Ambient temperature sensor rationality check
AssigneeFord Global Technologies, LLC
InventorAed M. Dudar
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for diagnosing temperature sensors of a vehicle. In one example, a method may include, at a duration after an engine-off event, determining that an intake air temperature measured by an intake air temperature sensor of the vehicle is less than an ambient air temperature measured by an ambient air temperature sensor of the vehicle. In response to the determining, the method may include flowing air from a catalyst across the intake air temperature sensor; and indicating the intake air temperature sensor is functional responsive to the intake air temperature converging to the ambient air temperature during the flowing.
Claims18
A method, comprising:
- at a duration after an engine-off event, determining that an intake air temperature (IAT) measured by an IAT sensor of a vehicle is less than an ambient air temperature (AAT) measured by an AAT sensor of the vehicle;
- in response to the determining, flowing air from a catalyst across the IAT sensor;
- and
- indicating the IAT sensor is functional responsive to the IAT converging to the AAT during the flowing.
A hybrid vehicle system, comprising:
- a vehicle including an engine, the engine coupled to an electric machine;
- an electric motor coupled to a battery and capable of propelling the vehicle;
- an intake air temperature (IAT) sensor positioned in an intake manifold of the engine;
- an ambient air temperature (AAT) sensor positioned on external component of the vehicle;
- a catalyst positioned in an exhaust passage downstream of the engine;
- an exhaust gas temperature (EGT) sensor positioned proximate the catalyst;
- and
- a controller storing computer readable instructions in non-transitory memory executable to:
- at a duration after an engine-off event and responsive to an intake air temperature measured by the IAT sensor being less than an ambient air temperature measured by the AAT sensor and further responsive to a temperature of the catalyst measured by the EGT sensor being equal to or greater than the ambient air temperature, activating the electric machine to rotate the engine in a reverse direction to flow air from the catalyst across the IAT sensor;
- and
- upon activating the electric machine, indicate the intake air temperature sensor is functional responsive to the intake air temperature converging to the ambient air temperature.
A method, comprising:
- waking a control module of a vehicle after an engine soak of a predetermined duration;
- upon waking the control module, performing, with the control module, a rationality test of an intake air temperature sensor, an ambient air temperature sensor, and an engine temperature sensor of the vehicle, the rationality test including a pre-check confirming the ambient air temperature sensor is functional;
- responsive to the rationality test indicating an ambient air temperature measured by the ambient air temperature sensor is greater than an intake air temperature measured by the intake air temperature sensor, determining if divergence between the intake air temperature sensor and the ambient air temperature sensor is due to solar heating of the ambient air temperature sensor or due to a degraded intake air temperature sensor by rotating an engine of the vehicle in reverse to flow heated air from a catalyst across the intake air temperature sensor;
- upon rotating the engine in reverse and responsive to the intake air temperature measured by the intake air temperature sensor converging with the ambient air temperature measured by the ambient air temperature sensor, indicating the divergence is due to solar heating;
- and
- upon rotating the engine in reverse and responsive to the intake air temperature measured by the intake air temperature sensor not converging with the ambient air temperature measured by the ambient air temperature sensor, indicating the divergence is due to the intake air temperature sensor being degraded.
Dependencies are inferred from the claim text.