Part 2

OPERATION

INDICATORS

Indicators are located in various positions within the CCN and are all connected to the CCN electronic circuit board. The various CCN indicators are controlled by different strategies; some receive fused ignition switch output from the CCN circuitry and have a switched ground, while others are grounded through the CCN circuitry and have a switched battery feed. However, all indicators are completely controlled by the CCN microprocessor based upon various hardwired and electronic message inputs. The blue/green indicators located within the VFD unit dim accordingly with the instrument panel dimming. The red indicators within the VFD are at a fixed intensity.

ABS INDICATOR





The ABS indicator indicates to the vehicle operator that the ABS system is faulty or inoperative. The low side driver on the instrument cluster circuit board controls this indicator based upon cluster programming and electronic messages received by the cluster from the Controller Antilock Brake (CAB) over the CAN data bus.

The ABS indicator LED is completely controlled by the instrument cluster logic circuit. That logic allows this indicator to operate only when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED is always off when the ignition switch is in any position except ON or START. The LED illuminates only when it is provided a path to ground by the instrument cluster transistor. The instrument cluster turns on the ABS indicator for the following reasons:

- Bulb Test - Each time the ignition switch is turned to the ON position the ABS indicator illuminates for about three seconds as a bulb test. The entire bulb test is a function of the CAB.
- ABS Lamp-On Message - Each time the cluster receives a lamp-on message from the CAB, the ABS indicator will be illuminates. 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.
- Communication Error - If the cluster receives no lamp-on or lamp-off message from the CAB for five consecutive message cycles, the ABS indicator illuminates. The indicator remains illuminated until the cluster receives a valid message from the CAB, or until the ignition switch is turned to the OFF position, whichever occurs first.
- self Test - Each time the instrument cluster is put through the self test, the ABS indicator turns on and off during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.
- ABS Diagnostic Test - The ABS indicator blinks on and off by lamp-on and lamp-off messages from the CAB during the ABS diagnostic tests.

The CAB continually monitors the ABS circuits and sensors to determine if the system is in good operating condition. The CAB then sends the proper lamp-on or lamp-off message to the instrument cluster. If the CAB sends a lamp-on message after the bulb test, the CAB has detected a system malfunction and/or the ABS system is inoperative. The CAB stores a Diagnostic Trouble Code (DTC) for any malfunction it detects.

AIRBAG INDICATOR





The airbag indicator indicates to the vehicle operator that the airbag system is faulty or inoperative. A transistor on the instrument cluster circuit board controls the indicator based upon cluster programming and electronic messages received by the cluster from the Occupant Restraint Controller (ORC) over the CAN data bus.

The airbag indicator LED is completely controlled by the instrument cluster logic circuit. That logic allows this indicator to operate only when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED is always off when the ignition switch is in any position except ON or START. The LED illuminates only when it is provided a path to ground by the instrument cluster transistor. The instrument cluster illuminates the airbag indicator for the following reasons:

- Bulb Test - Each time the ignition switch is turned to the ON position the airbag indicator illuminates for about six to eight seconds. The entire bulb test is a function of the ORC.
- ORC Lamp-On Message - Each time the cluster receives a lamp-on message from the ORC, the airbag indicator illuminates. The indicator remains illuminated for about twelve seconds, or until the cluster receives a lamp-off message from the ORC.
- Communication Error - If the cluster receives no airbag messages for 10 consecutive message cycles, the airbag indicator illuminates. The indicator remains illuminated until the cluster receives a single lamp-off message from the ORC.
- Self Test - Each time the cluster is put through the self test, the airbag indicator turns on and off during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry. The actuator test illumination of the airbag indicator is a function of the instrument cluster.

The ORC continually monitors the airbag system circuits and sensors to determine if the system is in good operating condition. The ORC then sends the proper lamp-on or lamp-off message to the instrument cluster. If the ORC sends a lamp-on message after the bulb test, the ORC has detected a system malfunction and/or the airbags and seat belt tensioners may not deploy when required, or may deploy when not required. The ORC stores a Diagnostic Trouble Code (DTC) for any malfunction it detects.
BRAKE/PARK BRAKE INDICATOR





The brake indicator indicates to the vehicle operator that the parking brake is applied, or there are certain brake hydraulic system malfunctions as indicated by a low brake hydraulic fluid level condition, or the brake fluid level switch is disconnected. The brake indicator also indicates when certain faults are detected in the ABS. A transistor on the instrument cluster circuit board controls this indicator based upon cluster programming, electronic messages received by the cluster from the CAB over the CAN data bus, and a hardwired input from the park brake switch.

