Part 3

OPERATION - RHD

DOOR AJAR INDICATOR

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 the instrument cluster logic circuit based upon cluster programming and electronic ajar switch status messages received by the cluster from the TIPM over the CAN data bus.

The ajar indicator function of the odometer or Electronic Vehicle Information Center (EVIC) 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 B(+) circuit. Therefore, the VFD ajar indications can occur regardless of the ignition switch position. The instrument cluster will turn ON the ajar indicator for the following reasons:

- Ajar Switch Message Input - Each time the instrument cluster receives an electronic door or liftgate ajar switch status message indicating that a door, the liftgate or any combination of these is open or not completely latched with the ignition switch in any position, the appropriate ajar indication will be illuminated. If the cluster detects a vehicle speed input greater than zero (kilometers or miles-per-hour) while the ignition switch is in the ON or START positions, the ajar indication will be accompanied by a single chime tone. When the ignition switch is in any position except ON or START, any and all ajar indications will time out after about five minutes.

The TIPM continually monitors the door and liftgate ajar switches to determine the status of the doors and liftgate. The TIPM then sends the proper ajar switch status messages to the instrument cluster.

ESP OFF INDICATOR

The ESP OFF indicator gives an indication to the vehicle operator that the Electronic Stability Program (ESP) system has been manually disabled. 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 CAB and the Transmission Control Module (TCM) over the CAN data bus.

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

- ESP OFF Indicator Lamp-On Message - Each time the cluster receives an electronic ESP OFF indicator lamp-ON message from the CAB indicating that the ESP system has been manually disabled by depressing the ESP OFF switch button in the instrument panel switch pod, the ESP OFF 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.

The instrument cluster continually monitors the status of the ESP OFF switch over a LIN data bus circuit to determine the requested operating mode for the ESP system. The instrument cluster then sends an electronic ESP OFF switch status message to the CAB over the CAN data bus. The CAB then sends the proper lamp-ON or lamp-OFF message back to the instrument cluster, confirming the current operating mode of the ESP system.

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 instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the CAB and the TCM over the CAN data bus.

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. Each time the ignition switch is turned to the ON position the ESP/BAS indicator is illuminated for about four seconds as a bulb test. The instrument cluster will turn ON 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 OFF textual message will appear within the cluster odometer display. The ESP 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.

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 instrument cluster.

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 instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the PCM/ECM over the CAN data bus.

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 instrument cluster transistor. Each time the ignition switch is turned to the ON position the engine temperature indicator is illuminated for about two seconds as a bulb test. The entire bulb test is a function of the PCM/ECM. The instrument cluster will turn ON the engine temperature indicator for the following reasons:

- Engine Temperature High or Critical Message - Each time the cluster receives an electronic engine temperature message from the PCM/ECM indicating the temperature is high [at or above about 127 °C (261 °F) for gasoline engines, or about 128 °C (262 °F) for diesel engines], the engine temperature indicator will be illuminated and a single chime tone is sounded. The indicator remains illuminated until the cluster receives a message from the PCM/ECM indicating that the temperature is below about 124 °C (255 °F), 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, then ON again by the appropriate messages from the PCM/ECM.

The PCM/ECM continually monitors the engine coolant temperature sensor to determine the engine operating temperature. The PCM/ECM then sends the proper 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 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.

ETC INDICATOR

The Electronic Throttle Control (ETC) indicator gives an indication to the vehicle operator when the ETC system, or a circuit or component of the system is inoperative. The ETC 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/ECM over the CAN data bus.

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 instrument cluster transistor. Each time the ignition switch is turned to the ON position the ETC indicator is illuminated for about three seconds, but no longer than 15 seconds. The entire bulb test is a function of the instrument cluster. The instrument cluster will turn ON the ETC indicator for the following reasons:

- ETC Indicator Lamp-On Message - Each time the cluster receives an electronic ETC indicator lamp-ON message from the PCM/ECM, the ETC indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the PCM/ECM message. The indicator remains illuminated solid or continues to flash for about 12 seconds or until the cluster receives a lamp-OFF message from the PCM/ECM, 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 indicator will be extinguished when the ignition switch is turned to the OFF position.

The PCM/ECM continually monitors the ETC system circuits and sensors to decide whether the system is in good operating condition. The PCM/ECM then sends the proper lamp-ON or lamp-OFF message to the instrument cluster. If the PCM/ECM sends a lamp-ON message after the bulb test, it indicates that the PCM/ECM has detected an ETC system malfunction or that the ETC system is ineffective. The PCM/ECM will store a DTC for any malfunction it detects.