Principles of Operation

PRINCIPLES OF OPERATION

The message center electronic functions use both hardwired inputs and controller area network (CAN), and universal asynchronous receiver-transmitter (UART)-based protocol (UBP) communication networks to transmit and receive information. 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 which received the input (message) controls the output of the feature, or if it outputs a message over the CAN or UBP circuits to another module.
- which module controls the output of the feature.

The message center provides the following features:
- information displays
- setup displays
- warning messages
- system check messages

The message center information can be selected through a set of 3 switches:
- INFO
- SETUP
- RESET

Tire Pressure Monitoring System
The following messages can appear with a tire pressure monitoring system (TPMS):
- CHECK TIRE PRESSURE
- CHECK SPARE TIRE PRESSURE
- WARNING TIRE VERY LOW
- TIRE PRESSURE SYSTEM OFF
- TIRE PRESSURE SYSTEM FAULT
- TIRE PRESSURE SENSOR FAULT

General information on these messages may also be found in the Owner's Literature.

Information Displays
The information displays are non-timed modes. The selected mode remains on until the driver presses a message center switch to change the mode, or until it is overridden by another mode. The information display modes are:
- odometer
- trip odometer
- compass
- distance to empty
- average fuel economy

Setup Displays
The setup displays are timed modes and terminate after a finite interval. The setup display modes are:
- language
- English/metric units
- system check
- oil life status
- oil life in xx%
- charge system status
- oil pressure status
- engine temp status
- washer fluid level
- brake fluid level
- fuel level status
- distance to empty
- tire warning

Every 180 days or 8,000 km (5,000 miles) the oil life display in the message center SYSTEM CHECK will decrease gradually from 100% to 0%. At 5% oil life, the CHANGE OIL SOON warning indicator illuminates. At 0% oil life, the OIL CHANGE REQUIRED warning indicator illuminates. Oil life status is continually displayed in the SYSTEM CHECK portion of the message center and oil life warnings appear if the oil life is low.

Warning Messages
The warning messages are single cycle, non-resettable, and repetitive warning messages. The single cycle warning messages are:
- CHANGE OIL SOON
- OIL CHANGE REQUIRED
- LOW WASHER FLUID LEVEL
- LOW BRAKE FLUID LEVEL

The single cycle warning messages display once whenever the ignition switch is turned to the ON position or a fault occurs in a system and can be cleared by pressing the RESET button.

The repetitive warning messages are:
- CHECK CHARGING SYSTEM
- TRANSMISSION OVERHEATED
- CHECK TRANSMISSION
- LOW FUEL LEVEL
- LOW OIL PRESSURE
- CHECK ENGINE TEMPERATURE
- CHECK TIRE PRESSURE
- CHECK FUEL CAP

The repetitive warning messages are displayed at a fixed interval whenever the ignition switch is turned to the ON position or the ACC position. To remove a repetitive warning message, press the RESET button. The message reoccurs after 10 minutes until the warning condition is corrected.

The tire pressure warning is displayed whenever the tire pressure module receives a signal from a tire pressure sensor indicating that the tire pressure is out of range.

The non-resettable warning messages display whenever the ignition switch is turned to the ON position and a fault occurs in a system. The fault must be corrected to clear the non-resettable warning messages.

The non-resettable warning messages are:
- DOOR AJAR
- BACKUP AID