Part 4

OPERATION

TRACTION CONTROL INDICATOR





The traction control indicator gives an indication to the vehicle operator when the electronic Traction Control System (TCS) has been activated. This indicator is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Controller Antilock Brake (CAB) over the Controller Area Network (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 switched to ground by the instrument cluster circuitry. The instrument cluster will turn on the traction control indicator for the following reasons:

- Bulb Test - 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.
- Traction Control Lamp-On Message - Each time the cluster receives a traction control lamp-on message from the CAB indicating that the TCS has been activated, the traction control indicator will be illuminated. The indicator remains illuminated until the cluster receives a traction control lamp-off message from the CAB, or until the ignition switch is turned to the Off position, whichever occurs first.
- Actuator Test - Each time the cluster is put through the actuator test, the traction control indicator will be turned on, then off again during the bulb check portion of the test to confirm the functionality of the LED and the cluster control circuitry.

The CAB continually monitors the traction control switch to determine the proper outputs to the components of the Antilock Brake System (ABS). The CAB then sends the proper traction control lamp-on and lamp-off messages to the instrument cluster. For further diagnosis of the traction control indicator or the instrument cluster circuitry that controls the indicator, Testing and Inspection. The Traction Control indicator is serviced with the instrument cluster.

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, a hard wired multiplex input received by the cluster from the turn signal and hazard warning switch circuitry of the multi-function switch on the turn/hazard switch mux circuit, and electronic messages received from the Totally Integrated Power Module (TIPM) over the Controller Area Network (CAN) data bus.

Each turn signal indicator Light Emitting Diode (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-On Input - The Steering Control Module (SCM) sends a Data Bus message to the TIPM to turn on the turn signals. The TIPM also sends out a message to the CCN to illuminate the appropriate electronic turn signal switch indicator. The TIPM controls the output and the flash rate for either the right or left turn signal lamps and sends this message to the CCN. The CCN will then control the illumination and flash rate of the right or left turn signal indicators, as well as to control the click rate of an electromechanical relay soldered onto the CCN electronic circuit board that emulates the sound emitted by a conventional turn signal flasher. The turn signals and the turn signal indicators continue to flash on and off until the cluster receives a turn signal-off input from the multi-function switch, or until the ignition switch is turned to the Off position, whichever occurs first.
- Hazard Warning-On Input - The turn signal flashers are also controlled by the TIPM. The SCM sends a Data Bus message to the TIPM and the TIPM responds to these messages by controlling a battery voltage output and the flash rate for each of the right and left turn signal lamps. The TIPM also sends the appropriate electronic messages back to the CCN to control the illumination and 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 CCN electronic circuit board that emulates the sound emitted by a conventional hazard warning flasher. The turn signals and the turn signal indicators continue to flash on and off until the cluster receives a hazard warning-off input from the multi-function switch.
- Lamp Out Mode - The instrument cluster also sends electronic turn signal on and off messages to the TIPM over the CAN data bus, and the TIPM flashes the appropriate exterior turn signal lamps. If the TIPM detects an inoperative turn signal lamp or circuit, it increases the flash rate for the remaining operative turn signals and sends an electronic message back to the instrument cluster. The instrument cluster then increases the flash rate of the turn signal indicator(s) and the clicking rate of the electromechanical relay to provide an indication of the problem to the vehicle operator.
- Actuator Test - Each time the cluster is put through the actuator test, the turn signal indicators will be turned on, then off again during the bulb check portion of the test to confirm the functionality of each LED and the cluster control circuitry.

The instrument cluster continually monitors the multi-function switch and electronic messages from the TIPM to determine the proper turn signal and hazard warning system control. For further diagnosis of the turn signal indicators or the instrument cluster circuitry that controls the indicators, Testing and Inspection. The Turn Signal indicators are serviced with the instrument cluster.

CLUSTER ILLUMINATION

The CCN has a single electro-luminescent lamp that provides cluster back lighting whenever the exterior lighting is turned On. The illumination intensity of this lamp is adjusted when the interior lighting thumbwheel on the headlamp switch is rotated (down to dim, up to brighten). The CCN monitors a resistor multiplexed input from the headlamp switch on a dimmer input circuit. In response to that input, the CCN will vary the PWM voltage from 5.6 rms to 13.5 volts rms.it receives on a hard wired panel lamps dimmer switch signal circuit into a 12-volt Pulse Width Modulated (PWM) output.

The CCN uses this PWM output to control the illumination intensity of the electro-luminescent cluster illumination lamp and the VFD units on the CCN circuit board, then provides a synchronized PWM output on various hard wired fused panel lamps dimmer switch signal circuits to control and synchronize the illumination intensity of other incandescent illumination lamps in the vehicle. The CCN also transmits electronic dimming level messages over the CAN data bus to other electronic modules in the vehicle to control and synchronize the illumination intensity of their VFD units to that of the CCN VFD units.

In addition, the thumbwheel on the headlamp switch has a Parade Mode position to provide a parade or funeral mode. The CCN monitors the request for this mode from the headlamp switch, then transmits an electronic dimming level message to illuminate all VFD units in the vehicle at full (daytime) intensity for easier visibility when driving in daylight with the exterior lighting turned On.

ELECTRONIC VEHICLE INFORMATION CENTER

The following Modes allow the driver to access and display the driver- interactive features:

TRIP MODE

Provides a choice of units displayed in English or metric. The following information can be displayed at the top of the screen: Average MPG, distance to empty (DTE), Trip A and Trip B odometers, and elapsed time. The odometer is displayed at the bottom of the screen. If warnings exist, they will replace the odometer in the display. The driver can scroll to view multiple warnings.

COMPASS, TEMPERATURE AND AUDIO MODE

Compass heading and outside temperature are displayed at the top of the screen. On the lower half of the screen the audio mode is displayed along with the odometer.

TELEPHONE MODE

Provides the following information and features for the optional hands-free communications system:

- Phone status: idle, voice mail, roaming, battery strength and signal strength in increments of 20 percent.
- Call status: Incoming call, connecting, connected, air time in minutes and seconds, call ended, busy, call failed, roaming and no phone connection.
- Caller ID phone number display.

NAVIGATION MODE

Displays Turn-by-Turn directions that appear in the display as the vehicle approaches a designated turn within a programmed route.

PERSONAL SETTINGS MODE

Allows the driver to set and recall features when the transmission is in Park.

SYSTEM STATUS MODE

Displays warnings and user interaction messages. Initial warnings will be displayed full-screen for three seconds, then override the odometer and show text warnings on the bottom line of the display. Critical text warnings will be displayed until the failure is corrected. Non-critical text warnings will be displayed for 60 seconds. The driver can scroll to view multiple messages. A single chime sounds for all warnings.

For a more detailed operation of the EVIC Electronic Vehicle Information Center - Operation.