Part 2

OPERATION


ELECTRONIC THROTTLE CONTROL INDICATOR

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

The ETC indicator LED is completely controlled by the CCN 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 CCN transistor. The CCN will also turn on the ETC indicator for the following reasons:

- ETC Lamp-ON Message - Each time the CCN receives a lamp-on message from the PCM, the ETC indicator will be illuminated. The indicator can be flashed on and off, or illuminated solid, as dictated by the PCM message. The indicator remains illuminated solid or continues to flash for about twelve seconds or until a lamp-off message from the PCM is received, whichever is longer. If the indicator is illuminated solid with the engine running the vehicle will usually remain drivable. If the indicator is flashing with the engine running the vehicle may require towing. A flashing indicator means the ETC system requires immediate service.

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

ENGINE TEMPERATURE INDICATOR

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

The engine temperature indicator LED is completely controlled by the CCN 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 CCN transistor. The engine temperature indicator will also be turned on for the following reasons:

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

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

ESP/BAS INDICATOR

The ESP/BAS indicator gives an indication to the vehicle operator when the Electronic Stability Program (ESP)/Brake Assist System (BAS) has been activated. This indicator is controlled by a transistor on the CCN circuit board based upon programming and electronic messages received from the Controller Antilock Brake (CAB) and the All-Wheel Drive Control Module (AWDCM) over the CAN data bus. The CCN will illuminate the ESP/BAS indicator for about four seconds each time the ignition is turned to the ON position, during the bulb test.

The ESP/BAS 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 CCN will illuminate the ESP/BAS indicator for the following reasons:

- ESP/BAS Indicator Lamp-ON Message - Each time the cluster receives an electronic ESP/BAS indicator lamp-ON message from the CAB indicating that the ESP/BAS system has been activated, the ESP/BAS indicator will be illuminated. The indicator remains illuminated until the cluster receives a lamp-OFF message from the CAB, or until the ignition switch is turned to the OFF position, whichever occurs first.
- ESP Full OFF Textual Message - Each time the cluster receives an electronic ESP Full OFF indicator lamp-ON message from the CAB indicating that the ESP/BAS system has been manually disabled, an ESP Full OFF textual message will appear within the cluster odometer display. The ESP Full OFF textual message remains displayed until the cluster receives a lamp-OFF message from the CAB, or until the ignition switch is turned to the OFF position, whichever occurs first.
- ESP Permanent Disable Textual Message - Each time the cluster receives an electronic ESP Perm anent Disable message from the CAB indicating that the ESP/BAS system has been permanently disabled, an ESP OFF textual message will appear within the cluster odometer display for about 10 seconds each time the ignition switch is turned to the ON position.

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

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

FOG LAMP INDICATOR

The fog lamp indicator gives an indication to the vehicle operator whenever the optional fog lamps are illuminated. This indicator is controlled by a transistor on the CCN circuit board based upon programming and electronic messages from the Total Integrated Power Module (TIPM) over the CAN data bus.

The fog lamp indicator LED is completely controlled by the CCN 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 LED can be illuminated regardless of the ignition switch position. The LED only illuminates when it is provided a path to ground by the CCN transistor. The CCN will turn on the fog lamp indicator for the following reasons:

- Fog Lamp-ON Message - Each time the CCN receives a fog lamp-on message from the TIPM indicating the fog lamp relay is energized, the fog lamp indicator will be illuminated. The indicator remains illuminated until the cluster receives a fog lamp-off message from the TIPM.

The CCN continually monitors a hard-wired input from the headlamp switch to determine the selected fog lamp switch status. The CCN then sends the proper fog lamp-on and lamp-off messages to the TIPM over the CAN data bus. The TIPM activates the fog lamp relay then sends the proper fog lamp indicator lamp-on and lamp-off messages to the CCN.

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

The ECO / ECO-on message will display in the odometer display. The message will appear whenever the vehicle is driven in a fuel efficient manner, if the feature is turned ON by pressing the odometer push-button and toggling through the menu.

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

4WD INDICATOR

The four-wheel drive indicator gives an indication to the vehicle operator when a four-wheel drive (4WD) mode of the transfer case is selected. This indicator is controlled either by the CCN circuit board (domestic market vehicles) or by a transistor on the circuit board (export market vehicles) based upon programming and electronic messages received from the TIPM over the CAN data bus.

The four-wheel drive indicator is completely controlled by the CCN 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 energized by the CCN logic circuit. The CCN will illuminate the four-wheel drive indicator for the following reasons:

- Four-Wheel Drive Indicator Lamp-ON Message - Each time the cluster receives an electronic four-wheel drive indicator lamp-ON message from the TIPM indicating that a four-wheel drive mode is selected, the four-wheel drive indicator is illuminated. The indicator remains illuminated until the cluster receives a lamp-OFF message from the TIPM, or until the ignition switch is turned to the OFF position, whichever occurs first.

