Control of automatic transmission shift by wire range selection

• US 9,200,707 B2
• Filed: 09/27/2010
• Issued: 12/01/2015
• Est. Priority Date: 09/27/2010
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Spaulding, Todd C., Deurloo, Brian J., Zyskowski, Mark E., Danks, Christopher L., Fyie, Matthew L., Poon, Charles C., Goodwin, William R., Hathaway, Richard R.
• Primary Examiner(s): Trammell, James
• Assistant Examiner(s): Stroud, James E
• Application Number:
  US12/890,936
• Publication Number:
  US 20120078478A1
• Time in Patent Office: 1,891 Days
• Field of Search: 701/51, 701/52, 701/53, 701/54
• US Class Current: 1/1
• CPC Class Codes: F16H 63/483 Circuits for controlling engagement of parking locks or brakes

Abstract

A method for controlling a transmission includes using actuation of a button of a shift module to produce a signal representing a desired gear, using the signal and a second signal commanding a park range to determining a priority range, using a shift mechanism to attempt engagement of the transmission in the priority range, and if the priority range is park and park is not engaged, engaging a park brake.

Claims

1. A method for controlling a transmission, comprising:

(a) using shift module button actuation to produce a signal representing a desired gear;

(b) automatically producing a second signal representing park, provided engine ignition is off or a seatbelt is unlatched, and additionally neutral hold and neutral tow are unselected;

(c) commanding park engagement if the second signal is present, otherwise commanding desired gear engagement;

(d) if park is commanded and park remains disengaged, engaging a park brake.

2. The method of claim 1, wherein step (a) is executed provided said button actuation extends for a period at least equal to a length of a reference period.

3. The method of claim 1, wherein step (a) further comprises:

awaiting the signal, provided the transmission is engaged in park, neutral hold or neutral tow.

4. The method of claim 1 wherein step (a) further comprises determining that vehicle conditions and operational vehicle components required for a change in a transmission range are present.

5. The method of claim 4 further comprising determining:

whether vehicle conditions warrant a transmission range change, wherein said vehicle conditions include at least one of operation of a brake shift interlock, vehicle speed, status of an ignition switch, opened and closed state of a vehicle door, battery voltage, operation of a communications network onboard the vehicle, presence of a neutral-tow request, status of a neutral hold, latched status of a vehicle operator'"'"'s seatbelt, operating status of a park override, operating status of a button stuck check, and operating status of a default-to-park mechanism.

6. The method of claim 1, further comprising displaying a shift fault, if a priority range is not engaged.

7. The method of claim 1, further comprising:

if a priority range is engaged, displaying a currently engaged transmission range.

8. The method of claim 1, wherein step (c) further comprises:

determining that a priority range is park, if one of an ignition switch is off, a vehicle door is open, and a seatbelt of an occupied seat is unlatched.

9. The method of claim 1, wherein step (c) further comprises:

determining that a priority range is park, if one of an ignition switch is off, a vehicle door at the driver'"'"'s position is open, and a seatbelt for the driver'"'"'s seat is unlatched.

10. The method of claim 1, wherein step (c) further comprises:

if a voltage of a battery used to actuate the shift mechanism is less than a reference voltage, using the shift mechanism to engage the transmission in the park range.

11. A method for controlling a transmission, comprising:

(a) producing a signal representing a desired gear in response to an input to a driver interface;

(b) automatically producing a second signal representing park, provided engine ignition is off or a seatbelt is unlatched, and additionally neutral hold and neutral tow are unselected;

(c) if the second signal is present, commanding park engagement, otherwise commanding engagement of the desired gear;

(d) if the commanded gear is not engaged, displaying a shift fault;

(e) if park is commanded and park remains disengaged, engaging a park brake.

12. The method of claim 11, wherein step (a) further comprises:

awaiting the signal, provided the transmission is engaged in park, neutral hold or neutral tow.

13. The method of claim 11, wherein step (a) further comprises:

awaiting the signal, provided the transmission is engaged in park, neutral hold or neutral tow, an ignition switch is on, a driver'"'"'s door is closed, a driver'"'"'s seatbelt is latched and a voltage of a battery used to actuate the shift mechanism is equal to or greater than a reference voltage.

14. The method of claim 11 wherein step (a) further comprises determining that vehicle conditions and operational vehicle components required for a change in a transmission range are present.

15. The method of claim 14 further comprising:

determining whether vehicle conditions warrant a transmission range change, wherein said vehicle conditions include at least one of operation of a brake shift interlock, vehicle speed, status of an ignition switch, opened and closed state of a vehicle door, battery voltage, operation of a communications network onboard the vehicle, presence of a neutral-tow request, status of a neutral hold, latched status of a vehicle operator'"'"'s seatbelt, operating status of a park override, operating status of a button stuck check, and operating status of a default-to-park mechanism.

16. The method of claim 11, wherein step (b) further comprises:

if a voltage of a battery used to actuate the shift mechanism is less than a reference voltage, using the shift mechanism to engage the transmission in the park range.

17. The method of claim 11, further comprising:

displaying a currently engaged transmission range.