Abstract: A system and method for selectively engaging and disengaging auxiliary equipment to avoid gear clash in a vehicle is disclosed. The system includes a transmission, a transfer case, and a transmission controller. The transmission has a plurality of gears for establishing a plurality of gear ratios. The transfer case is coupled to the transmission by an output shaft. The transmission controller is in communication with a plurality of control devices for controlling the operation of the transmission. The controller includes control logic for controlling the engagement and disengagement of the auxiliary equipment.

Abstract: A method for controlling a transmission in a motor vehicle includes determining a temperature of a fluid in the transmission, determining whether the torque converter lockup clutch is applied, and determining an engine torque of the motor vehicle. Then, the torque converter lockup clutch is applied and the transmission is prohibited from up-shifting if the temperature of the fluid exceeds a threshold, the torque converter lockup clutch is not applied, and the engine torque exceeds a second threshold. Next, a tractive effort of the motor vehicle is determined and the torque converter lockup clutch is deactivated when the temperature of the fluid is less than a third threshold, the tractive effort is less than a fourth threshold, or the engine torque is less than the second threshold.

Abstract: A control system operable to engage a torque transmitting mechanism, the control system having at least one variable bleed solenoid valve operable to selectively provide pressurized fluid to selectively engage at least one torque transmitting mechanism. An electronic control unit is also provided to provide control to the at least one variable bleed solenoid valve. The electronic control unit commands the variable bleed solenoid valve to provide the pressurized fluid to the at least one torque transmitting mechanism for a first predetermined time and to subsequently substantially disallow the pressurized fluid to the at least one torque transmitting mechanism for a second predetermined time subsequent to the first predetermined time. The electronic control unit subsequently commands an intermediate pressure level to trim the torque transmitting mechanism into engagement. A method for providing engagement to the torque transmitting mechanism is also provided.

Abstract: A method of controlling a driveline retarder of a powertrain including a transmission having a rotatable input shaft connected to an engine and an output shaft connected to the driveline retarder is provided. The method includes determining a set speed value and comparing the set speed value plus a customer modifiable constant value to a current rotational speed value of the output shaft. A driveline retarder cruise modulation torque request value is then calculated when the current rotational speed value of the output shaft is greater than or equal to the set speed value plus the customer modifiable constant value. The driveline retarder is controlled as a function of the driveline retarder cruise modulation torque request value. A powertrain configured to implement the aforementioned method is also disclosed.

Abstract: A method for determining the condition of a transmission fluid filter and controlling an operator indicator to alert the operator that the fluid filter requires replacement is disclosed. The method includes monitoring a fluid pressure switch, determining an operating mode of the transmission, determining whether the operating mode of the transmission is changing, activating a timer if the operating mode is changing, recording the time, comparing the time to a predefined time threshold, determining whether the recorded time is greater than the predefined threshold, and activating the operator indicator to indicate that the fluid filter requires replacement if the recorded time is greater than the predefined threshold.

Abstract: The method of the present invention is adapted to control transmission oil temperature. According to a preferred embodiment, the engine coolant temperature may be controlled in addition to or regardless of transmission oil temperature. To maintain transmission and/or engine temperature, the present invention is preferably configured to limit the engine's power when required to ensure the powertrain (engine and transmission) does not overheat.

Abstract: A transmission control method comprises the steps of determining whether a shift requiring an output shaft lock-up is commanded, wherein such a shift involves a first torque transmitting mechanism either being applied or released while a second torque transmitting mechanism is held engaged. The control determines whether the vehicle is stopped by one or all of the following: verifying the vehicle service brakes are applied, the transmission output speed is near zero, the engine speed is low, the oil sump temperature is greater than a calibration temperature, and the turbine speed is near zero if the vehicle is in forward drive. If the vehicle is stopped, a lock-up torque transmitting mechanism is applied prior to the shift operable to prevent torque transmission to the output shaft. When the lock-up mechanism reaches capacity, the shift proceeds by one of applying and releasing the first mechanism, while maintaining the second mechanism engaged.