Clutch to clutch tie-up steady-state diagnostic
AssigneeGM Global Technology Operations LLC
InventorTodd J. Thor
Life of this patent
Estimating the term…
Abstract
A method of regulating operation of an automatic transmission includes identifying a tie-up condition of the automatic transmission, adjusting a pressure of a transmission element in response to the tie-up condition and determining whether a first gear ratio of the automatic transmission holds. The pressure is set to zero if the gear ratio does not hold and a faulty transmission element is identified as one associated with a second gear ratio that is lower than said first gear ratio.
Claims15
A transmission control system for an automatic transmission, comprising:
- a first module that identifies a tie-up condition of the automatic transmission;
- a second module that adjusts a pressure of a transmission element in response to said tie-up condition;
- a third module that determines whether a first gear ratio of the automatic transmission holds, wherein said second module sets said pressure to zero if said gear ratio does not hold;
- and
- a fourth module that identifies a faulty transmission element as one associated with a second gear ratio that is lower than said first gear ratio.
A method of regulating operation of an automatic transmission, comprising:
- identifying a tie-up condition of the automatic transmission;
- adjusting a pressure of a transmission element in response to said tie-up condition;
- determining whether a first gear ratio of the automatic transmission holds;
- setting said pressure to zero if said gear ratio does not hold;
- and
- identifying a faulty transmission element as one associated with a second gear ratio that is lower than said first gear ratio.
A method of regulating operation of an automatic transmission, comprising:
- identifying a tie-up condition of the automatic transmission;
- determining a slip pressure of a transmission element;
- adjusting a pressure of said transmission element to a pressure just above said slip pressure in response to said tie-up condition;
- determining whether a first gear ratio of the automatic transmission holds;
- setting said pressure to zero if said gear ratio does not hold;
- identifying a faulty transmission element as one associated with a second gear ratio that is lower than said first gear ratio;
- wherein said pressure just above said slip pressure is determined as a sum of said slip pressure and an offset pressure.
Dependencies are inferred from the claim text.