Part - 5

OPERATION

SERVICE PARK ASSIST INDICATOR

The service park assist indicator gives an indication to the vehicle operator when the park assist module has recorded a DTC for a front or rear park assist system circuit or component malfunction. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and electronic messages received by the cluster from the park assist module over the CAN data bus.

The service park assist 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 service park assist indication will always be OFF when the ignition switch is in any position except ON or START. The instrument cluster will turn ON the service park assist indicator for the following reasons:

- Service Park Assist Indicator Lamp-On Message - Each time the cluster receives an electronic service park assist indicator lamp-ON message from the park assist module, the service park assist indicator will be illuminated. The indicator remains illuminated for between three and five seconds, until the cluster receives a lamp-OFF message from the park assist module, 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 park assist module continually monitors the front and rear park assist system circuits and components to determine the condition of the system. The park assist module then sends the proper lamp-ON or lamp-OFF message to the CCN.

For proper diagnosis of the front or rear park assist systems, the park assist module, the CCN, the CAN data bus or the electronic communication related to service park assist indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

SMARTBEAM INDICATOR

The auto high beams (SmartBeam(TM)) indicator gives an indication to the vehicle operator of the system status. 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 Auto High Beams (SmartBeam(TM)) Module (AHBM).

The auto high beams 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 auto high beam indications will always be OFF when the ignition switch is in any position except ON or START. The instrument cluster will turn ON the auto high beams indicator for the following reasons:

- Auto High Beams Status Inactive To Active Message - Each time the cluster receives an electronic auto high beams status inactive to active message from the AHBM while an auto high beams override is not active, the AUTO HIGH BEAMS ON textual message is displayed. The message is displayed for about three seconds, 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.
- Auto High Beams Override From Inactive To Active Message - Each time the cluster receives an electronic auto high beams override from inactive to active message from the AHBM while the auto high beams status is active, the AUTO HIGH BEAMS ON textual message is displayed. The message is displayed for about three seconds, 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.
- Auto High Beams Status Active To Inactive Message - Each time the cluster receives an electronic auto high beams status active to inactive message from the AHBM while an auto high beams override is not active, the AUTO HIGH BEAMS OFF textual message is displayed. The message is displayed for about three seconds, 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.
- Auto High Beams Override From Active To Inactive Message - Each time the cluster receives an electronic auto high beams override from active to inactive message from the AHBM while the auto high beams status is active, the AUTO HIGH BEAMS OFF textual message is displayed. The message is displayed for about three seconds, 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 AHBM continually monitors the CCN to determine the status of the auto high beams system and the status of the auto high beams override to determine the proper outputs to the Front Control Module (FCM). The AHBM then sends the proper lamp-ON or lamp-OFF message to the CCN.

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

TOW/HAUL INDICATOR

The tow/haul indicator gives an indication to the vehicle operator when the OFF position of the tow/haul switch has been selected, disabling the electronically controlled overdrive feature of the automatic transmission. 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 CCN will illuminate the tow/haul indicator for about three seconds each time the ignition is turned to the ON position, during the bulb test.

The tow/haul 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 tow/haul indicator for the following reasons:

- Tow/Haul Indicator Lamp-On Message - Each time the cluster receives an electronic tow/haul indicator lamp-ON message from the PCM indicating that the OFF position of the tow/haul switch has been selected, the indicator will be illuminated. The indicator remains 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 PCM continually monitors the tow/haul switch to determine the proper outputs to the automatic transmission. The PCM then sends the proper lamp-ON or lamp-OFF message to the CCN.

For proper diagnosis of the transmission control system, the PCM, the CCN, the CAN data bus or the electronic communication related to tow/haul indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

TRACTION CONTROL INDICATOR

The traction control indicator gives an indication to the vehicle operator when the ESC/BAS/Traction Control System (TCS) has been activated. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and electronic messages received by the cluster from the CAB over the CAN data bus. The CCN will illuminate the traction control indicator for about four seconds each time the ignition is turned to the ON position, during the bulb test.

The traction control indicator 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 indicator will always be OFF when the ignition switch is in any position except ON or START. The indicator only illuminates when it is provided a path to ground by the instrument cluster circuitry. The instrument cluster will turn ON the traction control indicator for the following reasons:

- Traction Control Indicator Lamp-On Message - Each time the cluster receives an electronic traction control indicator lamp-ON message from the CAB indicating that the ESC/BAS/TCS has been activated, the traction control indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the CAB message. The indicator remains illuminated solid or continues to flash 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.