The brake indicator LED is completely controlled by the instrument cluster logic circuit. That logic allows this indicator to operate only when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED is always off when the ignition switch is in any position except ON or START. The LED illuminates only when it is provided a path to ground by the instrument cluster transistor. The instrument cluster illuminates the brake indicator for the following reasons:

- Bulb Test - Each time the ignition switch is turned to the ON position the brake indicator illuminates for about three seconds as a bulb test. The entire bulb test is a function of the CAB.
- Brake Lamp-On Message - Each time the cluster receives a lamp-on message from the CAB, the brake indicator illuminates. The CAB also send brake lamp-on messages as feedback during ABS diagnostic procedures. 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.
- Park Brake Switch Input - Each time the cluster detects ground on the park brake switch sense circuit (park brake switch closed = park brake applied or not fully released) while the ignition switch is in the ON position, and vehicle speed in 8km (4.9 mph) or greater, the brake indicator flashes on and off and a single chime tone will sound. The indicator continues to flash until the park brake switch sense input to the cluster is an open circuit (park brake switch open = park brake fully released), or until the ignition switch is turned to the OFF position, whichever occurs first.
- Self Test - Each time the instrument cluster is put through the self test, the brake indicator will turn on and off during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.

The park brake switch on the park brake pedal mechanism provides a hardwired ground input to the instrument cluster 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 determine if the system is in good operating condition. The CAB then sends the proper lamp-on or lamp-off message to the instrument cluster. If the CAB sends a lamp-on message after the bulb test, the CAB has detected a brake hydraulic system malfunction and/or the ABS system is inoperative. The CAB stores a DTC for any malfunction it detects. The brake/park brake indicator is serviced with the instrument cluster.

CHARGING INDICATOR





The charging indicator indicates to the vehicle operator that the electrical system voltage is too low or too high. A transistor on the instrument cluster circuit board control this indicator based upon cluster programming and electronic messages received by the cluster from the PCM over the CAN data bus.

The charging indicator LED is completely controlled by the instrument cluster logic circuit. That logic allows this indicator to operate only when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the LED is always off when the ignition switch is in any position except ON or START. The LED illuminates only when it is provided a path to ground by the instrument cluster transistor. The instrument cluster illuminates the charging indicator for the following reasons:

- Bulb Test - Each time the ignition switch is turned to the ON position the instrument cluster illuminates the charging indicator for about three seconds as a bulb test.
- Voltage Low Message - Each time the cluster receives a message from the PCM indicating the electrical system voltage is low (less than about 11.5 volts is a charge fail condition), the charging indicator illuminates. The indicator remains illuminated until the cluster receives a message from the PCM indicating the electrical system voltage is normal (greater than about 12.0 volts, but less than 16.0 volts), or until the ignition switch is turned to the Off position, whichever occurs first.
- Voltage High Message - Each time the cluster receives a message from the PCM indicating the electrical system voltage is high (greater than about 16.0 volts), the charging indicator illuminates. The indicator remains illuminated until the cluster receives a message from the PCM indicating the electrical system voltage is normal (less than about 15.5 volts, but greater than 11.5 volts), or until the ignition switch is turned to the Off position, whichever occurs first.
- Self Test - Each time the cluster is put through the self test, the charging indicator turns on and off during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.

The PCM continually monitors the electrical system voltage to control the generator output. If the instrument cluster turns on the charging indicator due to a charge fail or voltage high condition, it may indicate that the charging system requires service. For further diagnosis of the charging indicator or the instrument cluster circuitry that controls the indicator, Testing and Inspection. The charging indicator is serviced with the instrument cluster.

ENGINE TEMPERATURE INDICATOR





The engine temperature indicator indicates to the vehicle operator an engine temperature condition requiring immediate attention. A transistor on the instrument cluster circuit board controls this indicator based upon cluster programming and electronic messages received by the cluster from the PCM over the CAN data bus.

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

- Bulb Test - Each time the ignition switch is turned to the On position the engine temperature indicator illuminates for about three seconds as a bulb test. The entire bulb test is a function of the PCM.
- Engine Temperature High Message - Each time the cluster receives a message from the PCM indicating the engine coolant temperature is above about 125° C (257° F), the engine temperature indicator illuminates and a single chime tone sounds. The indicator remains illuminated until the cluster receives a message from the PCM indicating that the engine coolant temperature is below about 121° C (250° F), or until the ignition switch is turned to the OFF position, whichever occurs first. The chime tone feature repeats during the same ignition cycle only if the engine temperature indicator cycles off and on by the appropriate engine temperature messages from the PCM.
- Self Test - Each time the cluster is put through the self test, the engine temperature indicator turns on and off during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.

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 instrument cluster. For further diagnosis of the engine temperature indicator or the instrument cluster circuitry that controls the LED, Testing and Inspection. If the instrument cluster illuminates 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. The engine temperature indicator is serviced with the instrument cluster.

ELECTRONIC THROTTLE CONTROL INDICATOR





The Electronic Throttle Control (ETC) indicator indicates to the vehicle operator that the ETC system is faulty or inoperative. A transistor on the instrument cluster circuit board controls the ETC indicator based upon cluster programming and electronic messages received by the cluster from the PCM over the CAN data bus.

