Part 1

OPERATION

Indicators are located in various locations within the Instrument Cluster (IC) and are all connected to the electronic circuit board. All of the indicators are completely controlled by the IC. The various indicators are controlled by different strategies; some receive fused ignition output from the IC circuitry and have a switched ground, while others are grounded through the IC circuitry and have a switched battery feed. However, most are controlled by (CAN) or Local Interface Network (LIN) data bus messages from other electronic modules in the vehicle while others are controlled by a combination of hard wired inputs, electronic messaging and IC programming. If the IC loses CAN data bus communication, the IC circuitry will automatically turn ON the Malfunction Indicator Lamp (MIL) until CAN data bus communication is restored.

In addition, certain indicators in this IC are automatically or self-configured. This feature allows the configurable indicators to be enabled by the IC circuitry for compatibility with certain optional equipment. These indicators are enabled or disabled by an electronic configuration message sent to the IC by the Body Control Module (BCM) (also known as the Common Body Controller/CBC). The BCM defaults for the Antilock Brake System (ABS) and the airbag indicators is enabled. These configuration settings must be programmatically disabled in the BCM using a diagnostic scan tool for vehicles that do not have this equipment. The automatically or self-configured indicators remain latent in the IC at all times and will be active only when the IC receives the appropriate CAN or LIN bus message inputs for that optional system or equipment.

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

Below are brief explanations of the indicators available on this vehicle. More detailed information may be available elsewhere in this service information, located within the section covering the system or component that control or influence the illumination of that indicator. The indicators, the TFT display, the LED units as well as the gauges are only serviceable with the IC as an assembly. The cluster lenses and the hood and mask assembly may be serviced separately from the IC.

ABS INDICATOR

The ABS indicator gives an indication to the vehicle operator when the ABS system, or a circuit or component of the system is ineffective. 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 over the CAN data bus. The IC will illuminate the ABS indicator for about three seconds as a bulb test each time the ignition switch status transitions to ON.

The ABS 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 output (run-start) circuit. Therefore, the LED will always be OFF when the status of the ignition switch is anything 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 ABS indicator for the following reasons:

- ABS Indicator Lamp-On Message - Each time the IC receives an electronic ABS indicator lamp-ON message from the CAB, the ABS indicator will be illuminated. The indicator remains illuminated until the IC receives a lamp-OFF message from the CAB, or until the ignition switch status transitions to OFF, whichever occurs first.
- Communication Error - If the IC receives no lamp-ON or lamp-OFF messages from the CAB for five consecutive message cycles, the ABS indicator is illuminated. The indicator remains illuminated until the IC receives a valid message from the CAB, or until the ignition switch status transitions to OFF, whichever occurs first.
- ABS Diagnostic Test - The ABS indicator is blinked ON and OFF by lamp-ON and lamp-OFF messages from the CAB during the performance of the ABS diagnostic tests.

The CAB continually monitors the ABS circuits and sensors to decide whether the system is in good operating condition. The CAB then sends the proper lamp-ON or lamp-OFF message to the IC. If the CAB sends a lamp-ON message after the bulb test, it indicates that the CAB has detected a system malfunction or that the ABS system has become ineffective. The CAB will store a DTC for any malfunction it detects. Each time the ABS indicator fails to light due to an open or short in the IC ABS indicator circuit, the IC sends a message notifying the CAB of the condition, then the IC and the CAB will each store a DTC and the IC will flash the brake indicator ON and OFF as a backup to notify the vehicle operator.

For proper diagnosis of the anti-lock brake system, the CAB, the IC, the CAN data bus or the electronic communication related to ABS indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

AIRBAG INDICATOR

The airbag indicator gives an indication to the vehicle operator when the airbag system, or a circuit or component of the system is ineffective. The airbag indicator is controlled by a transistor on the IC circuit board based upon programming and electronic messages received by the IC from the Occupant Restraint Controller (ORC) over the CAN data bus. The IC will illuminate the airbag indicator for about six seconds as a bulb test each time the ignition switch status transitions to ON.

The airbag 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 output (run-start) circuit. Therefore, the LED will always be OFF when the ignition switch status is anything 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 airbag indicator for the following reasons:

- Airbag Indicator Lamp-On Message - Each time the IC receives an electronic airbag indicator lamp-ON message from the ORC, the airbag indicator will be illuminated. The indicator remains illuminated for about 12 seconds or until the IC receives a lamp-OFF message from the ORC, whichever is longer. This indicator will also be extinguished when the ignition switch status transitions to OFF.
- Communication Error - If the IC receives no lamp-ON or lamp-OFF messages from the ORC for 10 consecutive message cycles, the airbag indicator is illuminated. The indicator remains illuminated until the IC receives a single lamp-OFF message from the ORC.

The ORC continually monitors the airbag system circuits and sensors to decide whether the system is in good operating condition. The ORC then sends the proper lamp-ON or lamp-OFF message to the IC. If the ORC sends a lamp-ON message after the bulb test, it indicates that the ORC has detected a system malfunction or that the airbags and seat belt tensioners may not deploy when required, or may deploy when not required. The ORC will store a DTC for any malfunction it detects. Each time the airbag indicator fails to illuminate due to an open or short in the IC airbag indicator circuit, the IC sends a message notifying the ORC of the condition, then the IC and the ORC will each store a DTC.

