Base Cluster

CIRCUIT OPERATION
See the circuit referred to for the complete operation of an indicator and other components that work with it. Only the indicators that do not appear in other schematics are described in this section.

FUEL GAGE
The Fuel Gage is a vacuum fluorescent bar display which is controlled by a microprocessor within the cluster. The cluster reads an analog resistance signal from the Fuel Gage Sender and converts this signal into a digital signal used by the bar graph display. The Fuel Gage Sender is a variable resistor. Its resistance is approximately 1 ohm with an empty tank.

SPEEDOMETER/ODOMETER
The Speedometer and Odometer are digital displays controlled by a microprocessor within the Instrument Cluster. The Cluster receives a vehicle speed signal from the ECM in the form of voltage pulses. The frequency of these pulses is 4000 pulses per mile. The ECM receives its speed signal from the Vehicle Speed Sensor.

"COOLANT TEMPERATURE" INDICATOR
(V6 VIN L)
The "COOLANT TEMPERATURE" Indicator comes on to warn the driver of high coolant temperature. Battery voltage is applied to the "COOLANT TEMPERATURE" Indicator with the Ignition Switch in "RUN," "BULB TEST" or "START." The "COOLANT TEMPERATURE" Indicator is grounded by the ECM with the Ignition Switch in "RUN" as a bulb check. When the ECM senses high coolant temperature, it grounds the indicator. The ECM senses coolant temperature through the Coolant Temperature Sensor.

"COOLANT TEMPERATURE" INDICATOR
(V6 VIN T)
The "COOLANT TEMPERATURE" Indicator warns the driver of a high coolant temperature. With the Ignition Switch in "RUN," "BULB TEST" or "START," voltage from the INDIC Fuse is applied to the "COOLANT TEMPERATURE" Indicator. The bulb is grounded through the Coolant Temperature Switch. The Switch closes when the coolant temperature exceeds 260° F (127° C). The bulb lights.



"OIL" PRESSURE INDICATOR
The "OIL" Pressure Indicator comes on to warn the driver when the engine oil pressure is low. Battery voltage is applied to one side of the bulb. A ground path is provided by the Fuel Pump/Oil Pressure Switch. It closes when the oil pressure is below 26 kPa (4 psi) and the Indicator bulb lights. After the Engine starts and normal oil pressure builds up, the Fuel Pump/Oil Pressure Switch opens. The "OIL" Pressure Indicator goes out.

"LOW COOLANT" INDICATOR
The "LOW COOLANT" indicator receives battery voltage with the ignition Switch in "RUN," "BULB TEST" or "START." The indicator is grounded by the Coolant Level Switch with the coolant level in the Coolant Reservoir below a minimum recommended level.