The CAB continually monitors the traction control switch to determine the proper outputs to the components of the Antilock Brake System (ABS). The CAB then sends the proper lamp-ON or lamp-OFF message to the CCN.

For proper diagnosis of the traction control switch, the ESC/BAS/TCS, the CAB, the CCN, the CAN data bus or the electronic communication related to traction control indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

TRANSMISSION RANGE INDICATOR

The electronic gear selector indicator gives an indication to the vehicle operator of the transmission gear that has been selected with the automatic transmission gear selector lever. This indicator is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received from the PCM over the CAN data bus.

The gear selector indicator information is displayed by the fixed segment LCD display unit soldered onto the instrument cluster electronic circuit board, and the LCD will not display the gear selector indicator information after the ignition switch is turned to the OFF position. Each time the cluster is disconnected from battery current for more than about five minutes, it must configure itself for the automatic transmission type that is in the vehicle once it is reconnected to battery current. The instrument cluster circuitry operates the gear selector indicator to provide the following features:

- Selected Gear Message - Each time the cluster receives an electronic selected gear message from the PCM, brackets [ ] will be illuminated around the appropriate character in the gear selector indicator. The brackets will remain illuminated until the cluster receives a different selected gear message, or until the ignition switch is turned to the OFF position, whichever occurs first.
- Communication Error - If the cluster fails to receive a selected gear message from the PCM within three seconds, the instrument cluster circuitry will display all gear selector positions bracketed (selected) until a valid selected gear message is received or until the ignition switch is turned to the OFF position, whichever occurs first.

The PCM continually monitors a hard-wired multiplex input from the Transmission Range Sensor (TRS), then sends the proper message to the CCN.

For proper diagnosis of the TRS, the PCM, the CCN, the CAN data bus or the electronic communication related to gear selector indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

TRANSMISSION TEMPERATURE INDICATOR

The transmission over-temperature indicator gives an indication to the vehicle operator when the transmission fluid temperature is excessive, which may lead to accelerated transmission component wear or failure. 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 transmission over-temperature 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 transmission over-temperature indication will always be OFF when the ignition switch is in any position except ON or START. The instrument cluster will turn ON the transmission over-temperature indicator for the following reasons:

- Trans Over-Temp Indicator Lamp-On Message - Each time the cluster receives an electronic trans over-temp indicator lamp-ON message from the FCM indicating that the fluid temperature is 135 °C (275 °F) or higher, the transmission over-temperature indicator will be illuminated and a single chime tone is sounded. The indicator remains illuminated for about five seconds, until the cluster receives a lamp-OFF message from the FCM, 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 chime tone feature will only repeat during the same ignition cycle if the indicator is cycled OFF and then ON again by the appropriate lamp-ON and lamp-OFF messages from the FCM.

The FCM continually monitors the transmission temperature sensor to determine the transmission operating condition. The FCM then sends the proper lamp-ON or lamp-OFF message to the CCN. If the instrument cluster illuminates the transmission over-temperature indicator due to a high transmission oil temperature condition, it may indicate that the transmission or the transmission cooling system are being overloaded or that they require service.

For proper diagnosis of the transmission temperature sensor, the FCM, the CCN, the CAN data bus or the electronic communication related to transmission over-temperature indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

TURN SIGNAL INDICATORS

The turn signal indicators give an indication to the vehicle operator that the turn signal (left or right indicator flashing) or hazard warning (both left and right indicators flashing) have been selected and are operating. These indicators are controlled by transistors on the instrument cluster electronic circuit board based upon the cluster programming and electronic messages received from the Front Control Module (FCM) over the CAN data bus.

