Fuel gauge
Fuel gauge |
The fuel gauge informs the driver how much fuel is left in the tank. It consists of a fuel gauge in the main instrument unit and a level sensor in the tank.
The level sensor has a variable resistance which value corresponds to the level of the sensor float in the tank, and the resistance increases with a higher fuel level. The resistance is 501.5 Ohm when the tank is empty and 4256.5 Ohm at full tank.
The sensor is connected to pin 9 (K12) of the main instrument unit control module where it is supplied with B+ and grounded through pin 8 (K12).
The control module detects the sensor's resistance and controls the current to the fuel gauge so that the position of the meter needle corresponds to the resistance of the sensor.
To give a more accurate reading at low fuel levels, the main instrument unit's control module switches to measuring fuel consumption when the fuel level in the tank is below 10 litres.
The main instrument unit control module sends information on the fuel level to the buses.
Fuel reserve indicator lamp |
With about 10 litres of fuel remaining in the tank, the lamp lights up to indicate low fuel level. The lamp is supplied with current from the main instrument unit and grounded by the main instrument unit's control module when it is to be lit.
The main instrument unit lights this lamp for three seconds when the ignition is switched on.
Fuel consumption |
Trionic sends out fuel consumption information on the bus.
The main instrument unit control module uses the information to control the fuel gauge (under 10 litres).