Transmission with electronic range selector and pull out of park control logic

摘要

A vehicle includes a transmission, and an Electronic Transmission Range Selection (ETRS) system. The transmission has a plurality of clutches, a park pawl, and a park sensor. The ETRS system has a controller and an electronic range selector device. The controller is programmed to detect a delay in pull out of the park pawl from a park position and to control an action of the vehicle in response to the delay by receiving an electronic range request signal to shift from a park operating range to another operating range; receiving a park pawl position signal from the park sensor; determining if pull out of the park pawl from the park position has not occurred by a predetermined time; and increasing one of a line pressure, a clutch pressure, and an idle speed if pull out of the park pawl from the park position has not occurred by the predetermined time.

主权项

1. A vehicle comprising:
an engine having an idle speed; a transmission connected to the engine and having:
a hydraulic pressure source for supplying a hydraulic fluid at a line pressure;a plurality of clutches, each having a respective clutch pressure;a shift valve that is in fluid communication with the hydraulic pressure source and the plurality of clutches, wherein the shift valve is operable to shift the transmission to a requested operating range via the plurality of clutches;a park pawl that is pulled out of a park position to shift the transmission out of a park operating range via one or more of the clutches when the transmission is requested to shift from the park operating range to another operating range; anda park sensor configured to determine if the park pawl is pulled out of the park position; and an electronic transmission range selection (ETRS) system having a controller and an electronic range selector device, wherein the electronic range selector device is operable to transmit an electronic range request signal to the controller to request a shift of the transmission to the requested operating range; wherein the controller is programmed to detect a delay in pull out of the park pawl from the park position when the transmission is requested to shift from the park operating range to another operating range, and to control an action of the vehicle in response to the delay by:
receiving the electronic range request signal to shift from the park operating range to another operating range from the electronic range selector device;receiving a park pawl position signal from the park sensor indicative of the park pawl being pulled out of the park position;determining if pull out of the park pawl from the park position has not occurred by a predetermined time after the range request signal has been received; andincreasing one of the line pressure, the clutch pressures, and the idle speed if pull out of the park pawl from the park position has not occurred by the predetermined time.