Each turn signal indicator LED 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, each LED can be illuminated regardless of the ignition switch position. The LED only illuminates when it is provided a path to ground by the instrument cluster transistor. The instrument cluster will turn ON the turn signal indicators for the following reasons:

- Turn Signal Indicator Lamp-On Message - Each time the cluster receives an electronic right or left turn signal-ON message from the FCM over the CAN data bus, the appropriate turn signal indicator will be flashed ON and OFF. The FCM also sends the appropriate electronic message to the cluster to control the flash rate of the turn signal indicators, as well as to control the click rate of an electromechanical relay soldered onto the cluster electronic circuit board that emulates the sound emitted by a conventional turn signal flasher. The turn signal indicators continue to flash ON and OFF until the cluster receives a lamp-OFF message from the FCM, or until the ignition switch is turned to the OFF position, whichever occurs first.
- Hazard Warning Indicator Lamp-On Message - Each time the cluster receives an electronic hazard warning-ON message from the FCM over the CAN data bus, both turn signal indicators will be flashed ON and OFF. The FCM also sends the appropriate electronic messages to the cluster to control the flash rate of the right and left turn signal indicators, as well as to control the click rate of an electromechanical relay soldered onto the cluster electronic circuit board that emulates the sound emitted by a conventional hazard warning flasher. The turn signal indicators continue to flash ON and OFF until the cluster receives a hazard warning-OFF message from the FCM.
- Turn Signal-On Textual Warning Message - When the cluster detects that a turn signal has been active continuously for 1.6 kilometers (1 mile) with the vehicle speed greater than 22 kilometers-per-hour (15 miles-per hour) a TURN SIGNAL ON textual message and flashing right or left turn signal icon will appear within the instrument cluster re-configurable dot matrix display and a chime tone will be sounded.
- Lamp Out Mode - If the FCM detects an ineffective turn signal lamp or circuit, it increases the flash rate for the remaining operative turn signals and sends an electronic message to the instrument cluster. The instrument cluster then increases the flash rate of the turn signal indicators and the click rate of the electromechanical relay to provide an indication of the problem to the vehicle operator.

The CCN continually monitors the electronic messages from the FCM to determine the proper turn signal and hazard warning indicator operation.

For proper diagnosis of the turn signal and hazard warning system, the multi-function switch, the FCM, the CCN, the CAN data bus or the electronic communication related to turn signal indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

UPSHIFT INDICATOR

The upshift indicator gives an indication to the vehicle operator that the engine speed is nearing its limit and a transmission upshift is necessary to prevent engine over speeding. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and electronic messages received by the cluster from the Transmission Control Module (TCM) over the CAN data bus.

The upshift 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 upshift indication will always be OFF when the ignition switch is in any position except ON or START. The instrument cluster will turn ON the upshift indicator for the following reasons:

- Upshift Indicator Lamp-On Message - Each time the cluster receives an electronic upshift indicator lamp-ON message from the TCM indicating that the engine speed is nearing its limit, the upshift indicator is illuminated. The indicator remains illuminated for about five seconds, until the cluster receives a lamp-OFF message from the TCM, 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 TCM continually monitors the engine speed and the Transmission Range Sensor (TRS) to determine the proper control outputs for the engine fuel, ignition and emissions systems. The TCM then sends the proper lamp-ON or lamp-OFF message to the CCN.

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

WASHER FLUID INDICATOR

The washer fluid indicator gives an indication to the vehicle operator that the fluid level in the washer reservoir is low. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and electronic messages received by the cluster from the Front Control Module (FCM) over the CAN data bus.

The washer fluid 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 washer fluid indication will always be OFF when the ignition switch is in any position except ON or START. The instrument cluster will turn ON the washer fluid indicator for the following reasons:

- Washer Fluid Indicator Lamp-On Message - Each time the cluster receives an electronic washer fluid indicator lamp-ON message from the FCM indicating that a low washer fluid condition has been detected for 60 consecutive seconds, the washer fluid indicator is illuminated and a single chime tone is sounded. The indicator remains illuminated until the cluster receives lamp-OFF messages for 60 consecutive seconds from the FCM, 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 washer fluid indicator is cycled OFF and then ON again by the appropriate lamp-ON and lamp-OFF messages from the FCM.

The FCM continually monitors the washer fluid level switch in the washer reservoir to determine the level of the washer fluid. The FCM then sends the proper lamp-ON or lamp-OFF message to the CCN.

For proper diagnosis of the washer fluid level switch, the FCM, the CCN, the CAN data bus or the electronic communication related to washer fluid indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

The hard-wired indicator inputs may be diagnosed using conventional diagnostic tools and procedures. However, the CCN circuitry and electronic CAN or LIN data bus message controlled indicators are diagnosed using the self-diagnostic CCN Self test. Testing and Inspection for more information. For proper testing of the CAN or LIN data bus and the electronic data bus message inputs to the CCN that control each indicator requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.