Systems and methods for electrically heated exhaust catalyst diagnostics
AssigneeFord Global Technologies, LLC
InventorAed Dudar
Life of this patent
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Abstract
Methods and systems are provided for diagnosing an electric heater configured to increase a temperature of an exhaust catalyst positioned in an exhaust system of an engine. In one example, a method comprises diagnosing the electric heater by activating the electric heater, routing air flow from the exhaust system to an intake of the engine, and indicating the electric heater is degraded based on a test temperature in the intake being below a threshold temperature. In this way, the electric heater may be diagnosed without inclusion of costly sensors in the exhaust catalyst, and where such diagnosis conducted periodically may reduce release of undesired emissions to atmosphere.
Claims20
A method comprising:
- diagnosing an electric heater configured to increase a temperature of an exhaust catalyst positioned in an exhaust system of an engine of a vehicle by activating the electric heater, routing air flow from the exhaust system to an intake of the engine, and indicating the electric heater is degraded based on a test temperature in the intake being below a threshold temperature.
A method comprising:
- diagnosing an electric heater coupled to an exhaust catalyst positioned in an exhaust system of an engine of a vehicle via obtaining a baseline temperature in an intake of the engine under conditions where an air flow is routed from the exhaust system to the intake without activation of the electric heater and then subsequently obtaining a test temperature of the intake of the engine under conditions where the air flow is routed from the exhaust system to the intake with activation of the electric heater, where diagnosing the electric heater includes indicating the electric heater is functioning as desired in response to the test temperature being greater than a threshold temperature.
A system for a hybrid vehicle, comprising:
- an engine including an intake and an exhaust system;
- an exhaust catalyst positioned in the exhaust system;
- an electric heater configured to heat the exhaust catalyst;
- an intake air temperature sensor positioned in the intake;
- a throttle positioned in the intake;
- and
- a controller storing instructions in non-transitory memory, that when executed, cause the controller to:
- command fully open the throttle;
- obtain a baseline intake air temperature via the intake air temperature sensor while routing a first air flow from the exhaust system to the intake without activating the electric heater;
- obtain a test intake air temperature while routing a second air flow from the exhaust system to the intake with the electric heater activated;
- and
- indicate the electric heater is degraded in response to the test intake air temperature being below a threshold intake air temperature, the threshold intake air temperature set a predetermined amount greater than the baseline intake temperature.
Dependencies are inferred from the claim text.