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

AJAR INDICATORS

The ajar indicators give an indication to the vehicle operator that one or more of the passenger compartment doors or the liftgate may be open or not completely latched. These indicators are controlled by a transistor on the IC circuit board based upon programming and electronic messages received by the IC from the Body Control Module (BCM) over the CAN data bus. The BCM monitors hard-wired inputs from the door and liftgate ajar switches.

The ajar indicator function of the TFT electronic display 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 ajar indications can occur regardless of the ignition switch position. The IC will turn ON an ajar indicator for the following reasons:

- Ajar Indicator Lamp-On Message - Each time the IC receives an electronic door ajar indicator lamp-on or liftgate ajar indicator lamp-on message from the BCM indicating that a door or the liftgate or a combination of these is open or not completely latched, the appropriate ajar textual message and icons will be illuminated. If the IC detects a vehicle speed input greater than zero (kilometers or miles-per-hour) while the ignition switch status is ON or START, the ajar indication will be accompanied by a single chime tone. When the ignition switch status is anything except ON or START, any and all ajar indications will time out after about five minutes.

The ajar switches on the door and liftgate latch mechanisms provide hard-wired ground inputs to the BCM circuitry through the ajar switch sense circuits whenever a door or the liftgate is open or not completely latched. The BCM continually monitors the door and liftgate ajar switches to determine the status of the doors and liftgate, then sends the proper electronic ajar indicator lamp-on or lamp-off message to the IC.

The hard wired ajar switch inputs to the BCM may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. For proper diagnosis of 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.

BRAKE/PARK BRAKE INDICATOR

The brake indicator gives an indication to the vehicle operator when the parking brake is applied, when there are certain brake hydraulic system malfunctions as indicated by a low brake hydraulic fluid level condition or when the brake fluid level switch is disconnected. The brake indicator can also give an indication when certain faults are detected in the Antilock Brake System (ABS). This indicator is controlled by a transistor on the IC circuit board based upon programming and electronic messages received by the IC from the CAB or the Body Control Module (BCM) over the CAN data bus. The BCM monitors the hard wired input from the park brake switch. The IC will illuminate the brake indicator for about three seconds as a bulb test each time the ignition switch status transitions to ON.

The brake 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 output (run-start) circuit. Therefore, the LED will always be OFF when the ignition switch status anything 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 brake indicator for the following reasons:

- Brake Indicator Lamp-On Message - Each time the IC receives an electronic brake indicator lamp-ON message from the CAB, the brake indicator will be illuminated. The CAB may also send lamp-ON messages as feedback during ABS diagnostic procedures. The indicator remains illuminated until the IC receives a lamp-OFF message from the CAB or until the ignition switch status transitions to OFF, whichever occurs first.
- Low Brake Fluid Textual Warning Message - When the CAB detects a low brake fluid level input from the brake fluid level switch, it will send an electronic textual warning request message requesting the IC display a textual warning message. Each time the IC receives this message from the CAB, a LOW BRAKE FLUID LEVEL textual message will appear within the IC electronic display to accompany brake indicator illumination. This message indicates that the CAB has detected a low brake fluid level condition in the brake master cylinder or that there is a problem in the brake fluid level switch or circuits.
- Park Brake Switch Input - Each time the IC receives an electronic brake indicator lamp-FLASH message from the BCM, the brake indicator will be flashed ON and OFF. While the ignition switch status is ON, the BCM monitors the park brake switch through the park brake switch sense circuit (park brake switch closed = park brake applied or not fully released). The indicator continues to flash until the park brake switch sense input to the BCM is an open circuit (park brake switch open = park brake fully released), or until the ignition switch status transitions to OFF, whichever occurs first.
- Antilock Brake System (ABS) Indicator Backup - If the IC detects a fault in the ABS indicator circuit it will send a message indicating the fault to the CAB, then flash the brake indicator ON and OFF. The IC will continue to flash the brake indicator until the ABS indicator circuit fault is resolved, or until the ignition switch status transitions to OFF, whichever occurs first.

The park brake switch on the park brake lever mechanism provides a hard-wired ground input to the BCM circuitry through the park brake switch sense circuit whenever the park brake is applied or not fully released. The CAB continually monitors the ABS system circuits and sensors, including the brake fluid level switch on the brake master cylinder reservoir, to decide whether the system is in good operating condition. The CAB then sends the proper lamp-ON, lamp-OFF or lamp-FLASH message to the IC. If the CAB sends a lamp-ON message after the bulb test, it indicates that the CAB has detected a brake hydraulic system malfunction or that the ABS system has become ineffective. The CAB will store a DTC for any malfunction it detects.

