Principles Of Operation
Instrumentation and Warning Chimes
Principles of Operation
NOTE: Whenever a network message is suspected as missing or confirmed by a missing message DTC (U-code), it is important to look for other conditions that may also be present in the Instrument Cluster (IC) and throughout the vehicle. Once a DTC is set in the IC, it may be helpful to review the complete message list available in Module Communications Network Testing and Inspection 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.
The IC uses input messages from other modules to control the gauges, informational indicators, warning indicators and warning chimes 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 brake status message is missing for less than 5 seconds and the brake warning indicator was on, 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 IC 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 to the normal operation descriptions located before each individual pinpoint test for further description of the default action specific to each indicator or gauge. If the messaged input to the IC returns at any time, the normal function of the gauge or indicator resumes.
It is very important to understand:
- where the input originates.
- all the 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 communication network to another module.
- which module controls the output of the feature.
Instrument Cluster (IC)
The IC utilizes a microprocessor to control the gauge and indicator functions. Data is sent to the IC over the Medium Speed Controller Area Network (MS-CAN) and the High Speed Controller Area Network (HS-CAN) bus lines and through hardwired circuitry from individual components. The IC uses each input to output an action to the gauges or indicators.
IC Gateway Function
The IC acts as a gateway module by receiving information in one format and transmitting it to other modules using another format. For example, the IC receives the vehicle speed data from the PCM over the HS-CAN, converts the data into an MS-CAN message and sends (gateways) the message to other network modules such as the Restraints Control Module (RCM), the Audio Control Module (ACM), and the Generic Electronic Module (GEM). This enables network communication between modules that do not communicate using the same network (HS-CAN or MS-CAN).
IC Configuration
The IC 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 be set only through the Programmable Module Installation (PMI) procedure or by using As-Built data. Refer to Module Configuration Programming and Relearning.
IC Configuration Parameters
IC Prove-Out
The IC and other vehicle modules carry out a display prove-out to verify that all module controlled warning/indicator lamps and monitored systems are functioning correctly within the IC. When the ignition switch is cycled to the ON position with the engine off, the indicators illuminate to prove-out according the following table:
Warning Chimes
The IC uses inputs that are both hardwired to individual components and messages that are sent from the other modules over the HS-CAN or MS-CAN to control the warning chime functions.
Warning Chime Characteristics
Each warning chime has unique characteristics that help to identify and differentiate each warning chime. 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 IC prioritizes the chimes according to a preset hierarchy programmed into the IC software. Generally, when more than one chime request is received by the IC, the most important 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 basic chime categories as listed below:
- Repetitive
- Single tone
- Tick-tock
The following table provides a summary of the chime characteristics including the chime priority.
IC 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 IC monitors the air bag warning indicator status internally and provides an air bag indication status report to the Restraints Control Module (RCM). When a fault is present in the Supplemental Restraint System (SRS) with the RCM sending the IC an air bag warning indicator on request and a fault is detected in the air bag warning indicator, the RCM sends the IC a secondary request to sound the air bag warning chime.
The air bag secondary warning chime inputs are the:
- Ignition RUN status.
- Air bag warning indicator request communicated by the RCM to the IC over the HS-CAN.
- Air bag warning indicator chime request communicated by the RCM to the IC over the HS-CAN.
Autolock Acknowledge Chime
The autolock acknowledge chime provides an audible notification that the operator has entered the autolock programming function of the GEM. When the autolock programming feature has been initiated, the GEM provides a chime request to the IC over the MS-CAN communication bus.
The autolock acknowledge chime inputs are:
- Ignition RUN status.
- Autolock chime request communicated by the GEM to the IC over the MS-CAN.
Autolock Enable/Disable Chime
The autolock enable/disable chime provides an audible confirmation that the autolock function has been enabled or disabled. When the autolock function has been enabled, the GEM provides a chime request to the IC over the MS-CAN communication bus and the IC provides a dual tone chime confirming the autolocks are enabled. When the autolock function has been disabled, the GEM provides a chime request to the IC over the MS-CAN communication bus and the IC provides a single tone chime confirming the autolocks are disabled.
The autolock enable/disable chime inputs are:
- Ignition OFF, ACC or RUN status.
- Autolock chime request communicated by the GEM to the IC over the MS-CAN.
Belt-Minder(R)
The Belt-Minder(R) is configurable either through the scan tool or manually by using the Belt-Minder(R) deactivating/activating procedure. Refer to Module Configuration Programming and Relearning for a list of configurable parameters used with the scan tool. To configure without using a scan tool, refer to Belt-Minder(R) Deactivating/Activating Service and Repair.
NOTE: When deactivating/activating the Belt-Minder(R) using the manual procedure, both seating positions are deactivated/activated at the same time using only the driver safety belt.
