unit.

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

4. The corresponding fault codes can be stored in the electronic memory of each control unit. If the cause of the malfunction cannot be determined during the normal checks, check the corresponding electrical circuit diagrams provided at the end of this chapter for the presence of the PCM or BCM units in the circuit. If these units are included in the circuit under examination, contact an authorized service station to read the malfunction codes using special diagnostic equipment.