Part 4
OPERATION
SEATBELT INDICATOR
The seatbelt indicator gives an indication to the vehicle operator of the status of the driver side front seat belt. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming and a hard-wired input from the seatbelt switch on the driver side front seat belt retractor through the seat belt switch sense circuits.
The seatbelt indicator also includes a programmable enhanced seatbelt reminder or BELTMINDER feature that is enabled when the vehicle is shipped from the factory. This BELTMINDER feature can be disabled and enabled by using a specific programming event sequence Testing and Inspection , or by using a diagnostic scan tool.
The seatbelt 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 instrument cluster will turn ON the seatbelt indicator for the following reasons:
- Seatbelt Reminder Function - Each time the cluster receives a battery current input on the fused ignition switch output (run-start) circuit, the indicator will be illuminated as a seatbelt reminder for about six seconds, or until the ignition switch is turned to the OFF position, whichever occurs first. This reminder function will occur regardless of the status of the seatbelt switch inputs to the cluster.
- Front Seatbelt Not Buckled - Beltminder Active - Following the seatbelt reminder function, each time the cluster receives an open circuit message on the Can B Data Bus from the TIPM, (seatbelt switch open = seatbelt unbuckled) with the ignition switch in the START or ON positions, the indicator will be illuminated. In addition, if the front seat belt remains unbuckled about 4 seconds after the conclusion of the seatbelt reminder function, the seatbelt indicator will begin to cycle between flashing ON and OFF for 3 seconds, then lighting solid for 2 seconds. The seatbelt indicator will continue to cycle between flashing and solid illumination for 13 complete cycles, until the seat belt switch sense input to the cluster is a closed circuit to ground (seatbelt switch closed = seatbelt buckled), or until the ignition switch is turned to the OFF position, whichever occurs first.
- Front Seatbelt Not Buckled - Beltminder Inactive - Following the seatbelt reminder function, each time the cluster detects an open circuit on the seat belt switch sense circuit (seatbelt switch open = seatbelt unbuckled) with the ignition switch in the START or ON positions, the indicator will be illuminated. The seatbelt indicator remains illuminated until the seat belt indicator input to the cluster is a closed circuit to ground (seatbelt switch closed = seatbelt buckled), or until the ignition switch is turned to the OFF position, whichever occurs first.
The seatbelt switch is connected in series between ground and the seat belt switch sense circuit input to the instrument cluster. The seatbelt switch input to the EMIC circuitry may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information.
SECURITY SYSTEM INDICATOR
The security indicator gives an indication to the vehicle operator when the Vehicle Theft Security System (VTSS) is arming or is armed. On vehicles equipped with the Sentry Key Immobilizer System (SKIS), the security indicator also gives an indication to the vehicle operator of the status of the SKIS. This indicator is controlled by a transistor on the instrument cluster circuit board based upon cluster programming, and electronic security indicator request messages received by the cluster from the TIPM or the WIN, over the CAN data bus.
The security 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 instrument cluster transistor. Depending upon the programmed condition, the indicator can be illuminated solid, flashed at a slow rate (0.5 Hertz, 12.5 percent duty cycle), or flashed at a fast rate (1 Hertz, 50 percent duty cycle). Each time the ignition switch is turned to the ON position the security indicator illuminates for about two seconds as a bulb test. The entire bulb test is a function of the WIN. The instrument cluster will turn ON the security indicator for the following reasons:
- Security Indicator Lamp-On Message - During the 16 second VTSS arming function, the TIPM will request the cluster flash the security indicator ON and OFF repeatedly at a steady, fast rate to indicate that the VTSS is in the process of arming. Following successful VTSS arming, the TIPM will request the cluster flash the security indicator ON and OFF continuously at a slower rate to indicate that the VTSS is armed. The security indicator continues flashing at the slower rate until the VTSS is disarmed or triggered. If the VTSS has alarmed and rearmed, the TIPM will request the cluster flash the security indicator at a steady, slow rate for about 30 seconds after the VTSS is disarmed.
