System Operation

Message Center

System Operation

System Diagram





Network Message Chart

Module Network Input Messages - IPC (Instrument Panel Cluster)










Oil Change Minder

The message center provides an oil change minder to inform the driver that an oil change is required. The duration of the interval between oil changes is calculated in the PCM (Powertrain Control Module) and varies due to driving conditions. The PCM (Powertrain Control Module) stores the oil life data in NVRAM (Non-Volatile Random Access Memory). If the battery is dead, the PCM (Powertrain Control Module) is disconnected, reflashed or the KAM (Keep Alive Memory) is reset, the oil life settings remain in the PCM (Powertrain Control Module) and display the remaining oil life once the vehicle is restored to normal operation. The PCM (Powertrain Control Module) assumes a base mileage of 16,090 km (10,000 mi) or 1 year for normal driving. However, this number is adjusted down for conditions such as high engine temperature, high engine RPM (Revolutions Per Minute), use of flex fuel and possibly low oil level. The PCM (Powertrain Control Module) calculates and provides an engine service indication message to the BCM (Body Control Module). The BCM (Body Control Module) in turn provides the engine service indication message to the IPC (Instrument Panel Cluster).

REFER to Message Center Configuration .

Compass Display

The vehicle heading is displayed in the message center as a 1 or 2 character display that indicates the current direction of the vehicle (N, NE, E, SE, S, SW, W, or NW). The compass continuously re-calibrates due to changes in the earth's magnetic field and remains accurate during most driving conditions.

The compass signal originates with the compass module. Compass data is transmitted to the BCM (Body Control Module) through a LIN (Local Interconnect Network) line.

Outside Air Temperature Display

The AAT (Ambient Air Temperature) sensor is hardwired to the PCM (Powertrain Control Module) through separate input and return circuits. The PCM (Powertrain Control Module) provides a reference voltage to the ambient air temperature sensor and monitors the change in voltage resulting from changes in resistance as determined by outside air temperature. The PCM (Powertrain Control Module) filters the ambient air temperature input and sends the BCM (Body Control Module) the air ambient temperature filtered message. The BCM (Body Control Module) sends the air ambient temperature filtered message to the IPC (Instrument Panel Cluster).

The PCM (Powertrain Control Module) is programmed to update the messaged outside temperature data at different rates depending on several criteria to prevent false temperature displays due to a condition known as heat soaking. Heat soaking is where the outside air temperature is hotter in the location of the AAT (Ambient Air Temperature) sensor than the actual outside air temperature.

When the sensed outside temperature rises, the display updates slowly at varying rates based on vehicle speed. When the sensed outside temperature drops, the display updates more quickly basically following the drop experienced by the AAT (Ambient Air Temperature) sensor.

Cruise Control Message Center Indicator

The IPC (Instrument Panel Cluster) receives the cruise control status message from the BCM (Body Control Module). The BCM (Body Control Module) receives the cruise control status message from the PCM (Powertrain Control Module).

Shift To Park Message Display

REFER to Park Position Detect Switch .

The IPC (Instrument Panel Cluster) displays a shift to park message when the vehicle is turned off with the shifter out of the PARK (P) position on vehicles with IA (Intelligent Access). The IPC (Instrument Panel Cluster) monitors the park position detect switch input through the park detect signal, or input circuit. The IPC (Instrument Panel Cluster) provides the transmission park status to the BCM (Body Control Module). When the selector lever is out of the PARK (P) position, the park detect switch closes to ground and the IPC (Instrument Panel Cluster) detects the reference voltage pulled low. The IPC (Instrument Panel Cluster) sends a park status message to the BCM (Body Control Module), indicating that the selector lever is not in PARK (P). The IPC (Instrument Panel Cluster) monitors the ignition state and when the ignition is OFF with the selector lever out of PARK (P), the IPC (Instrument Panel Cluster) displays the shift to park message.

Upshift Message Center Indicator

The upshift indicator informs the driver of shift points that provide the highest fuel economy. The upshift indicator is controlled by the IPC (Instrument Panel Cluster) based upon an upshift indicator request sent from the PCM (Powertrain Control Module) through the BCM (Body Control Module).

Alarm System Displays

The IPC (Instrument Panel Cluster) provides displays that indicate a PATS (Passive Anti-Theft System) key read failure or PATS (Passive Anti-Theft System) failure. The IPC (Instrument Panel Cluster) receives the passive anti-theft system (PATS) indication message from the BCM (Body Control Module).

Brake System Displays

The IPC (Instrument Panel Cluster) provides brake system displays for low brake fluid level, parking brake applied and ABS (Anti-Lock Brake System) concerns that display along with the brake warning indicator operation.

When the parking brake is applied, the BCM (Body Control Module) sends the parking brake warning request message to the IPC (Instrument Panel Cluster) to illuminate the brake warning indicator and turn on the parking brake applied message in the message center.

When a low brake fluid level condition exists, the BCM (Body Control Module) sends the brake fluid level low message to the IPC (Instrument Panel Cluster) to illuminate the brake warning indicator and turn on the brake fluid level low message in the message center.

When an ABS (Anti-Lock Brake System) concern exists, the ABS (Anti-Lock Brake System) module sends the brake warning request message to the BCM (Body Control Module). The BCM (Body Control Module) in turn sends the brake warning request message to the IPC (Instrument Panel Cluster) to illuminate the ABS (Anti-Lock Brake System) warning indicator, brake warning indicator and to turn on the traction control off message in the message center.

