Part 2

OPERATION

DOOR AJAR INDICATOR

The ajar indicators give an indication to the vehicle operator that one or more of the passenger compartment doors, the hood, the liftgate or the liftgate flip-up glass may be open or not completely latched. These indicators are controlled by the IC logic circuit based upon programming and hard-wired inputs received by the cluster from the door, liftgate and liftgate flip-up glass ajar switches as well as from electronic hood ajar switch status messages received over the CAN data bus from the BCM.

The ajar indicator function of the LCD unit is completely controlled by the IC logic circuit, and that logic will only allow this indicator to operate when the IC receives a battery current input on the fused B(+) circuit. Therefore, the LCD ajar indications can occur regardless of the ignition switch position. The IC will turn ON an ajar indicator for the following reasons:

- Ajar Switch Input or Status Message - Each time the cluster receives a door, liftgate or liftgate flip-up glass ajar switch input indicating that a door, the liftgate or the liftgate flip-up glass or any combination of these is open or not completely latched with the ignition switch in any position, the appropriate ajar textual message and icons will be illuminated. A hood ajar indication happens only with the ignition switch in the ON or START positions. If the cluster detects a vehicle speed input greater than zero (kilometers or miles-per-hour) while the ignition switch is in the ON or START positions, the ajar indication will be accompanied by a single chime tone. When the ignition switch is in any position except ON or START, any and all ajar indications will time out after about five minutes.

The IC continually monitors the door, liftgate and liftgate flip-up glass ajar switches to determine the status of the doors, liftgate and liftgate flip-up glass. The BCM continually monitors the status of the hood ajar switch, then sends the proper electronic hood ajar switch status message to the IC.

For proper diagnosis of the door, hood, liftgate and liftgate flip-up glass ajar switches and circuits, the BCM, the IC, the CAN data bus or the electronic communication related to ajar indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

ELECTRONIC THROTTLE CONTROL INDICATOR

The Electronic Throttle Control (ETC) indicator gives an indication to the vehicle operator when the ETC system, or a circuit or component of the system is ineffective. The ETC indicator is controlled by a transistor on the IC circuit board based upon programming and electronic messages received by the cluster from the PCM over the CAN data bus. The IC will illuminate the ETC indicator for about fifteen seconds each time the ignition is turned to the ON position, during the bulb test.

The ETC indicator LED is completely controlled by the IC logic circuit, and that logic will only allow this indicator to operate when the IC receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED will always be OFF when the ignition switch is in any position except ON or START. The LED only illuminates when it is provided a path to ground by the IC transistor. The IC will turn ON the ETC indicator for the following reasons:

- ETC Indicator Lamp-On Message - Each time the cluster receives an electronic ETC indicator lamp-ON message from the PCM, the ETC indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the PCM message. The indicator remains illuminated solid or continues to flash for about 12 seconds or until the cluster receives a lamp-OFF message from the PCM, whichever is longer. If the indicator is illuminated solid with the engine running the vehicle will usually remain drivable. If the indicator is flashing with the engine running the vehicle may require towing. A flashing indicator means the ETC system requires immediate service. The indicator will be extinguished when the ignition switch is turned to the OFF position.

The PCM continually monitors the ETC system circuits and sensors to decide whether the system is in good operating condition. The PCM then sends the proper lamp-ON or lamp-OFF message to the IC. If the PCM sends a lamp-ON message after the bulb test, it indicates that the PCM has detected an ETC system malfunction or that the ETC system is ineffective. The PCM will store a DTC for any malfunction it detects. Each time the ETC indicator fails to illuminate due to an open or short in the cluster ETC indicator circuit, the cluster sends a message notifying the PCM of the condition, then the IC and the PCM will each store a DTC.

For proper diagnosis of the ETC system, the PCM, the IC, the CAN data bus or the electronic communication related to ETC indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

ENGINE TEMPERATURE INDICATOR

The engine temperature indicator gives an indication to the vehicle operator when the engine temperature gauge reading reflects a condition requiring immediate attention. This indicator is controlled by a transistor on the IC circuit board based upon programming and electronic messages received from the PCM over the CAN data bus. The IC will illuminate the engine temperature indicator for about three seconds each time the ignition is turned to the ON position, during the bulb test.

