Humidity sensor diagnostics
AssigneeFord Global Technologies, LLC
InventorsRoss Dykstra Pursifull, Imad Hassan Makki, Timothy Joseph Clark, Michael James Uhrich, Pankaj Kumar
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Abstract
Embodiments for diagnosing a humidity sensor are provided. One example method comprises, responsive to a humidity sensor test cycle, pumping air conditioning and windshield washer gas flows past a humidity sensor, and indicating humidity sensor degradation based on a response of the humidity sensor to the air conditioning and windshield washer gas flows. In this way, degradation of the humidity sensor may be indicated if the humidity sensed by the humidity sensor does not change responsive to the humidity sensor test cycle being initiated.
Claims12
A method, comprising:
- responsive to a humidity sensor test cycle,
- pumping air conditioning gas flow into an engine air intake system and pumping windshield washer gas flow into the engine air intake system, where the air conditioning and windshield washer gas flows flow past a humidity sensor disposed in the engine air intake system;
- and
- indicating humidity sensor degradation based on a response of the humidity sensor to the air conditioning and windshield washer gas flows.
A method, comprising:
- during a first condition, measuring humidity of a first air flow in an engine air intake system by directing the first air flow to a humidity sensor in the engine air intake system;
- during a second condition, measuring humidity of a second air flow in an air conditioning system by pumping the second air flow to the humidity sensor in the engine air intake system;
- wherein the second condition comprises air from downstream of an air conditioning system evaporator being directed to the humidity sensor;
- if the humidity of the first air flow differs from the humidity of the second air flow by less than a threshold amount, indicating humidity sensor degradation;
- during a third condition, measuring humidity of a third air flow pumped from an ullage space of a chamber housing windshield washer fluid to the humidity sensor,
- and if the humidity of the first air flow differs from the humidity of the third air flow by less than a threshold amount, indicating humidity sensor degradation.
Dependencies are inferred from the claim text.