Method for diagnosing air intake throttle actuators for internal combustion engines

• US 7,680,581 B2
• Filed: 12/19/2007
• Issued: 03/16/2010
• Est. Priority Date: 12/19/2007
• Status: Expired due to Fees

• Current Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Original Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Inventors: Zurawski, Mark Allen
• Primary Examiner(s): Gimie, Mahmoud
• Application Number:
  US11/959,601
• Publication Number:
  US 20090164092A1
• Time in Patent Office: 818 Days
• Field of Search: 123/399, 123/396, 123/403, 123/361, 701/103, 701/115
• US Class Current: 701/103
• CPC Class Codes: F02D 2011/102 at least one throttle being moved only by an electric actuator
• CPC Class Codes: F02D 2041/1431 the system including an input-output delay
• CPC Class Codes: F02D 2200/0404 Throttle position
• CPC Class Codes: F02D 2250/16 End position calibration, i.e. calculation or measurement of actuator end positions, e.g. for throttle or its driving actuator
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method for diagnosing an air intake throttle with a spring activated throttle actuator, on an electronic controlled internal combustion engine system including an electronic control unit (ECU) with memory, a battery electrically connected to said engine and an ignition switch for connecting said battery to said engine and supplying current, comprising engaging the ignition switch to close a circuit between said battery and said engine; applying a first predetermined voltage to an air intake throttle plate actuator and determining a first period of throttle response time elapsed from a full open throttle position to a full close throttle position for a first throttle velocity; discontinuing application of said first predetermined voltage to said air intake throttle actuator and determining a second period of throttle response time elapsed from a full close throttle position to a full open throttle position for a second throttle velocity; applying a second voltage to said air intake throttle plate actuator and determining a third period of throttle response time elapsed from a full open throttle position to a full close throttle position for a third throttle velocity; and determining a fourth period of throttle response time elapsed from a full close throttle position to a full open throttle position with no voltage applied to the throttle plate actuator for a fourth throttle velocity.

Claims

1. A method for diagnosing an air intake throttle with a spring and motor activated throttle actuator, on an electronic controlled internal combustion engine system including an electronic control unit (ECU) with memory, a battery electrically connected to said engine and an ignition switch for connecting said battery to said engine and supplying current, comprising:

engaging the ignition switch to close a circuit between said battery and said engine;

applying a first predetermined voltage to an air intake throttle plate actuator and determining a first period of throttle response time elapsed from a full open throttle position to a full close throttle position for a first throttle velocity;

discontinuing application of said first predetermined voltage to said air intake throttle actuator and determining a second period of throttle response time elapsed from a full close throttle position to a full open throttle position for a second throttle velocity;

applying a second voltage to said air intake throttle plate actuator and determining a third period of throttle response time elapsed from a full open throttle position to a full close throttle position for a third throttle velocity; and

determining a fourth period of throttle response time elapsed from a full close throttle position to a full open throttle position with no voltage applied to the throttle plate actuator for a fourth throttle velocity.

2. The method of claim 1, wherein said first predetermined period of time is approximately 200 milliseconds;

said first predetermined voltage is approximately 2 amps;

said second predetermined time is approximately 80 milliseconds;

said third predetermined period of time is approximately 320 milliseconds, said second predetermined voltage is approximately 1.75 amps and said fourth predetermined period of time is approximately 350 milliseconds.

3. The method of claim 1, further including logging a plausibility fault in the ECU memory if the throttle response time exceeds at least three predetermined time checks.

4. The method of claim 1, further including logging a fault in the ECU memory if the velocity of the throttle falls above or below a predetermined calibrated threshold while moving between positions.

5. The method of claim 1 wherein the current is pulsed at ever increasing current with sufficient delay between each increase in current as to not exceed a maximum average current for a given time if the throttle does not attain full open or full closed throttle position.

6. The method of claim 1, further including logging a plausibility fault in ECU memory if the current necessary to hold the throttle plate in a desired position exceeds more than some calibratable percentage of spring force of the spring activated throttle plate actuator.

7. The method of claim 5, wherein the ramp rate and delay between successive current pulses are calibratable.