Principles of Operation: Notes

The instrument cluster is a hybrid electronic cluster (HEC) that uses a microprocessor to control the gauge and indicator functions. Data is sent to the instrument cluster over the high speed controller area network (HS-CAN) bus lines and through hardwired circuitry to individual components such as the oil pressure switch, the parking brake switch and the anti-lock brake system (ABS) module. The instrument cluster acts as a gateway module by receiving information in one format and transmitting it to other modules using another format. For example, the instrument cluster receives the four wheel drive (4WD) data from the 4WD control module over the HS-CAN and sends the 4WD status to the ABS module through hardwired circuitry. This enables communication with modules that are not on the HS-CAN. When installing a new instrument cluster, it is necessary to upload the module configuration to the scan tool. Following installation of the instrument cluster, download the module configuration from the scan tool into the new instrument cluster. See PROGRAMMABLE MODULE INSTALLATION to carry out the programmable module installation (PMI). It is also necessary to carry out a parameter reset procedure whenever a new instrument cluster or powertrain control module (PCM) is installed. See ANTI-THEFT SECURITY ACCESS .