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

- Bulb Test - Each time the ignition switch is turned to the ON position the ETC indicator illuminates for about fifteen seconds. The entire bulb test is a function of the PCM.
- ETC Lamp-On Message - Each time the cluster receives a lamp-on message from the PCM, the ETC indicator illuminates. The indicator flashes on and off, or illuminates solid, as dictated by the PCM message. The indicator remains illuminated solid or continues to flash for about twelve seconds, or until the cluster receives a lamp-off message from the PCM. If the indicator illuminates solid with the engine running the vehicle usually remains 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.
- Self Test - Each time the cluster is put through the self test, the ETC indicator turned on and off during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry. The actuator test illumination of the ETC indicator is a function of the PCM.

The PCM continually monitors the ETC system circuits and sensors to determines if the system is in good operating condition. The PCM then sends the proper lamp-on or lamp-off message to the instrument cluster. If the PCM sends a lamp-on message after the bulb test, the PCM has detected an ETC system malfunction and/or the ETC system is inoperative. The PCM stores a DTC for any malfunction it detects. The ETC indicator is serviced with the instrument cluster.

FOG LAMP INDICATOR





The fog lamp indicator indicates to the vehicle operator that the optional fog lamps are illuminated. A transistor on the instrument cluster circuit board controls this indicator based upon cluster programming and electronic messages received by the cluster from the FCM over the CAN data bus.

The fog lamp indicator LED is completely controlled by the instrument cluster logic circuit. That logic allows this indicator to operate only when the instrument cluster receives a battery current input on the fused B(+) circuit. Therefore, the LED illuminates regardless of the ignition switch position. The LED illuminates only when it is provided a path to ground by the instrument cluster transistor. The instrument cluster illuminates the fog lamp indicator for the following reasons:

- Fog Lamp-On Message - Each time the cluster receives a fog lamp-on message from the FCM indicating the fog lamp relay is energized, the fog lamp indicator illuminates. The indicator remains illuminated until the cluster receives a fog lamp-off message from the FCM.
- self Test - Each time the cluster is put through the self test, the fog lamp indicator turns on and off again during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.

The instrument cluster continually monitors a hardwired input from the headlamp switch to determine the selected fog lamp switch status. The instrument cluster then sends the proper fog lamp-on and lamp-off messages to the FCM over the CAN data bus. The FCM activates the fog lamp relay then sends the proper fog lamp indicator lamp-on and lamp-off messages to the instrument cluster. For further diagnosis of the fog lamp indicator or the instrument cluster circuitry that controls the indicator, Testing and Inspection. The fog lamp indicator is serviced with the instrument cluster.

HIGH BEAM INDICATOR





The high beam indicator indicates to the vehicle operator that the headlamp high beams are illuminated. The FCM sends a data Bus message for high beam indicator illumination, in turn the CCN takes this data Bus message directive to turn on the indicator.

The high beam indicator LED is completely controlled by the instrument cluster logic circuit. That logic allows this indicator to operate only when the instrument cluster receives a battery current input on the fused B(+) circuit. Therefore, the LED illuminates regardless of the ignition switch position. The LED illuminates only when it is provided a path to ground by the instrument cluster transistor. The instrument cluster illuminates the high beam indicator for the following reasons:

- Self Test - Each time the cluster is put through the self test, the high beam indicator turns on and off during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.

The instrument cluster continually monitors the headlamp switch and the multi-function switch to determine the proper headlamp low beam and high beam control. The instrument cluster then sends the proper low beam and high beam lamp-on and lamp-off messages to the FCM over the CAN data bus and turns the high beam indicator on or off accordingly. For further diagnosis of the high beam indicator or the instrument cluster circuitry that controls the indicator, Testing and Inspection. The high beam indicator is serviced with the instrument cluster.

LOW FUEL INDICATOR





The low fuel indicator indicates to the vehicle operator that the level of fuel in the fuel tank is low. A transistor on the instrument cluster circuit board controls this indicator based upon cluster programming and a hardwired input received by the cluster from the fuel level sending unit on the fuel pump module in the fuel tank.

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

- Bulb Test - Each time the ignition switch is turned to the ON position the low fuel indicator illuminates for about three seconds as a bulb test.
- Less Than Ten 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 ten percent full or less for ten consecutive seconds and the vehicle speed is zero, or for sixty consecutive seconds and the vehicle speed is greater than zero, the fuel gauge needle is moves to about the one-eighth graduation on the gauge scale, the low fuel indicator illuminates, and a single chime tone sounds. The low fuel indicator remains illuminated until the fuel level sense input indicates the fuel tank is greater than about thirteen percent full for ten consecutive seconds and the vehicle speed is zero, or for sixty 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 repeats during the same ignition cycle only if the low fuel indicator cycles off and 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 Empty gauge needle stop position, 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 Full gauge needle stop position if 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.
- Self Test - Each time the cluster is put through the self test, the low fuel indicator turns on and off during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.

The instrument cluster continually monitors the fuel tank sending unit to determine the level of fuel in the fuel tank. The cluster then sends the proper fuel level messages to other electronic modules in the vehicle over the CAN data bus. For further diagnosis of the low fuel indicator or the instrument cluster circuitry that controls the LED, Testing and Inspection. The low fuel indicator is serviced with the instrument cluster.