Principles of Operation
NOTE:
A new instrument cluster must be reconfigured.
The instrument cluster (IC) is a hybrid electronic cluster (HEC). The instrument cluster uses both hard-wired and the standard corporate protocol (SCP) (J1850) line 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 (J1850) line network to another module?
- which module controls the output of the feature.
The instrument cluster carries out a display prove-out to verify that all warning/indicator miniature bulbs and monitored systems are functioning correctly. When the ignition switch is in the ON position with the engine off, the following warning indicators will illuminate:
- malfunction indicator lamp (MIL) (SERVICE ENGINE SOON)
- charging system indicator
- low oil pressure warning indicator
- anti-lock brake (ABS) warning indicator
- safety belt warning indicator
- air bag warning indicator
- BRAKE warning indicator
- low fuel indicator
- THEFT indicator
- low coolant warning indicator (3.0L engine)
- O/D OFF indicator