The Belt-Minder(R) feature supplements the current safety belt warning function and is enabled after the current safety belt warning is complete. The Belt-Minder(R) reminds the driver that the driver or front passenger safety belt is unbuckled by intermittently sounding a chime and illuminating the safety belt warning lamp in the IC once the vehicle speed exceeds 10 km/h (6.2 mph), and remains active for approximately 4.5 minutes from the time it is started. While activated, the Belt-Minder(R) chime and indicator flash and chime simultaneously from on for 6 seconds to chime off for 9.5 seconds (the safety belt warning indicator remains illuminated), repeating for up to 5 minutes.
The Belt-Minder(R) warning chime inputs are the:
- Ignition RUN status.
- Safety belt warning indicator request communicated by the RCM to the IC over the HS-CAN.
- Belt-Minder(R) chime request communicated by the RCM to the IC over the HS-CAN.
Door Ajar Warning Chime
The door ajar warning chime warns that a door is open or not fully closed. The chime sounds when any door or the hood becomes ajar while the ignition switch is in the RUN position.
The door ajar warning chime stops sounding and resets when all the doors and the hood are closed, or the ignition lock cylinder is placed in the OFF/LOCK or ACC position.
The door ajar warning lamp/chime inputs are the:
- Ignition RUN status.
- Door ajar status communicated by the GEM to the IC over the MS-CAN.
GEM Service Mode Chime
The GEM service mode chime is used to provide confirmation or to alert a technician that the service mode has been entered/exited or to confirm that a tested input has been activated. The GEM provides a chime request to the IC over the MS-CAN.
The GEM service mode chime inputs are the:
- Ignition RUN status.
- GEM service mode status communicated by the GEM to the IC over the MS-CAN.
GEM Transmitter Identification Code (TIC) Programming Chime
The GEM Transmitter Identification Code (TIC) programming chime is used to provide confirmation that the RKE key transmitter programming mode has been entered. The GEM provides a chime request to the IC over the MS-CAN.
The GEM service mode chime inputs are the:
- Ignition OFF, ACC, RUN or START status.
- GEM RKE key transmitter TIC programming status communicated by the GEM to the IC over the MS-CAN.
Headlamps On Warning Chime
The headlamps on warning chime sounds if the driver door is ajar, the headlamp switch is in the PARKING LAMPS or HEADLAMPS position, and the ignition switch is in the OFF/LOCK position with the key removed.
The headlamps on warning chime stops sounding when any one of the above conditions are removed or the battery saver has expired.
The headlamps on warning chime inputs are the:
- Ignition OFF or ACC status.
- Headlamp switch input to the GEM.
- Door ajar input from the driver door ajar switch to the GEM.
- Headlamps on chime request communicated by the GEM to the IC over the MS-CAN.
Key-In-Ignition Warning Chime
The key-in-ignition warning chime warns that the key is still in the ignition lock cylinder when the driver door is ajar. The key-in-ignition warning chime sounds when the driver door is ajar, the key is in the ignition lock cylinder and in the OFF/LOCK or ACC position.
The key-in-ignition warning chime stops sounding when the driver door is closed, the key is removed from the ignition lock cylinder or the ignition switch is turned to the RUN position.
The key-in-ignition warning chime inputs are the:
- Ignition RUN status.
- Key-in-ignition switch input to the IC.
- Driver door ajar input from the driver door ajar switch to the GEM.
- Driver door ajar status message from the GEM to the IC over the MS-CAN.
Not In Park Warning Chime
The not in park warning chime warns that the transaxle is not in park (P) when the ignition is placed in the OFF or ACC position and the driver door is ajar.
The not in park warning chime inputs are the:
- Ignition OFF or ACC status.
- Transaxle PARK (P) position input to the IC.
- Driver door ajar input from the driver door ajar switch to the GEM.
- Driver door ajar status message from the GEM to the IC over the MS-CAN.
Safety Belt Warning Chime
The safety belt warning chime warns that the driver safety belt is not fastened. The safety belt warning chime sounds when the driver safety belt is not fastened, the ignition lock cylinder is turned from the OFF/LOCK or ACC to the RUN or START position.
The safety belt warning chime stops sounding when the safety belt is fastened, when the ignition switch is turned from the RUN or START position to the OFF/LOCK or ACC position, or when the chime has sounded for approximately 6 seconds.
The safety belt warning chime inputs are the:
- Ignition RUN status.
- Driver safety belt warning chime request communicated by the RCM to the IC over the HS-CAN.
Turn/Hazard On Tone
Since the turn/hazard flasher is an electronic function of the GEM, the on/off sound that used to be present with standard bi-metal flashers is no longer present. To provide an audible sound and indicate that the RH/LH TURN or HAZARD indicators are on, the IC provides a tick-tock tone along with the visual turn signal indicators.
The turn/hazard on tone inputs are the:
- Ignition OFF, ACC, RUN or START status.
- Left turn indicator signal from the GEM to the IC through the MS-CAN.
- Right turn indicator signal from the GEM to the IC through the MS-CAN.