With Digital Cluster

The operation of an individual indicator is described along with its circuit. Refer to the schematic and text for the circuit that is stated below or above wires leading to that indicator.

Stop Engine Oil Indicator

Voltage is applied through the STOP ENGINE OIL Indicator to the Engine Oil Pressure Switch. The Engine Oil Pressure Switch is open with normal oil pressure. With low engine oil pressure, the switch closes and the indicator grounds through the switch.

Digital Cluster

The Instrument Cluster uses vacuum fluorescent displays to show vehicle speed, Total Odometer, the Trip Odometer, and Hi Beam Indicator. With the Ignition Switch in RUN, current flows from Fuse 7 to terminal J of the cluster. For 3 seconds all the displays light up to check all segments. After the segment check, the operating data is displayed.

Speedometer and Odometers

The cluster receives a speed signal from the Vehicle Speed Sensor through the Vehicle Speed Sensor Buffer. The frequency of the signal is related to the vehicle speed. The cluster contains a microprocessor which converts the speed signal into vehicle speed and mileage for the Speedometer and Odometer displays. The mileage figures are stored in the cluster's nonvolatile memory which retains information without the need for keep alive current. The driver can use the M/E switch to display speed and distance in English (mph and miles) or Metric (km/h and kilometers). The Speedometer reading has a maximum value in English and Metric. In English any speed over 85 mph will cause the display to flash 85. In Metric, any speed over 137 km/h will cause the display to flash 137.

Trip Set Switch

The Trip Set Switch is located in the Digital Cluster. When the switch is set, a grounding input is provided to the display boards which causes the trip odometer to reset.

Metric/English Switch

The M/E switch is located in the Digital Cluster. When the switch is pressed, a grounding input is provided to the display boards inside the cluster which causes an English/Metric mode change.

Display Illumination

The Body Computer Module (BCM) supplies 16 v to the vacuum fluorescent displays for illumination, and a signal to dim the displays. When the Headlights are off, the vacuum fluorescent displays are at maximum intensity. When the Headlights are on, the driver can adjust the intensity of the vacuum fluorescent displays by rotating the headlight knob. The Headlight knob controls the lighting rheostat which sends a variable voltage to the BCM. The BCM produces a dimming signal based on the voltage from the lighting rheostat.

Fuel Data Center

The Fuel Data Center (FDC) uses vacuum fluorescent displays to show fuel level and fuel related information. The Body Computer Module (BCM) provides the FDC with necessary voltages and data communication. All information for display is sent to the FDC from the BCM through the PPL wire. A clock signal, used to synchronize Input and Output data, is sent over the YEL wire. Five volt computer power is sent over the TAN wire. Sixteen volt vacuum fluorescent display power is sent over the ORN/BLK wire. A dimming voltage for the vacuum fluorescent display is sent over the GRY/WHT wire.

When the Ignition Switch is set to RUN, current from Fuse 7 flows to the FDC and a 3 second display segment check is made, after which, operating data is displayed.

Fuel Gage Sender

With the Ignition Switch in RUN, BULB, TEST, or START, voltage is available through Fuse 16 to the Fuel Gage Sender, which is a potentiometer provides an input voltage to the Body Computer Module (BCM) determined by the amount of fuel in the tank. If the tank is full, the voltage is at maximum as supplied by the Battery. If the tank is empty, the voltage will be near zero or ground. The variable voltage from the Fuel Gage Sender is sent to the BCM and converted for display by the Fuel Data Center.

Information Centers

The wiring schematic of the Information Center shows seven different Indicators. Circuit details showing how the Indicators turn on are shown on the schematic of each respective circuit, except for SERVICE AIR COND Indicator. This circuit is described below.

Voltage is applied to the SERVICE AIR COND Indicator with the Ignition Switch in RUN, BULB TEST, or START. The Refrigerant Low Side Temperature Sensor senses the temperature of the refrigerant in the system low pressure side. The sensor sends this signal to Body Computer Module. If the refrigerant charge has been depleted, system cooling will decrease. The Body Computer Module will detect this condition through the Refrigerant Low Side Temperature Sensor and will provide ground for the SERVICE AIR COND Indicator. The Indicator operates to wan the driver of the low refrigerant charge.