Principles of Operation

NOTE: A new instrument cluster must be reconfigured. Refer to Section.

The instrument cluster is a hybrid electronic cluster (HEC). The instrument cluster uses both hardwired and the standard corporate protocol (SCP) communication network to transmit and receive information. As a technician it is very important to understand:

• where the input originates from.
• all information necessary in order for a feature to operate.
• which module(s) receive(s) the input or command message.
• does the module which received the input control the output of the feature, or does it output a message over the SCP network to another module?
• which module controls the output of the feature.

The instrument cluster carries out a display prove-out to verify that the warning/indicator miniature bulbs for monitored systems are functioning correctly. When the ignition switch is in the ON position with the engine off, the following warning indicators will prove out:

• anti-lock brake (ABS) warning indicator
• air bag warning indicator
• BRAKE warning indicator
• charging system indicator
• fail safe cooling warning indicator
• low coolant level indicator
• low fuel warning indicator
• traction control indicator