Part 2

OPERATION (Continued)

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 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 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 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 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 Permanent 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 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 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 message will display below the outside temperature in the EVIC display. The message will appear whenever the vehicle is driven in a fuel efficient manner, if the feature is turned ON using the customer programmable feature within the EVIC display menu.

On base model vehicle, an ECO or ECO-on message will be displayed within the odometer display when selected by the vehicle operator. The fuel saver feature can be selected 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 INDICATORS

The four-wheel drive indicators 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 indicators are 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 indicators will always be OFF when the ignition switch is in any position except ON or START. The indicators only illuminate when it is energized by the 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, a four-wheel drive indicator is illuminated. That 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 instrument cluster 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 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 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.