The engine temperature indicator LED is completely controlled by the IC logic circuit, and that logic will only allow this indicator to operate when the IC receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED will always be off when the ignition switch is in any position except ON or START. The LED only illuminates when it is provided a path to ground by the IC transistor. The engine temperature indicator will also be turned on for the following reasons:

- Engine Temperature High Message - Each time the IC receives a message from the PCM indicating the engine coolant temperature is above about 252° F (122° C), the engine temperature indicator will be illuminated and a single chime tone is sounded. The indicator remains illuminated until a message from the PCM indicating that the engine coolant temperature is below about 246° F (119° C) is received, or until the ignition switch is turned to the OFF position, whichever occurs first. The chime tone feature will only repeat during the same ignition cycle if the engine temperature indicator is cycled off and then on again by the appropriate engine temperature messages from the PCM.

The PCM continually monitors the engine coolant temperature sensor to determine the engine operating temperature. The PCM then sends the proper engine coolant temperature messages to the IC. If the IC turns on the engine temperature indicator due to a high engine temperature gauge reading, it may indicate that the engine or the engine cooling system requires service.

ESC INDICATOR

The Electronic Stability Control (ESC) indicator gives an indication to the vehicle operator when the ESC has been activated. This indicator is controlled by a transistor on the IC circuit board based upon programming and electronic messages received by the cluster from the CAB and the Final Drive Control Module (FDCM) over the CAN data bus. The IC will illuminate the ESC/BAS indicator for about four seconds each time the ignition is turned to the ON position, during the bulb test.

The ESC indicator LED is completely controlled by the IC logic circuit, and that logic will only allow this indicator to operate when the IC receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED will always be OFF when the ignition switch is in any position except ON or START. The LED only illuminates when it is provided a path to ground by the IC transistor. The IC will turn ON the ESC/BAS indicator for the following reasons:

- ESC Indicator Lamp-On Message - Each time the cluster receives an electronic ESC/ indicator lamp-ON message from the CAB indicating that the ESC system has been activated, the ESC indicator will be illuminated. The indicator remains illuminated until the cluster receives a lamp-OFF message from the CAB, or until the ignition switch is turned to the OFF position, whichever occurs first.
- ESC Off Textual Message - Each time the cluster receives an electronic ESC OFF indicator lamp-ON message from the CAB indicating that the ESC system has been manually disabled, an ESC OFF textual message will appear within the cluster re-configurable dot matrix display. The ESC OFF textual message remains displayed until the cluster receives a lamp-OFF message from the CAB, or until the ignition switch is turned to the OFF position, whichever occurs first.
- ESC Textual Warning Message - When the CAB or FDCM detects certain monitored fault conditions, it will send electronic messages requesting the cluster display a textual warning message. Each time the cluster receives an electronic ESC textual warning request message from the CAB or FDCM, a WARNING! LIMIT SPEED textual message will appear within the cluster re-configurable dot matrix display to accompany an ESC indicator that is illuminated solid. This message indicates that the CAB or FDCM has detected a problem in one of the ESC system circuits or components.

The CAB and FDCM continually monitors the ESC circuits and sensors to decide whether the system is in good operating condition and the proper outputs to the components of the system. The CAB or FDCM then sends the proper lamp-ON or lamp-OFF message to the IC.

For proper diagnosis of the ESC/BAS system, the CAB, the FDCM, the IC, the CAN data bus or the electronic communication related to the ESC/BAS indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

FOG LAMP INDICATOR

The front fog lamp indicator gives an indication to the vehicle operator whenever the front fog lamps are illuminated. This indicator is controlled by a transistor on the IC circuit board based upon programming and electronic messages received by the IC from the BCM over the CAN data bus.

The front fog lamp indicator LED is completely controlled by the IC logic circuit, and that logic will allow this indicator to operate whenever the IC receives a battery current input on the fused B(+) circuit. Therefore, the LED can be illuminated regardless of the ignition switch position. The LED only illuminates when it is provided a path to ground by the IC transistor. The IC will turn ON the front fog lamp indicator for the following reasons:

- Front Fog Indicator Lamp-On Message - Each time the cluster receives an electronic front fog indicator lamp-ON message from the BCM indicating the front fog lamps are turned ON, the front fog lamp indicator will be illuminated. The indicator remains illuminated until the cluster receives a lamp-OFF message from the BCM, or until the exterior lamp load shedding (battery saver) timed interval expires, whichever occurs first.