- SKIS Indicator Lamp-On Message - Each time the cluster receives an electronic SKIS indicator lamp-ON message from the WIN, the security indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the WIN message. The indicator remains illuminated solid or continues to flash until the cluster receives a lamp-OFF message from the WIN, or until the ignition switch is turned to the OFF position, whichever occurs first. For more information on the SKIS and the security indicator control parameters, Vehicle Theft Security System - Operation.
- Communication Error - If the cluster receives no lamp-ON or lamp-OFF messages from the TIPM or the WIN for 10 consecutive message cycles, the security indicator is illuminated by the instrument cluster. The indicator remains controlled and illuminated by the cluster until a valid lamp-ON or lamp-OFF message is received from the WIN.
The TIPM sends electronic security indicator request messages to control the security indicator whenever the ignition switch is in the OFF position and the VTSS is arming, armed, or alarming. Whenever the ignition switch is in the ON or START positions, the WIN performs a self-test to decide whether the SKIS is in good operating condition and whether a valid key is present in the ignition lock cylinder. The WIN then sends the proper lamp-ON or lamp-OFF message to the EMIC. If the cluster flashes the security indicator upon ignition ON, or turns ON the security indicator solid after the bulb test, it indicates that a SKIS malfunction has occurred or that the SKIS is inoperative.
TRACTION CONTROL INDICATOR
The traction control indicator gives an indication to the vehicle operator when the Electronic Stability Program (ESP)/Brake Assist System (BAS)/Traction Control System (TCS) has been activated. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and electronic messages received by the cluster from the CAB over the CAN data bus.
The traction control indicator 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 indicator will always be OFF when the ignition switch is in any position except ON or START. The indicator only illuminates when it is provided a path to ground by the instrument cluster circuitry. Each time the ignition switch is turned to the ON position the traction control indicator is illuminated for about four seconds as a bulb test. The entire bulb test is a function of the CAB. The instrument cluster will turn ON the traction control indicator for the following reasons:
- Traction Control Indicator Lamp-On Message - Each time the cluster receives an electronic traction control indicator lamp-ON message from the CAB indicating that the ESP/BAS/TCS has been activated, the traction control indicator will be illuminated. The indicator can be flashed ON and OFF, or illuminated solid, as dictated by the CAB message. The indicator remains illuminated solid or continues to flash 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 OFF switch to determine the proper outputs to the components of the ABS. The CAB then sends the proper lamp-ON or lamp-OFF message to the EMIC.
TRANSMISSION RANGE INDICATOR
The electronic gear selector indicator gives an indication to the vehicle operator of the transmission gear that has been selected with the automatic transmission gear selector lever. This indicator is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received from the Transmission Control Module (TCM), over the CAN data bus.
The gear selector indicator information is displayed by the odometer VFD unit soldered onto the instrument cluster electronic circuit board, and the VFD will not display the gear selector indicator information after the ignition switch is turned to the OFF position. Each time the cluster is disconnected from battery current for more than about five minutes, it must configure itself for the automatic transmission type that is in the vehicle once it is reconnected to battery current. The instrument cluster circuitry operates the gear selector indicator to provide the following features:
- Selected Gear Message - Each time the cluster receives an electronic selected gear message from the TCM, a box will be illuminated around the appropriate character in the gear selector indicator. The box will remain illuminated until the cluster receives a different selected gear message, or until the ignition switch is turned to the OFF position, whichever occurs first.
- Communication Error - If the cluster fails to receive a selected gear message from the PCM/ECM within three seconds, the instrument cluster circuitry will display all gear selector positions boxed (selected) until a valid selected gear message is received or until the ignition switch is turned to the OFF position, whichever occurs first.
The TCM continually monitors a hard-wired multiplex input from the Transmission Range Sensor (TRS), then sends the proper message to the EMIC.
WAIT-TO-START INDICATOR
The wait-to-start indicator gives an indication to the vehicle operator when the diesel engine is too cool for efficient and reliable engine starting, and the engine glow plugs are energized in their pre-heat operating mode. 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 ECM over the CAN data bus.
