Circuit Operation - Electronic Instrument Panel

Electronic Instrument Panel:

The Electronic Instrument Panel contains vacuum fluorescent displays for the speedometer, fuel gage, oil pressure gage, temperature gage and voltmeter. The Turn Lamps, Safety Belt Lamp, Malfunction Indicator lamp, BRAKE lamp and Headlamp High Beam Indicator use standard bulbs.

Ignition voltage to the cluster is supplied by the PNK/WHT (350) wire at C226. This circuit supplies voltage to the vacuum fluorescent displays and provides voltage to the BRAKE and Malfunction Indicator lamp and the Voltmeter.

The other circuits to the cluster provide the various signals necessary to operate the displays and indicators.

When the Ignition Switch is turned to RUN, all of the segments of the vacuum fluorescent displays are lit up for about two seconds, after which the displays then show current readings.

The vacuum fluorescent displays can be switched between English and Metric by the E/M switch. When the E/M switch is open, the displays are in English. When the E/M switch is closed, the displays are in Metric. This signal is sent to the cluster through the LT BLU (811) wire at C226. When the E/M switch is closed (Metric) the LT BLU (811) wire is connected to ground through the BLK (150) wire at the switch assembly.

Fuel Gage Display
The Fuel Gage Display shows the fuel level in the tank. This signal is supplied to the cluster through the PNK (30) wire at C226. With low fuel level in the tank, the sender resistance is low. With high fuel level in the tank, the sender resistance is high.

If the fuel level in the fuel tank drops below 4 gallons, a box around the gage ISO symbol flashes to indicate low fuel level.

Oil Pressure Gage Display
The Oil Pressure Gage Display shows the engine operating oil pressure. This signal is supplied to the cluster through the TAN (31) wire at C226. With low oil pressure, the sender resistance is low. With high oil pressure, the sender resistance is high.

If the engine oil pressure drops below 10 psi, a box around the oil pressure gage ISO symbol flashes to indicate low oil pressure.

Coolant Temperature Gage Display
The Coolant Temperature Gage Display shows the engine coolant temperature. This signal is sent to the cluster through the DK GRN (35) wire at C226. With low coolant temperature, the sender resistance is high. With high coolant temperature the sender resistance is low.

If the coolant temperature goes over 118°C (245°F), a box around the coolant temperature ISO gage flashes to indicate an engine overheat condition.

Voltmeter Display
The Voltmeter Display shows the battery voltage. The Voltmeter is connected to the PNK/WHT (350) wire at C226 and the BLK (150) wire at C226. If the generator output is high, low or 0 volts, a box around the Voltmeter ISO symbol flashes to indicate a problem with the charging system. This signal is sent to the cluster through the BRN (25) wire at C226.

Low Fuel Warning
When the fuel level in the tank is below 4 gallons, a box around the fuel gage ISO symbol will flash to indicate low fuel level. This should occur when the fuel level drops to the fourth segment from the bottom of the display.

NOTE: The ISO symbol will flash at the same full intensity the other cluster displays.

Low Oil Pressure Warning
If the engine oil pressure drops below 10 psi, a box around the Oil Pressure Gage ISO symbol will flash to indicate low oil pressure. This should occur when the third segment from the bottom of the display turns off.

NOTE: The ISO symbol will flash at full intensity regardless of the cluster setting.

High Coolant Temp Warning
If the coolant temperature goes above 118°C (245°F), a box around the Coolant Temperature Gage ISO symbol will flash to indicate a coolant overheat condition. This should occur when the second segment from the top of the display lights up.

NOTE: The ISO symbol will flash at full intensity regardless of the cluster setting.

Charge System Low Voltage Warning
If the charging system is producing high, low or no voltage, a box around the Voltmeter ISO symbol will flash to indicate a problem with the Charging System.

NOTE: The ISO symbol will flash at full intensity regardless of the cluster setting.

Cluster Switches
The odometer/trip odometer display is mounted on a separate board attached to the main display board. The odometer displays the total vehicle mileage up to 999,999 miles in the English mode. If the mileage exceeds this, the display flashes ERROR. In the Metric mode, the display will flash ERROR when it exceeds 999,999 kilometers. The English display will still show the normal display.

The display can be switched from total odometer to trip odometer by pushing the TRIP button. When the switch is open, the total mileage is displayed. When the TRIP switch is closed, the trip mileage is displayed. This signal is sent to the cluster through the LT GRN (226) wire at C226. When the TRIP switch is closed (trip mileage) the LT GRN (226) wire is connected to ground through the BLK (150) wire at the switch assembly.

The trip odometer can be reset to 0 by pushing the RESET button. This momentarily connects the LT GRN/BLK (376) wire at C226 to the BLK (150) wire at the switch assembly. The display must be in the TRIP mode to be reset.

The accumulated mileages of the two displays are stored in a non-volatile memory chip to prevent losing this data if the battery or cluster is disconnected.

If the cluster is replaced, the Odometer can be transferred to the new cluster.

The entire cluster is replaced as a unit. There are no dealer replaceable parts within the cluster. If there is a condition in the Digital Cluster, the whole cluster is removed and exchanged.