The BCM continually monitors electronic exterior lighting switch request messages from the IC to determine the appropriate outputs to the front fog lamp relay. The BCM activates or deactivates the front fog lamp relay then sends the proper lamp-ON or lamp-OFF message back to the IC.

For proper diagnosis of the front fog lamp system, the BCM, the IC, the CAN data bus or the electronic communication related to front fog lamp indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

FUEL SAVER INDICATOR - ECONOMIZER (ECO / ECO-ON)

The ECO message will display below the outside temperature in the EVIC display. The message will appear whenever the vehicle is driven in a fuel efficient manner, if the feature is turned ON using the customer programmable feature within the EVIC display menu.

On base model vehicle, an ECO or ECO-on message will be displayed within the odometer display when selected by the vehicle operator. The fuel saver feature can be selected by pressing the odometer push-button and toggling through the menu.

This feature allows the vehicle operator to monitor when they are driving in a fuel efficient manner, and it can be used to modify driving habits in order to increase fuel economy.

GAS CAP INDICATOR

The gas cap indicator gives an indication to the vehicle operator when there is a gross leak detected in the on-board fuel vapor recovery system. This indicator is controlled by the IC logic circuit based upon programming and electronic messages received over the CAN data bus from the PCM.

The gas cap indicator function of the LCD unit is completely controlled by the IC logic circuit, and that logic will only allow this indicator to operate when the IC receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LCD gas cap indication will always be OFF when the ignition switch is in any position except ON or START. The IC will turn ON the gas cap indicator for the following reasons:

- Gas Cap Indicator Lamp-On Message - Each time the cluster receives an electronic gas cap indicator lamp-ON message from the PCM indicating there is a gross leak in the vapor recovery system, the gas cap indicator will be displayed. The indicator remains displayed until the cluster receives a lamp-OFF message from the PCM, until the cluster arbitrator logic determines that another display request has priority, or until the ignition switch is turned to the OFF position, whichever occurs first.
NOTE: If the vehicles On-Board Diagnostic (OBD) system determines that the fuel filler cap is loose, improperly installed, or damaged; a gas cap " ICON" will be displayed in the LCD. In this instance, verify the gas cap is properly installed and tightened.

The PCM continually monitors the on board vapor recovery system to determine whether there are air leaks in the system. The PCM then sends the proper lamp-ON or lamp-OFF message to the IC. If the IC turns ON the gas cap indicator due to a monitored gross leak in the vapor recovery system, it may indicate that the gas cap has been removed or is improperly installed.

For proper diagnosis of the on board vapor recovery system, the PCM, the IC, the CAN data bus or the electronic communication related to gas cap indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

HIGH BEAM INDICATOR

The high beam indicator gives an indication to the vehicle operator whenever the headlamp high beams are illuminated. This indicator is controlled by a transistor on the IC circuit board based upon programming and electronic messages received from the BCM over the CAN data bus.

The high beam indicator LED is completely controlled by the IC logic circuit, and that logic will allow this indicator to operate whenever the IC receives a battery current input on the fused B(+) circuit. Therefore, the LED can be illuminated regardless of the ignition switch position. The LED only illuminates when it is provided a path to ground by the IC transistor. The IC will turn ON the high beam indicator for the following reasons:

- High Beam Indicator Lamp-On Message - Each time the cluster receives an electronic high beam indicator lamp-ON message from the BCM the high beam indicator will be illuminated. The high beam indicator remains illuminated until the cluster receives a lamp-OFF message from the BCM, or until the exterior lamp load shedding (battery saver) timed interval expires, whichever occurs first.

The BCM continually monitors electronic messages from the IC and the SmartBeam(R) module on vehicles so equipped to determine the proper headlamp beam control. The BCM activates or deactivates the headlamp high beams then sends the proper lamp-ON or lamp-OFF message back to the IC.

For proper diagnosis of the SmartBeam(R) module, the BCM, the IC, the CAN data bus or the electronic communication related to high beam indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

LOW COOLANT INDICATOR

The coolant low indicator gives an indication to the vehicle operator when the diesel engine coolant level is low. This indicator is controlled by the IC logic circuit based upon programming and electronic messages received over the CAN data bus from the PCM.

