5 COMPONENTS Description of components XF 95 series 2.4 FLUID LEVEL SENSORS The vehicle has a number of fluid level sensors, such as: - fluid level sensor for the cooling system - engine oil level sensor Coolant level sensor The coolant level sensor consists of two microswitches (reed switches), connected in parallel with two resistors. These microswitches are influenced by a magnetic field positioned outside the sensor. If the coolant level drops, the microswitches will be closed by a float fitted with a fixed magnet. The alarm switch detects that the coolant level is too low and short-circuits the resistor connected in parallel.
The daily inspection switch detects that the coolant needs to be topped up and short-circuits the resistor connected in parallel. The VIC uses the resistance value to detect the status of the microswitches. As a result the instrument display is activated by the VIC. 2 E501602 1 Note: The VIC will only send a message to the instrument display during the startup phase if the daily inspection switch is closed during the startup phase. 2 E501434 Engine oil level sensor The operation of the engine oil level sensor is based on a resistance measurement. When the contact is activated, a current is sent through the sensor from the VIC control unit for a specific period of time.
Applying this current briefly in this way ensures that the sensor is properly warmed up. When the level is being measured the resistance value is influenced by the quantity of oil in the sump. E501146 2-6 200303