The hard wired park brake switch input to the BCM may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. For proper diagnosis of the brake fluid level switch, the ABS, the BCM, the CAB, the IC, the CAN data bus or the electronic communication related to brake indicator operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

CHANGE OIL INDICATOR

The change oil indicator gives an indication to the vehicle operator when a duty-cycle algorithm contained within the software of the PCM determines that a recommended oil change interval has been attained. 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 change oil indicator function of the IC electronic display 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 output (run-start) circuit. Therefore, the change oil indication will always be OFF when the ignition switch status is anything except ON or START. The IC will turn ON the change oil indicator for the following reasons:

- Change Oil Indicator Lamp-On Message - Each time the ignition switch status transitions to ON and the IC receives an electronic change oil indicator lamp-ON message from the PCM indicating that a duty-cycle based recommended oil change interval has been attained, the change oil indicator will be illuminated for about ten seconds, until the IC arbitrator logic determines that another display request has priority, or until the ignition switch status transitions to OFF, whichever occurs first.
- Change Oil Indicator Reset Procedure - Once an engine oil change has been completed, the PCM duty cycle counters can be reset using the following procedure. Set the ignition switch status to ON, but DO NOT start the engine. Slowly depress and release the accelerator pedal fully three times within ten seconds. The IC will display a textual OIL CHANGE RESET message. Set the ignition switch status to OFF. If the change oil indicator illuminates the next time the engine is started, repeat this procedure.

The PCM continually monitors numerous sensor inputs to determine the duty-cycles to which the engine is being subjected. A pre-programmed algorithm within the PCM then determines when to send the proper lamp-ON or lamp-OFF message to the IC.

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

CHARGING INDICATOR

The charging indicator gives an indication to the vehicle operator when the electrical system voltage is too low or too high. This indicator is controlled by a transistor on the IC circuit board based upon programming and electronic messages received by the IC from the PCM over the CAN data bus. The IC will illuminate the charge indicator for about three seconds as a bulb test each time the ignition switch status transitions to ON.

The charging 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 output (run-start) circuit. Therefore, the LED will always be OFF when the ignition switch status is anything 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 charging indicator for the following reasons:

- Voltage Low Message - Each time the IC receives an electronic system voltage message from the PCM indicating the voltage is low (less than about 11.5 volts is a charge fail condition), the charging indicator will be illuminated. The indicator remains illuminated until the IC receives a message from the PCM indicating the voltage is normal (greater than about 12.0 volts, but less than 16.0 volts), or until the ignition switch status transitions to OFF, whichever occurs first.
- Voltage High Message - Each time the IC receives an electronic system voltage message from the PCM indicating the voltage is high (greater than about 16.0 volts), the charging indicator will be illuminated. The indicator remains illuminated until the IC receives a message from the PCM indicating the voltage is normal (less than about 15.5 volts, but greater than 11.5 volts), or until the ignition switch status transitions to OFF, whichever occurs first.

The PCM continually monitors the electrical system voltage to control the generator output. The PCM then sends the proper messages to the IC. If the IC turns ON the charging indicator due to a charge fail or voltage high condition, it may indicate that the charging system requires service.

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

CHECK GAUGES INDICATOR

The check gauges indicator gives an indication to the vehicle operator when the engine coolant temperature gauge indicates the coolant temperature is high or critical. 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 check gauges indicator function of the electronic display 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 output (run-start) circuit. Therefore, the check gauges indication will always be OFF when the ignition switch status is anything except ON or START. The IC will turn ON the check gauges indicator for the following reasons:

- Engine Temperature High or Critical Message - Each time the IC receives an electronic engine coolant temperature message from the PCM indicating the temperature is high or critical the engine coolant temperature gauge needle is moved to the appropriate position at the high end of the gauge scale, the check gauges textual warning is displayed, and a single chime tone is sounded. The check gauges textual warning remains illuminated until the IC receives a message from the PCM indicating that the temperature is below the high end of normal, until the IC arbitrator logic determines that another display request has priority, or until the ignition switch status transitions to OFF, whichever occurs first. The chime tone feature will only repeat during the same ignition cycle if the check gauges textual warning is cycled OFF and then ON again by the appropriate 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 messages to the IC. If the IC turns on the check gauges indicator due to a high or critical engine temperature gauge reading, it may indicate that the engine or the engine cooling system requires service.

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

CRUISE INDICATOR

The cruise indicator gives the vehicle operator an indication when the speed control system is ON, regardless of whether the speed control is engaged. This indicator is controlled by the IC circuit board based upon programming and electronic messages received by the IC from the PCM over the CAN data bus.

The cruise indicator LED is completely controlled by the IC logic circuit, and that logic only allows this indicator to operate when the IC receives a battery current input on the fused ignition output (run-start) circuit. Therefore, the LED is always be OFF when the ignition switch status is anything 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 cruise indicator for the following reasons:

- Cruise Indicator Lamp-On Message - Each time the IC receives an electronic cruise indicator lamp-on message from the PCM indicating the speed control system is ON, the cruise indicator is illuminated. The indicator remains illuminated until the IC receives a lamp-off message from the PCM, or until the ignition switch status transitions to OFF, whichever occurs first.

The PCM continually monitors the speed control switches to determine the appropriate outputs to control the vehicle speed. The PCM then sends the proper lamp-on or lamp-off message to the IC.

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