The wait-to-start 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 instrument cluster will turn ON the wait-to-start indicator for the following reasons:
- Wait-To-Start Indicator Lamp-On Message - Each time the cluster receives an electronic wait-to-start indicator lamp-ON message from the ECM indicating that the air temperature is too cool for efficient and reliable engine starting and the glow plugs are energized in their pre-heat mode, the wait-to-start indicator will be illuminated. The indicator remains illuminated until the cluster receives a lamp-OFF message from the ECM, until the ECM detects that the engine is running, or until the ignition switch is turned to the OFF position, whichever occurs first.
The ECM continually monitors the glow plug control circuits to determine when they are energized in their pre-heat operating mode. The ECM then sends the proper lamp-ON or lamp-OFF message to the EMIC.
WASHER FLUID INDICATOR
The washer fluid indicator gives an indication to the vehicle operator that the fluid level in the washer reservoir is low. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and electronic messages received by the cluster from the TIPM over the CAN data bus.
The washer fluid indicator function of the odometer or 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 ignition switch output (run-start) circuit. Therefore, the odometer or EVIC VFD washer fluid indication will always be OFF when the ignition switch is in any position except ON or START. The instrument cluster will turn ON the washer fluid indicator for the following reasons:
- Washer Fluid Indicator Lamp-On Message - Each time the cluster receives an electronic washer fluid indicator lamp-ON message from the TIPM indicating that a low washer condition has been detected for 60 consecutive seconds, the washer fluid indicator is illuminated and a single chime tone is sounded. The indicator remains illuminated until the cluster receives lamp-OFF messages for 60 consecutive seconds from the TIPM, 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 washer fluid indicator is cycled OFF and then ON again by the appropriate lamp-ON and lamp-OFF messages from the TIPM.
The TIPM continually monitors the washer fluid level switch in the washer reservoir to determine the level of the washer fluid. The TIPM then sends the proper lamp-ON or lamp-OFF message to the EMIC.
TURN SIGNAL INDICATORS
The turn signal indicators give an indication to the vehicle operator that the turn signal (left or right indicator flashing) or hazard warning (both left and right indicators flashing) have been selected and are operating. These indicators are controlled by transistors on the instrument cluster electronic circuit board based upon the cluster programming and electronic messages received from the TIPM over the CAN data bus.
Each turn signal 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, each LED can be illuminated regardless of the ignition switch position. The LED only illuminates when it is provided a path to ground by the instrument cluster transistor. The instrument cluster will turn ON the turn signal indicators for the following reasons:
- Turn Signal Indicator Lamp-On Message - The EMIC receives an electronic right or left turn signal-ON message from the multifunction switch over the over the LIN data bus. The EMIC in turn will transmit the request across the BUS to the TIPM and the appropriate turn signal indicator will be flashed ON and OFF. The TIPM will then send the appropriate electronic message to the cluster to control the flash rate of the turn signal indicators, as well as to control the click rate of an electromechanical relay soldered onto the cluster electronic circuit board that emulates the sound emitted by a conventional turn signal flasher. The turn signal indicators continue to flash ON and OFF 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.
- Hazard Warning Indicator Lamp-On Message - The EMIC receives an electronic hazard warning-ON message from the multifunction switch across the LIN data bus. The EMIC will transmit this request to the TIPM and the TIPM then sends the appropriate electronic messages to the cluster to control the flash rate of the right and left turn signal indicators, as well as to control the click rate of an electromechanical relay soldered onto the cluster electronic circuit board that emulates the sound emitted by a conventional hazard warning flasher. The turn signal indicators continue to flash ON and OFF until the cluster receives a hazard warning-OFF message from the TIPM.
- Lamp Out Mode - If the TIPM detects an ineffective turn signal lamp or circuit, it increases the flash rate for the remaining operative turn signals and sends an electronic message to the instrument cluster. The instrument cluster then increases the flash rate of the turn signal indicators and the click rate of the electromechanical relay to provide an indication of the problem to the vehicle operator.
The EMIC continually monitors the electronic messages from the TIPM to determine the proper turn signal and hazard warning indicator operation.