Instrument Cluster / Carrier: Description and Operation

Instrument Cluster Description and Operation

Displays Test

Certain instrument panel cluster (IPC) features are tested when the ignition is turned ON in order to verify that the features are working properly. The following indicators illuminate briefly at key up unless otherwise noted:

* ABS
* Air bag-flashes 7 times
* BRAKE
* Charge indicator-stays ON
* Coolant temp
* Cruise
* Fasten safety belt-flashes
* Low oil pressure indicator
* Malfunction indicator lamp (MIL)-stays ON
* Security
* Traction off

Indicators and Warning Messages

Refer to Indicator/Warning Message Description and Operation.

Clock

The radio sends current time to the instrument panel cluster (IPC) via class 2. The IPC receives a class 2 message from the radio indicating the time. The IPC analog clock, if equipped, zeroes itself to 12:00 during key up and then resets to the current time via the class 2 message received from the radio.

Engine Coolant Temperature Gage

The engine control module (ECM) sends the coolant temperature to the body control module (BCM) via class 2. The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the BCM. The IPC receives a class 2 message from the BCM indicating the engine coolant temperature. The engine coolant temperature (ECT) gage, if equipped, defaults to 75°C (160°F) or below if:

* The ECM detects a malfunction in the ECT sensor circuit.
* The IPC detects a loss of class 2 communications with the BCM.
* The BCM detects a loss of class 2 communications with the ECM.

Refer to Cooling System Description and Operation for more information.

Fuel Gage

The engine control module (ECM) sends fuel level percent to the instrument panel cluster (IPC) via class 2. The IPC displays the fuel level as determined by the ECM. The IPC receives a class 2 message from the ECM indicating the fuel level percent. The fuel gage defaults to E (empty) if:

* The ECM detects a malfunction in the fuel level sensor circuit.
* The IPC detects a loss of class 2 communications with the ECM.

When the fuel level is less than 4 percent, the low fuel indicator illuminates. For more information about the fuel system, refer to the following:

* Fuel System Description for the 2.8L engine
* Fuel System Description for the 3.6L (LY7) engine

Odometer

The instrument panel cluster (IPC) displays the vehicle mileage and trip mileage as determined by the engine control module (ECM). The IPC calculates the vehicle mileage based on the speed pulses from the vehicle speed sensor (VSS) signal and calculating the mileage for odometer displays. The odometer will display Error if an internal IPC memory failure is detected and DTC B1009 is set.

Speedometer

The instrument panel cluster (IPC) displays the vehicle speed based on the information from the engine control module (ECM). The ECM sends a 4,000 pulse per mile signal to the cluster discretely. The IPC calculates the vehicle speed using the time difference between consecutive pulses. The speedometer will default to zero if the time duration since the last speed pulse is greater than or equal to one second.

Tachometer

The instrument panel cluster (IPC) receives a discrete input from the engine control module (ECM) indicating vehicle speed. Each engine revolution is represents 2 input pulses to the ECM. The instantaneous engine speed is calculated by the ECM using the time difference between the 2 input pulses. The tachometer will default to 0 RPM if:

* The ignition is in OFF, ACCESSORY,or CRANK.
* The time duration since the last pulse is greater than or equal to one second.