Part - 3

OPERATION

LIFTGATE AJAR INDICATOR

The power liftgate indicator gives an indication to the vehicle operator of the system status or when the system has been automatically disabled. This indicator is controlled by the CCN logic circuit based upon programming and electronic messages received over the CAN data bus from the Power LiftGate Module (PLGM).

The power liftgate indicator function of the LCD display unit is completely controlled by the instrument cluster logic circuit, and that logic will allow this indicator to operate whenever the instrument cluster receives a battery current input on the fused B(+) circuit. Therefore, the LCD power liftgate indications can be illuminated regardless of the ignition switch position. The instrument cluster will turn ON the power liftgate indicator for the following reasons:

- Unlock To Operate Message - Each time the CCN receives an electronic unlock to operate message from the PLGM, the UNLOCK TO OPERATE textual message is displayed. The message is displayed for about three seconds or until the cluster arbitrator logic determines that another display request has priority, whichever occurs first.
- Put In Park To Operate Message - Each time the CCN receives an electronic put in PARK to operate message from the PLGM, the PUT IN PARK TO OPERATE textual message is displayed. The message is displayed for about three seconds or until the cluster arbitrator logic determines that another display request has priority, whichever occurs first.
- Function Disabled Message - Each time the CCN receives an electronic function disabled message from the PLGM, the FUNCTION DISABLED textual message is displayed. The message is displayed for about three seconds or until the cluster arbitrator logic determines that another display request has priority, whichever occurs first.
- Close Liftgate Glass Message - Each time the CCN receives an electronic close liftgate glass message from the PLGM, the CLOSE LIFTGLASS textual message is displayed. The message is displayed for about three seconds or until the cluster arbitrator logic determines that another display request has priority, whichever occurs first.
- Obstacle Detected Message - Each time the CCN receives an electronic obstacle detected message from the PLGM, the OBSTACLE DETECTED textual message is displayed. The message is displayed for about three seconds or until the cluster arbitrator logic determines that another display request has priority, whichever occurs first.
- Manually Close To Operate Message - Each time the CCN receives an electronic manually close to operate message from the PLGM, the MANUAL CLOSE TO OPERATE textual message is displayed. The message is displayed for about three seconds or until the cluster arbitrator logic determines that another display request has priority, whichever occurs first.

The PLGM continually monitors the power liftgate inputs to determine the proper outputs to the power liftgate components. The PLGM then sends the proper lamp-ON or lamp-OFF message to the CCN.

For proper diagnosis of the power liftgate, the PLGM, the CCN, the CAN data bus or the electronic communication related to power liftgate 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 instrument cluster logic circuit based upon cluster programming and electronic messages received over the CAN data bus from the PCM.

The coolant low indicator function of the LCD display unit is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster 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 instrument cluster 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 CCN. If the instrument cluster 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 CCN, 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 instrument cluster circuit board based upon cluster 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 CCN 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 instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster 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 instrument cluster transistor. The instrument cluster will turn ON the low fuel indicator for the following reasons:

- Less Than 11 Percent Tank Full Input - The cluster 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 cluster 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, 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 cluster receives a fuel level sense input 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 cluster is a short circuit.
- More Than Full Stop Input - Each time the cluster receives a fuel level sense input 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 cluster is an open circuit.

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

For proper diagnosis of the fuel tank sending unit, the CCN, 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.

LOW OIL PRESSURE INDICATOR

The low oil pressure indicator gives an indication to the vehicle operator when the engine oil pressure reading reflects a condition requiring immediate attention. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the PCM over the CAN data bus.

The low oil pressure indicator LED is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster 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 instrument cluster transistor. The instrument cluster will turn ON the low oil pressure indicator for the following reasons:

- Engine Oil Pressure Low Message - Each time the cluster receives an electronic engine oil pressure message from the PCM indicating the pressure is about 6.9 kPa (1 psi) or lower, the low oil pressure 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 flashing until the cluster receives a message from the PCM indicating that the pressure is above about 6.9 kPa (1 psi), or until the ignition switch is turned to the OFF position, whichever occurs first. The cluster will only turn the indicator ON in response to low engine oil pressure if the engine speed is greater than zero.

