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Coolant temperature

Coolant temperature

The coolant temperature gauge gives the driver information regarding the engine coolant temperature.

The main instrument unit receives information from the engine coolant temperature sensor located in the left-hand end of the cylinder head where it is in contact with the engine's coolant. This sensor is of NTC type. The main instrument unit measures the coolant temperature by supplying the sensor with 5 V from pin 15 (K22) via an integrated 680 Ohm resistor. The sensor is grounded via main instrument unit pin 7 (K22). The voltage across the resistor in the main instrument unit is proportional to the temperature of the coolant. Information on the current coolant temperature is sent out on a bus from the main instrument unit. The information is thus available to DICE.

DICE uses the coolant temperature to control operation of the radiator fan.

The coolant temperature gauge scale is divided into 5 fixed points. The main instrument unit is programmed to guide the gauge needle to the fixed points at the specified temperatures in order to give stable indication at normal coolant temperatures.

The following fixed points are programmed in the main instrument unit (factory setting):



Gauge needle:

Coolant temperature

- in the "blue" range

30°C (fixed value)

- out of "blue" range

50°C

- in "horizontal" position

80°C

- out of "horizontal" position

115°C

- in "red" range

129°C

- out of "red" range

133°C (fixed value)



Diagnosis

For diagnosis see group 3, “Main instrument unit MIU“.