The coolant low indicator function of the LCD unit is completely controlled by the IC logic circuit, and that logic will only allow this indicator to operate when the IC receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LCD coolant low indication will always be OFF when the ignition switch is in any position except ON or START. The IC will turn ON the coolant low indicator for the following reasons:

- Coolant Low Indicator Lamp-On Message - Each time the cluster receives an electronic coolant low indicator lamp-ON message from the PCM indicating the engine coolant level is low, the coolant low textual warning and icon are illuminated and a single chime tone is sounded. The coolant low textual warning and icon remain illuminated until the cluster receives a lamp-OFF message from the PCM, or until the ignition switch is turned to the OFF position, whichever occurs first. The chime tone feature will only repeat during the same ignition cycle if the textual warning and icon are cycled OFF and then ON again by the appropriate messages from the PCM.

The PCM continually monitors the engine coolant level switch on the coolant bottle to determine the level of the engine coolant. The PCM then sends the proper lamp-ON or lamp-OFF message to the IC. If the IC turns ON the coolant low indicator and icon due to a low coolant level, it may indicate that the engine or the engine cooling system requires service.

For proper diagnosis of the engine coolant level switch, the PCM, the IC, the CAN data bus or the electronic communication related to coolant low indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

LOW FUEL INDICATOR

The low fuel indicator gives an indication to the vehicle operator when the level of fuel in the fuel tank becomes low. This indicator is controlled by a transistor on the IC circuit board based upon programming and a hard-wired input received by the cluster from the fuel level sending unit on the fuel pump module in the fuel tank. The IC will illuminate the low fuel indicator for about three seconds each time the ignition is turned to the ON position, during the bulb test.

The low fuel indicator LED is completely controlled by the IC logic circuit, and that logic will only allow this indicator to operate when the IC receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED will always be OFF when the ignition switch is in any position except ON or START. The LED only illuminates when it is provided a path to ground by the IC transistor. The IC will turn ON the low fuel indicator for the following reasons:

- Less Than 11 Percent Tank Full Input - The BCM provides a constant current source to the fuel level sending unit, and monitors a return input on a fuel level sense circuit. The resistance through the fuel level sending unit increases, as the fuel level falls, and decreases as the fuel level rises causing changes in the sense input voltage. Each time the fuel level sense input to the BCM indicates the fuel tank is about 11 percent full or less for 10 consecutive seconds and the vehicle speed is zero, or for 60 consecutive seconds and the vehicle speed is greater than zero, a message is sent to the IC, and the gauge needle is moved to the appropriate position on the gauge scale; the low fuel indicator is illuminated' and a single chime tone is sounded. The low fuel indicator remains illuminated until the fuel level sense input indicates that the fuel tank is greater than about 14 percent full for 10 consecutive seconds and the vehicle speed is zero, or for 60 consecutive seconds and the vehicle speed is greater than zero, or until the ignition switch is turned to the OFF position, whichever occurs first. The chime tone feature will only repeat during the same ignition cycle if the low fuel indicator is cycled OFF and then ON again by the appropriate inputs from the fuel level sending unit.
- Less Than Empty Stop Input - Each time the IC receives a fuel level message from the BCM that indicates the fuel level in the fuel tank is less than the E (or Empty) gauge needle stop position for five consecutive seconds, the gauge needle is moved to the low end of the gauge scale and the low fuel indicator is illuminated immediately. This input would indicate that the fuel level sense input to the BCM is a short circuit.
- More Than Full Stop Input - Each time the IC receives a fuel level message from the BCM that indicates the fuel level in the fuel tank is more than the F (or Full) gauge needle stop position for five consecutive seconds, the gauge needle is moved to the low end of the gauge scale and the low fuel indicator is illuminated immediately. This input would indicate that the fuel level sense input to the BCM is an open circuit.

The BCM continually monitors the fuel tank sending unit to determine the level of fuel in the fuel tank. The BCM then sends the proper electronic fuel level message to IC, and other electronic modules in the vehicle over the CAN data bus. The BCM will store a DTC for any fault detected in the fuel level sense circuit.

For proper diagnosis of the fuel tank sending unit, the BCM, the IC, and the CAN data bus or the electronic communication related to low fuel indicator operation or fuel level data processing a diagnostic scan tool is required. Refer to the appropriate diagnostic information.