Stability-Traction Control System Displays

The IPC (Instrument Panel Cluster) provides a stability-traction control system message center message to indicate that the traction control is disabled. When certain conditions exist such as wheel speed sensor failure, control valve failures, communication failures or low battery voltage in the ABS (Anti-Lock Brake System), the ABS (Anti-Lock Brake System) module sends the brake warning request message to the BCM (Body Control Module). The BCM (Body Control Module) in turn sends the brake warning request message to the IPC (Instrument Panel Cluster) to illuminate the ABS (Anti-Lock Brake System) warning indicator, brake warning indicator, stability/traction control indicator (sliding car icon), stability/traction control disabled (sliding car OFF icon) and turns on the traction control off message in the message center.

Charging System Displays

The IPC (Instrument Panel Cluster) provides message center displays indicating the status of the charging system. The IPC (Instrument Panel Cluster) receives the power system status message from the BCM (Body Control Module) to display the over-voltage and low battery voltage message center warnings.

Engine Over-Temperature Displays

The IPC (Instrument Panel Cluster) provides a message center display to indicate the engine is over-temperature. The IPC (Instrument Panel Cluster) receives the engine coolant temperature message from the BCM (Body Control Module) to move the temperature gauge to full hot and display the engine over-temperature message center warning. The BCM (Body Control Module) receives the engine coolant temperature message from the PCM (Powertrain Control Module).

Electronic Throttle Control (ETC) or Engine Malfunction Displays

The IPC (Instrument Panel Cluster) provides a message center display to indicate there is an engine concern. The IPC (Instrument Panel Cluster) receives the engine MIL (Malfunction Indicator Lamp) request message from the BCM (Body Control Module) to illuminate the MIL (Malfunction Indicator Lamp) and display the engine malfunction message center warning. The BCM (Body Control Module) receives the engine MIL (Malfunction Indicator Lamp) request message from the PCM (Powertrain Control Module).

Oil Service Displays

The IPC (Instrument Panel Cluster) provides a message center display to indicate an engine oil change is due. The IPC (Instrument Panel Cluster) receives the engine service indication message from the BCM (Body Control Module). The BCM (Body Control Module) receives the engine service indication message from the PCM (Powertrain Control Module) to display the engine oil change due message.

Electronic Power Assist Steering (EPAS) System Displays

The IPC (Instrument Panel Cluster) provides a message center display to indicate there is an EPAS (Electronic Power Assist Steering) system concern. The IPC (Instrument Panel Cluster) receives the EPAS (Electronic Power Assist Steering) display message from the BCM (Body Control Module) to display the steering malfunction message center warning. The BCM (Body Control Module) receives the EPAS (Electronic Power Assist Steering) display message from the EPAS (Electronic Power Assist Steering) module.

Hill Start Assist System Displays

The IPC (Instrument Panel Cluster) provides a message center display to indicate the status of the hill start assist system. The IPC (Instrument Panel Cluster) receives the hill start assist status message from the BCM (Body Control Module). The BCM (Body Control Module) receives the hill start assist status message from the ABS (Anti-Lock Brake System) module.

Intelligent Access (IA) System Displays

The IPC (Instrument Panel Cluster) provides message center displays to indicate the status of the IA (Intelligent Access) system. The BCM (Body Control Module) receives the passive key status message from the RFA (Remote Function Actuator) module. The BCM (Body Control Module) receives the transmission gear display actual message and the transmission message request (transmission not in park) from the TCM (Transmission Control Module). The IPC (Instrument Panel Cluster) receives the passive key status, key warning indication, transmission gear display actual and intelligent access indication messages from the BCM (Body Control Module).

Exterior Lighting Bulb Failure Displays

The IPC (Instrument Panel Cluster) provides message center displays to indicate the status of exterior lighting bulbs. The BCM (Body Control Module) monitors the status of the exterior lighting bulbs and sends a bulb failure message to the IPC (Instrument Panel Cluster).

Door Ajar Indication Displays

The IPC (Instrument Panel Cluster) provides message center displays to indicate the status of the doors, liftgate/luggage compartment lid and hood. The BCM (Body Control Module) monitors each of the ajar inputs and sends a door status message to the IPC (Instrument Panel Cluster) to display the specific ajar status.

Parking Aid System Displays

The IPC (Instrument Panel Cluster) provides message center displays indicating the status of the parking aid system. The IPC (Instrument Panel Cluster) receives the parking aid active message from the BCM (Body Control Module). The BCM (Body Control Module) receives the parking aid active message from the PAM (Parking Aid Module).

Restraints Indication Displays

The IPC (Instrument Panel Cluster) provides a display to indicate an internal air bag indication failure. If the IPC (Instrument Panel Cluster) detects a failure in the air bag warning indicator after receiving the air bag indicator request from the RCM (Restraints Control Module) through the BCM (Body Control Module), the message center displays the air bag malfunction warning message.

Tire Pressure Monitoring System (TPMS) Displays

The IPC (Instrument Panel Cluster) provides message center displays to indicate the TPMS (Tire Pressure Monitoring System) sensor training status or a malfunction in the TPMS (Tire Pressure Monitoring System). The IPC (Instrument Panel Cluster) receives the tire pressure indication message from the BCM (Body Control Module).

Transmission Malfunction Displays

The IPC (Instrument Panel Cluster) provides message center displays to indicate transmission malfunctions. The IPC (Instrument Panel Cluster) receives the transmission message request from the BCM (Body Control Module). The BCM (Body Control Module) receives the transmission message request from the TCM (Transmission Control Module).

MyKey Function Displays

The IPC (Instrument Panel Cluster) provides message center displays for the MyKey(R) feature.

Low Washer Fluid Level Displays

The IPC (Instrument Panel Cluster) displays a message indicating the washer fluid level is low. The low washer fluid level sensor is hardwired to the BCM (Body Control Module). The IPC (Instrument Panel Cluster) receives the washer fluid level low message from the BCM (Body Control Module).