System and Method for Detecting Clutch-Related Faults in an Automatic Transmission
AssigneeAllison Transmission, Inc.
InventorsCharles F. Long, Darren J. Weber, John William Edward Fuller
Life of this patent
Estimating the term…
Abstract
A fault diagnostic method for an automatic transmission may include monitoring an operating state of a trim system configured to selectively supply clutch engagement pressure and exhaust to at least one clutch control valve, determining an expected operating state of the trim system based on current operating conditions of the transmission, and generating a fault signal if the monitored operating state of the trim system is different from the expected operating state of the trim system.
Claims21
1-20. (canceled)
A system for an automatic transmission, the system comprising:
- a trim system configured to selectively (i) supply clutch engagement pressure to at least one clutch control valve via first and second fluid passageways and (ii) exhaust the first and second fluid passageways;
- and
- a first pressure switch fluidly coupled to the trim system,
- wherein the first pressure switch is (i) in a first operating state when the trim system supplies the clutch engagement pressure to the first and second fluid passageways and (ii) in the first operation state when the trim system exhausts both the first and second fluid passageways.
A system for detecting clutch-related faults in an automatic transmission, the system comprising:
- a trim system configured to selectively (i) supply clutch engagement pressure to a first fluid passage and (ii) exhaust the first fluid passageway;
- a first control valve fluidly coupled to the trim system via the first fluid passageway;
- a first pressure switch fluidly coupled to the first control valve such that the first pressure switch is in a first operating state when the first control valve is de-stroked and is in a second operating state when the first control valve is stroked;
- and
- a transmission control circuit to monitor the operating state of the first pressure switch, determine a predefined operating state of the first pressure switch based on current operating conditions of the transmission, and generate a first control valve fault signal in response to a determination that the monitored operating state of the first pressure switch is different from the predefined operating state of the first pressure switch.
Dependencies are inferred from the claim text.