Fuel level sensor diagnosis device
AssigneeDenso Corporation
InventorBin WANG
Life of this patent
Estimating the term…
Abstract
A fuel level sensor detects the level of fuel in a fuel tank. A level signal detected by a float does not change in a full dead zone and an empty dead zone. During normal fuel consumption, the level signal changes according to the consumption amount. Thus when an electronic control unit, or ECU, detects that the fuel level sensor is operating normally, the ECU resets a fuel consumption amount. However, when a small quantity of fuel is supplied, the fuel consumption amount is not reset, and a measurement error may occur during failure detection. Accordingly, the ECU corrects a failure threshold value to avoid misdiagnosing a failure.
Claims6
A fuel level sensor diagnosis device for receiving a fuel level signal from a fuel level sensor that detects a remaining quantity of fuel in a fuel tank and for determining a failure in the fuel level sensor, comprising:
- a fuel consumption integrator that integrates a fuel consumption amount signal representing a consumed amount of fuel of the fuel tank;
- a determination unit that determines a failure in the fuel level sensor when a total fuel consumption amount from the fuel, consumption integrator exceeds a failure threshold value;
- an integrated value reset unit that resets the total fuel consumption amount when a change amount of the fuel level signal exceeds a predetermined reset threshold value;
- and
- a correction unit that, if the change amount of the fuel level signal does not exceed the reset threshold value when the fuel tank is supplied with fuel, determines a small quantity refueling and corrects the failure threshold value of the determination unit.
Dependencies are inferred from the claim text.