Principles of Operation: Notes

WARNING: This page is about a different car, the 2007 Lincoln MKX and 2007 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

The message center is an integral part of the instrument cluster that receives and acts upon much of the same information that is input and used to operate the instrument cluster gauges, indicators, and warning indicators. The message center, located in the center of the instrument cluster is a vacuum fluorescent 2-line display. The message center electronic functions use both hardwired, and the controller area network (CAN) circuitry to transmit and receive information.

Whenever conditions are present that require a warning message, the message center replaces the last selected display with the new warning display. Once the message is reset or cleared, the message center returns to the last selected display. If multiple warnings are present, the message center displays each warning for approximately 4 seconds. Warning messages are also generally associated with other observable instrument cluster indications. For example, when the LH front door is opened, the message center displays the message DRIVER DOOR AJAR along with the door ajar warning indicator. This allows the message center to be a more informative supplement to the instrument cluster gauges and indicators.

It is very important to understand:

where the input (command) originates.
all the information (messages) necessary in order for a feature to operate.
which module(s) receive(s) the input or command message.
if the module that received the input (message) controls the output of the feature, or if it outputs a message over the CAN to another module.
which module controls the output of the feature.