The TIPM continually monitors inputs from the four-wheel drive switch to determine the status of the transfer case. The TIPM then sends the proper lamp-ON or lamp-OFF message to the CCN.

GAS CAP INDICATOR

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

The gas cap indicator function of the odometer VFD unit is completely controlled by the CCN 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 odometer VFD gas cap indication will always be OFF when the ignition switch is in any position except ON or START. The CCN will illuminate the gas cap indicator for the following reasons:

- Gas Cap Indicator Lamp-ON Message - Each time the CCN receives an electronic gas cap indicator lamp-ON message from the PCM indicating there is a gross leak in the vapor recovery system, the gas cap indicator will be 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 on board vapor recovery system to determine whether there are air leaks in the system. The PCM then sends the proper lamp-ON or lamp-OFF message to the CCN. If the CCN illuminates the gas cap indicator due to a monitored gross leak in the vapor recovery system, it may indicate that the gas cap has been removed or is improperly installed.

HIGH BEAM INDICATOR

The high beam indicator gives an indication to the vehicle operator whenever the headlamp high beams are illuminated. The TIPM 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 CCN 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 LED can be illuminated regardless of the ignition switch position. The LED only illuminates when it is provided a path to ground by the CCN transistor. The CCN will turn on the high beam indicator for the following reasons:

- High Beam Headlamps-ON Input - Each time the CCN detects a high beam headlamps-on input from the headlamp beam select switch circuitry of the multi-function switch on the washer/beam select switch mux circuit, the headlamp high beams and the high beam indicator will be illuminated. The headlamp high beams and the high beam indicator remain illuminated until the CCN receives a high beam headlamps-off input from the multi-function switch, or until the exterior lamp load shedding (battery saver) timed interval expires, whichever occurs first.

The CCN continually monitors the headlamp switch and the multi-function switch to determine the proper headlamp low beam and high beam control. The CCN then sends the proper low beam and high beam lamp-on and lamp-off messages to the TIPM over the CAN data bus and turns the high beam indicator on or off accordingly.

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 CCN circuit board based upon programming and electronic fuel level messages received from the TIPM over the CAN data bus. 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 CCN 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 CCN transistor. The CCN will illuminate the low fuel indicator for the following reasons:

- Less Than 11 Percent Tank Full Message - The TIPM 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 rises and decreases as the fuel level falls causing changes in the fuel level sense input voltage. The TIPM then sends the appropriate electronic fuel level messages to the cluster. Each time the fuel level messages to the cluster indicate 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 messages indicate 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 messages from the TIPM.
- Less Than Empty Stop Message - Each time the cluster receives a fuel level message indicating 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 TIPM is a short circuit.
- More Than Full Stop Message - Each time the cluster receives a fuel level message indicating 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 TIPM is an open circuit.

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

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 CCN circuit board based upon programming and electronic messages received 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 CCN transistor. The CCN will turn on the low oil pressure indicator for the following reasons:

- Engine Oil Pressure Low Message - Each time the CCN receives a message from the PCM indicating the engine oil pressure is about 4 psi (27.5 kPa) or lower, the low oil pressure indicator will be illuminated. The indicator remains illuminated until the CCN receives a message from the PCM indicating that the engine oil pressure is above about 4 psi (27.5 kPa), or until the ignition switch is turned to the OFF position, whichever occurs first. The CCN will only turn the indicator on in response to an engine oil pressure low message 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 engine oil pressure messages to the CCN.

LOW TIRE PRESSURE INDICATOR

The Tire Pressure Monitor (TPM) indicator gives an indication to the vehicle operator of the status of the TPM system. The TPM indicator is controlled by the CCN circuit board based upon programming and electronic messages received from the Wireless Control Module (WCM) 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 is completely controlled by the CCN's instrument cluster logic circuit, that logic only allow's this indicator to operate when the CCN 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 energized by the instrument cluster logic circuit. The CCN will illuminate the TPM indicator for the following reasons:

- TPM Indicator Lamp-ON Message - Each time the CCN receives an electronic TPM indicator lamp-ON message from the WCM, the indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the WCM message. The indicator remains illuminated until the cluster receives a lamp-OFF message, or until the ignition switch is turned to the OFF position, whichever occurs first.
- Low Tire Textual Message - ON vehicles manufactured for export markets, each time the CCN receives an electronic TPM indicator lamp-ON message from the WCM requesting the TPM indicator be illuminated solid, a LOtIRE textual message will appear within the odometer VFD display. The LOtIRE textual message remains displayed until the CCN receives a lamp-OFF message, or until the ignition switch is turned to the OFF position, whichever occurs first.
- Communication Error - If the CCN receives no TPM lamp-ON or lamp-OFF messages from the WCM for six consecutive seconds, the TPM indicator is illuminated. The indicator remains controlled and illuminated by the CCN until a valid lamp-ON or lamp-OFF message is received from the WCM.