The PCM continually monitors the engine oil pressure sensor to determine the engine oil pressure. The PCM then sends the proper messages to the CCN. If the CCN turns ON the indicator after the bulb test, it may indicate that the engine or the engine oiling system requires service.

For proper diagnosis of the engine oil pressure sensor, the PCM, the CCN, the CAN data bus or the electronic communication related to low oil pressure indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

LOW TIRE PRESSURE INDICATOR

The Tire Pressure Monitor (TPM) indicator gives an indication to the vehicle operator of the status of the TPM system. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Wireless Ignition Node (WIN) over the CAN data bus. The CCN will illuminate the TPM indicator for about three seconds each time the ignition is turned to the ON position, during the bulb test

The TPM indicator LED is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster 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 provide a path to ground by the instrument cluster transistor. The instrument cluster will turn ON the TPM indicator for the following reasons:

- TPM Indicator Lamp-On Message - Each time the cluster receives an electronic TPM indicator lamp-ON message from the WIN, the TPM indicator or the TIRE LOW PRESSURE textual message will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the WIN message. The indicator or textual message remains illuminated until the cluster receives a lamp-OFF message from the WIN, or until the ignition switch is turned to the OFF position, whichever occurs first.
- TPM Textual Warning Message - When the WIN 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 textual warning request message from the WIN, a SERVICE TIRE PRESS. SYSTEM textual message will appear within the cluster re-configurable dot matrix display to accompany a flashing TPM indicator or to replace the TPM TIRE LOW PRESSURE textual message. This message indicates that the WIN has detected a problem in one of the TPM system components.
- TPM Low Pressure Message - On vehicles equipped with the optional premium version of the TPM system, each time the cluster receives an electronic low pressure message from the WIN, a LEFT FRONT, RIGHT FRONT, LEFT REAR or RIGHT REAR LOW PRESSURE textual message will appear within the cluster re-configurable dot matrix display to accompany a solid TPM indicator. If the vehicle is equipped with a full-sized matching spare tire and wheel assembly, an electronic spare low pressure message from the WIN to the cluster will cause a SPARE LOW PRESSURE textual message will appear in the re-configurable display, but the TPM indicator will not illuminate. This message indicates that the WIN has received a low tire pressure input from the tire pressure sensor in the identified location on the vehicle. The premium TPM system is not offered in markets where rear fog lamps are an available option.
- Communication Error - If the cluster receives no TPM lamp-ON or lamp-OFF messages from the WIN for six consecutive seconds, the TPM indicator is illuminated by the instrument cluster. The indicator remains controlled and illuminated by the cluster until a valid lamp-ON or lamp-OFF message is received from the WIN.

The WIN performs a self-test each time the ignition switch is turned to the ON position to decide whether the TPM system is in good operating condition and whether the tire inflation pressures are too high or too low. The WIN then sends the proper lamp-ON or lamp-OFF message to the CCN. If the instrument cluster turns ON the TPM indicator after the bulb test, it indicates that the inflation pressure of a tire is too low or that a malfunction has occurred and the TPM system is ineffective.

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

MALFUNCTION INDICATOR LAMP

The Malfunction Indicator Lamp (MIL) gives an indication to the vehicle operator when the PCM has recorded a DTC for an On-Board Diagnostics II (OBDII) emissions-related circuit or component malfunction. The MIL is controlled by a transistor on the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the PCM over the CAN data bus. The CCN will illuminate the MIL indicator for about fifteen seconds each time the ignition is turned to the ON position, during the bulb test.

The MIL LED is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster 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 instrument cluster transistor. The instrument cluster will turn ON the MIL for the following reasons:

- MIL Lamp-On Message - Each time the cluster receives an electronic MIL lamp-ON message from the PCM, the indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the PCM message. For some DTCs, if a problem does not recur, the PCM will send a lamp-OFF message automatically. Other DTCs may require that a fault be repaired and the PCM be reset before a lamp-OFF message will be sent. For more information on the PCM, and the DTC set and reset parameters, Emissions Control - Operation.
- Communication Error - If the cluster receives no lamp-ON or lamp-OFF messages from the PCM for 10 consecutive message cycles, the MIL is illuminated by the instrument cluster to indicate a loss of bus communication. The indicator remains controlled and illuminated by the cluster until a valid message is received from the PCM.

