Method to control and diagnose an exhaust gas heat exchanger
AssigneeFord Global Technologies, LLC
InventorsAngel Fernando Porras, Douglas Raymond Martin
Life of this patent
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Abstract
A method for controlling a vehicle having an engine with an exhaust heat recovery system, includes generating a signal to control exhaust gas flow through an exhaust gas heat exchanger, and generating a diagnostic code based on the signal and a rate of change of coolant temperature. A vehicle has an engine and an exhaust heat recovery system with an exhaust gas heat exchanger and a temperature sensor. A controller for the vehicle is configured to (i) generate a signal to control exhaust gas flow through the exhaust gas heat exchanger, and (ii) generate a diagnostic code based on the signal and a rate of change of coolant temperature.
Claims11
A vehicle comprising:
- an engine;
- an exhaust heat recovery system for the engine, the system having an exhaust gas heat exchanger, a first coolant temperature sensor positioned upstream of the exhaust gas heat exchanger, and a second coolant temperature sensor positioned downstream of the exhaust gas heat exchanger;
- and
- a controller configured to (i) generate a signal to control exhaust gas flow through the exhaust gas heat exchanger, and (ii) generate a diagnostic code based on the signal, a rate of change of coolant temperature, and another rate of change of coolant temperature, wherein the rate is determined using a first signal received from the first sensor, and a second signal received from the first sensor after a predetermined time period, and wherein the another rate is determined using a third signal received from the second sensor, and a fourth signal received from the second sensor after the predetermined time period.
A computer readable medium having stored data representing instructions executable by a controller to control a vehicle, comprising:
- instructions for generating a signal to control exhaust gas flow through an exhaust gas heat exchanger;
- and
- instructions for generating a diagnostic code based on the signal, a rate of change of coolant temperature based on a first coolant temperature measured by a first coolant temperature sensor and a second coolant temperature measured by the first coolant temperature sensor after a predetermined time period, and another rate of change of coolant temperature based on a third coolant temperature measured by a second coolant temperature sensor and a fourth coolant temperature measured by a second coolant temperature sensor after the predetermined time period;
- wherein the first coolant temperature sensor is positioned upstream of the exhaust gas heat exchanger, and the second coolant temperature sensor is positioned downstream of the exhaust gas heat exchanger.
Dependencies are inferred from the claim text.