Heating and ventilation (Control panel): Description and operation

Control panel

The controls for heating and ventilation are installed on a control panel in the centre of the fascia, below the radio. Three rotary knobs control the LH and RH outlet temperatures and distribution. A slider switch controls blower speed. A latching pushswitch controls the selection of fresh/recirculated air; an amber LED in the switch illuminates when recirculated air is selected.

Graphics on the panel and the controls indicate the function and operating positions of the controls.

Outlet vent

The outlet vent promotes the free flow of heating and ventilation air through the cabin. The outlet vent is installed in the RH rear quarter body panel and vents cabin air into the sheltered area between the rear quarter body panel and the outer body side panel. The vent consists of a grille covered by soft rubber flaps and is effectively a non-return valve. The flap opens and closes automatically depending on the differential between cabin and outside air pressures.

FBH system (diesel models only)

The FBH system is an auxiliary heating system that compensates for the relatively low coolant temperatures inherent in the diesel engine. At low ambient temperatures, the FBH system heats the coolant supply to the heater assembly, and maintains it within the temperature range required for good in-car heating performance. Operation is fully automatic, with no intervention required by the driver.

The system consists of an air temperature sensor, a FBH fuel pump and a FBH unit. Fuel for the FBH system is taken from the fuel tank, through a line attached to the fuel tank's fuel pump, and supplied via the FBH fuel pump to the FBH unit. The connection on the fuel tank's fuel pump incorporates a tube which extends down into the tank. At the FBH unit connection, the fuel line incorporates a self-sealing, quick disconnect coupling. In the FBH unit, the fuel delivered by the FBH fuel pump is burned and the resultant heat output is used to heat the coolant. An ECU integrated into the FBH unit controls the operation of the system at one of two heat output levels, 2.5 kW at part load and 5 kW at full load

Ambient temperature sensor The ambient temperature sensor controls a power supply from the alternator to the FBH unit. The sensor is installed on the RH support strut of the bonnet closing panel and contains a temperature sensitive switch that is closed at temperatures below 5 °C (41 °F) and open at temperatures of 5 °C (41

°F) and above.