Instrument Cluster Messages
The instrument cluster uses input messages from other modules to control the gauges, informational indicators, warning indicators and message center displays over the communication networks. If a required message is missing or invalid for less than 5 seconds, the gauge or indicator that requires the message remains at the last commanded state based upon the last known good message. For example, if the message is missing the O/D off status for less than 5 seconds and the O/D off indicator was ON (O/D cancelled), the indicator remains in the ON state until the next good message is received. If the message remains missing or invalid for greater than 5 seconds, the instrument cluster sets a U-code DTC and the output becomes a default action for the indicator or gauge. Each indicator or gauge utilizes a different default strategy depending on the nature of the indication. Refer INSTRUMENT CLUSTER for further descriptions of the default action specific to each indicator or gauge. If the messaged input to the cluster returns at any time, the normal function of the gauge or indicator resumes.