The PCM continually monitors the fuel and emissions 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 CCN. If the CCN turns ON the MIL after the bulb test, it may indicate that a malfunction has occurred and that the fuel and emissions systems may require service.

For proper diagnosis of the fuel and emissions systems, the PCM, the CCN, the CAN data bus or the electronic communication related to MIL operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

MEMORY SYSTEM INDICATOR

The memory system indicator gives an indication to the vehicle operator of the system status or when the system has been automatically disabled. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and electronic messages received over the CAN data bus from the Memory Seat Module (MSM).

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

- Memory Set Message - Each time the cluster receives an electronic memory set message from the MSM, the appropriate MEMORY #1 POSITIONS SET or MEMORY #2 POSITIONS SET textual message is displayed. The message is displayed 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.
- Memory Recall Message- Each time the cluster receives an electronic memory recall message from the MSM, the appropriate DRIVER 1 MEMORY or DRIVER 2 MEMORY textual message is displayed. The message is displayed 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.
- Seatbelt Buckled Message - Each time the cluster receives an electronic seatbelt buckled memory system lockout message from the MSM, the MEMORY SYSTEM DISABLED and SEATBELT BUCKLED textual messages and icon are cycled. The two parts of the message are cycled about every three seconds until the MSM sends an electronic message to cancel the memory system lockout event, 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.
- Vehicle Not In Park Message - Each time the cluster receives an electronic vehicle not in Park memory system lockout message from the MSM, the MEMORY SYSTEM DISABLED and VEHICLE NOT IN PARK textual messages are cycled. The two parts of the message are cycled about every three seconds until the MSM sends an electronic message to cancel the memory system lockout event, until the cluster programming or another request requires a different LCD display, or until the ignition switch is turned to the OFF position, whichever occurs first.

The MSM continually monitors inputs from the seatbelt switch through the CCN, the Driver Door Module (DDM), the Wireless Ignition Node (WIN), the PCM and, if equipped, the Transmission Control Module (TCM) to determine the proper outputs to the memory system components. The MSM then sends the proper lamp-ON or lamp-OFF message to the CCN.

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

No BUS INDICATOR

The no-bus indicator gives an indication to the vehicle operator when the electronic communication data bus is ineffective. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and electronic messages not being received over the CAN data bus from the Front Control Module (FCM).

The no-bus indicator function of the odometer LCD unit is completely controlled by the instrument cluster logic circuit. This logic only allows the indicator to operate when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the odometer LCD no-bus indicator is always off when the ignition switch is in any position except ON or START. The instrument cluster turns ON the no bus indicator for the following reasons:

- No Electronic Communication Messages - Each time the ignition switch is turned to the ON position and the cluster does not receive electronic communication messages over the CAN data bus, the no-bus indicator illuminates. The indicator remains illuminated until CAN bus communication is restored or until the ignition switch turns to the OFF position, whichever occurs first.

The CCN continually monitors the CAN data bus to determine the status of many sensors and systems throughout the vehicle. If bus communication is interrupted, the CCN cannot provide accurate displays and outputs.

Use a diagnostic scan tool is required for proper diagnosis of the no-bus indicator, the CCN, the CAN data bus or the electronic communication related to no-bus indicator operation. Refer to the appropriate diagnostic information.

No FUSE INDICATOR

The no fuse indicator gives an indication to the vehicle operator when the Ignition Off Draw (IOD) fuse is ineffective or is not installed. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and electronic messages received over the CAN data bus from the Front Control Module (FCM).

The no fuse indicator function of the LCD display unit is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LCD no fuse indication will always be OFF when the ignition switch is in any position except ON or START. The instrument cluster will turn ON the no fuse indicator for the following reasons:

- No Fuse Indicator Lamp-On Message - Each time the ignition switch is turned to the ON position and the cluster receives an electronic no fuse indicator lamp-ON message from the FCM indicating that the IOD fuse is missing or ineffective, the no fuse indicator will be illuminated. The indicator remains illuminated for about three seconds, until the IOD fuse is installed, 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.

The FCM continually monitors the IOD circuit to determine the status of the IOD fuse, then sends the proper lamp-ON or lamp-OFF message to the CCN over the CAN data bus.

For proper diagnosis of the no fuse indicator, the FCM, the CCN, the CAN data bus or the electronic communication related to no fuse indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.