Instrumentation, Message Center and Warning Chimes
Instrumentation, Message Center and Warning Chimes
Principles of Operation
The Instrument Panel Cluster (IPC) utilizes a microprocessor to control the gauge, indicator, message center and warning chime functions. Data is sent to the IPC (Instrument Panel Cluster) over the High Speed Controller Area Network (HS-CAN) and through hardwired circuitry from individual components. The IPC (Instrument Panel Cluster) uses each input to output an action to the gauges, indicators, message center or chime arbitrator.
When diagnosing an IPC (Instrument Panel Cluster) concern, it is very important to understand:
- where the input originates.
- all of the information necessary for a feature to operate.
- which module(s) receive(s) the input or command message.
- which module controls the output of the feature.
- whether the module that receives the input controls the output of the feature, or whether it outputs a message over the communication network to another module.
Instrument Panel Cluster (IPC)
IPC (Instrument Panel Cluster) Network Messages
The IPC (Instrument Panel Cluster) uses input messages from other modules to control the gauges, informational indicators, warning indicators and message center indicators over the HS-CAN (High Speed Controller Area Network). Messages that originate within or are sent to other modules on the Medium Speed Controller Area Network (MS-CAN) are sent to the Body Control Module (BCM) and converted to an HS-CAN (High Speed Controller Area Network) message. For additional information on the communication networks or the BCM (Body Control Module) gateway function, refer to Information Bus. 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 message received. For example, if the brake status message is missing for less than 5 seconds and the brake warning indicator was illuminated, the indicator remains in the ON state until the next message is received. If the message remains missing or invalid for greater than 5 seconds, the IPC (Instrument Panel Cluster) sets a network U-code DTC and the IPC (Instrument Panel Cluster) 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 to the normal operation descriptions located in the individual pinpoint test for further description of the default action specific to each indicator or gauge. If the missing messaged input to the cluster returns at any time, the normal function of the gauge or indicator resumes.
NOTE: Whenever a message is suspected as missing and confirmed by a missing message DTC, it is important to look for other symptoms that may also be present in the IPC (Instrument Panel Cluster) and throughout the vehicle. Once a DTC sets in the IPC (Instrument Panel Cluster), it may be helpful to review the complete message list available in Information Bus to see what other modules also rely on the same message and run the self-test for those modules. If the message is missing from other modules, the same DTC may also be set in those modules. Confirmation of missing messages common to multiple modules may indicate that the originating module is the source of the concern or the communication network may be experiencing some problems.
IPC (Instrument Panel Cluster) Configuration
The IPC (Instrument Panel Cluster) contains items that are configurable. Configurable items include customer preference items, which can also be set with a scan tool. The remaining configurable items can only be set by the Programmable Module Installation (PMI) procedure or by using As-Built data. Refer to Information Bus.
The configurable IPC (Instrument Panel Cluster) items are as follows:
IPC (Instrument Panel Cluster) Configuration Parameters
IPC (Instrument Panel Cluster) Prove-Out
The IPC (Instrument Panel Cluster) and other vehicle modules carry out a display prove-out to verify all module controlled warning/indicator lamps and monitored systems are functioning correctly within the IPC (Instrument Panel Cluster). When the ignition is cycled to ON with the engine off, the indicators illuminate to prove-out according to the following table:
Information And Message Center
The message center is an integral part of the IPC (Instrument Panel Cluster) that receives and acts upon much of the same information that is input and used to operate the IPC (Instrument Panel Cluster) gauges, indicators, warning indicators and message center indicators.
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 IPC (Instrument Panel 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 message center warning indicator. This allows the message center to be a more informative supplement to the IPC (Instrument Panel Cluster) gauges and indicators.
Another function of the message center is to display message center warning indicators. The message center often displays a warning message and the message center warning indicator at the same time. For example, if the PCM detects low engine oil pressure, the PCM sends a request to the IPC (Instrument Panel Cluster) to illuminate the low oil pressure message center indicator and to display LOW OIL PRESSURE in the message center. If multiple warnings are present requiring multiple message center warning indicator displays, the message center cycles or rotates through the displays in the same manner the message center cycles the text messages.
Warning Chimes
Each warning chime has unique characteristics. The warning chimes use volume, chime frequency, length of time the chime sounds and the number of chime tones to identify which chime is sounding. The IPC (Instrument Panel Cluster) prioritizes the chimes according to a preset hierarchy programmed into the IPC (Instrument Panel Cluster) software. When more than one chime request is received by the IPC (Instrument Panel Cluster), the highest priority chime sounds. If a lower priority chime is currently sounding, the higher priority request takes over and replaces the lower priority chime.
There are 3 different chimes as listed below:
- Repetitive
- Single tone
- Tick-tock
The following table provides a summary of the chimes:
IPC (Instrument Panel Cluster) Chime Characteristics
Air Bag Secondary Warning Chime
The air bag secondary warning chime warns that the air bag warning indicator light does not work correctly. The IPC (Instrument Panel Cluster) monitors the air bag warning indicator status internally and provides an air bag indication status report to the RCM (Restraints Control Module). When a fault is present in the Supplemental Restraint System (SRS) with the RCM (Restraints Control Module) sending the IPC (Instrument Panel Cluster) an air bag warning indicator on request and a fault is detected in the air bag warning indicator, the RCM (Restraints Control Module) sends the IPC (Instrument Panel Cluster) a secondary request to sound the air bag warning chime.
The air bag secondary warning chime inputs are:
- Ignition state
- Air bag warning indicator request communicated by the RCM (Restraints Control Module) to the IPC (Instrument Panel Cluster)
- Air bag warning indicator chime request communicated by the RCM (Restraints Control Module) to the IPC (Instrument Panel Cluster)
Message Center Warning Chime
The message center warning chime feature draws the driver's attention to the message center display to view each new warning message. The IPC (Instrument Panel Cluster) provides a single one second tone whenever a new warning message is displayed in the message center. If multiple warning messages are present, the IPC (Instrument Panel Cluster) sounds a chime for each of the warning messages that are present.
Perimeter Alarm Warning Chime
The perimeter alarm warning chime alerts the driver that the perimeter alarm is armed when the driver door is unlocked with a key. The warning chime is only functional when a key is used to unlock the driver door. If the key fob or keypad (if equipped) is used to unlock the door, the perimeter alarm is disarmed and the warning chime does not sound. The warning chime sounds for 12 seconds when the driver door is opened and turns off when the perimeter alarm is disarmed (either by using the key fob, keypad or turning the key on). After the 12 second warning chime duration, the warning chime stops sounding and the perimeter alarm activates, sounding the horn and flashing the turn signal lamps.
Turn/Hazard On Chime
The turn/hazard on chime provides an audible sound to indicate the RH/LH turn or hazard lamps are on. When the LH turn lamps, RH turn lamps or hazard lamps are on, the IPC (Instrument Panel Cluster) provides a tick-tock tone along with the visual turn signal indicators.
The turn/hazard on tone inputs are:
- Left and right turn indicator signal from the BCM (Body Control Module) to the IPC (Instrument Panel Cluster) through the HS-CAN (High Speed Controller Area Network)
- Hazard signal from the BCM (Body Control Module) to the IPC (Instrument Panel Cluster) through the HS-CAN (High Speed Controller Area Network)