Analogue Instruments

ANALOG INSTRUMENTS

The analog instruments located in the instrument cluster are as follows:
^ Speedometer
^ Tachometer
^ Fuel level gage
^ Engine coolant temperature gage.

The speedometer, tachometer, fuel gauge and engine temperature gauge are each driven by an electronic stepper motor. The characteristics of this type of motor produce damping of the pointer needle. All of the gages return to their respective zero positions when the ignition is switched off.

Speedometer
The speedometer is driven by square wave signals derived from the wheel speed sensors and the ABS module. The wheel speeds are measured by the wheel speed sensors reading the rotational speed of the wheels from toothed targets on the hubs. The wheel speeds are passed from the sensors to the ABS module in the form of pulsed signals. The ABS module converts these signals into a speed output on the high speed CAN to the instrument cluster.

Three versions of the speedometer display are used. The three versions show the speed in kilometers per hour, the speed in miles per hour as the main display and kilometers per hour as a secondary display and Canadian variants show the kilometers per hour as the main display and miles per hours as the secondary display.

Tachometer
The tachometer is driven by an engine speed signal transmitted on the high speed CAN from the ECM. The signal is derived from the Crankshaft Position (CKP) sensor. The signal is received by the instrument cluster microprocessor and the output from the microprocessor drives the tachometer. Two versions of the tachometer are used for petrol and diesel engine variants. The petrol engine variants use a display which has a maximum engine speed reading of 8000 rev/min. The diesel engine variants use a display which has a maximum engine speed reading of 6000 rev/min.

Fuel Level Gage
Fuel Level Gage The fuel level gage displays the fuel tank contents. When the ignition is off, the pointer returns to the empty position.

The instrument pack is connected to two tank level sensors. One sensor is located at the front of the fuel tank and the other is located at the rear. Each sensor uses a float operated MAgnetic Passive Position Sensor (MAPPS) for measuring the fuel tank contents.

Each sensor is supplied with a reference current from the instrument cluster. The instrument cluster measures the returned output from each sensor which is proportional to the amount of fuel in the tank and the position of the float arm. The inclination of the vehicle, derived from a CAN message from the Electronic Park Brake (EPB) module, is also used to calculate the fuel tank contents. The instrument cluster uses the fuel level sensor signals and the EPB module inclination signals to accurately calculate the volume of fuel in the tank and display this on the fuel level gage. The instrument cluster monitors the signals and updates the fuel level gage pointer position at approximately 20 second intervals. This prevents the pointer moving continually due to fuel movement in the tank due to cornering or braking. When the ignition is off, the pointer needle returns to the empty position.

A warning lamp is incorporated into the fuel level gage and illuminates when the fuel tank volume is at or below 10 liters (2.19 Gallons) on petrol models and 18 liters (3.96 Gallons) on diesel models. This is accompanied by a chime from the instrument cluster to alert the driver to the low fuel condition. On vehicles with a high line instrument cluster the low fuel level is also displayed in the message center.

The fuel tank contents is converted into a CAN signal by the instrument cluster and transmitted on the CAN. This is used by the fuel fired booster heater to suspend operation on diesel variants.

The following table shows the fuel tank fuel quantity and the respective pointer positions.





Engine Coolant Temperature Gage
The engine coolant temperature gage displays the engine coolant temperature to the driver. When the ignition is off the pointer needle returns to the cold position.

The engine coolant temperature sensor is connected to the ECM which monitors the sensor signals and converts the signals into a value for the engine coolant temperature. This information is transmitted on the high speed CAN for use by the instrument cluster and other systems.

The engine coolant temperature gage is the same on all pack variants. The gage has a blue segment for low temperatures and a red segment for excessively high temperatures. For normal operating temperatures the gage needle pointer is positioned centrally in the gage display zone. The needle pointer position translates to the following approximate temperatures.

Engine Coolant Temperature �C (�F) Ignition off Park position
Ignition off Park position
40 (104) Cold (Blue segment)
75 - 115 (167 - 239) Normal
120 (248) Start of hot (Red segment)
125 (257) End of hot