Diagnostic system for automatic transmission
US8032274B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2007 |
| Grant date | Oct 4, 2011 |
| Priority date | — |
| Expiry date | Nov 14, 2028 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16H2200/2051
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A diagnostic system for an automatic transmission is provided in which a microcomputer determines that torque that can drive the driving wheels of the vehicle is not transmitted to an output shaft of the automatic transmission when the vehicle is stopped and the ignition key is operated to the OFF position, and performs forced energization of solenoids of solenoid valves associated with respective friction devices of the transmission, while monitoring current passing through the solenoid valves. If the current monitored does not match the current for energizing any of the solenoids, the microcomputer determines that the corresponding solenoid valve is at fault. Thus, the diagnostic system appropriately determines the presence of a fault of each solenoid valve for controlling the hydraulic pressure to each friction device, with increased flexibility and freedom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.