Abstract: A controller is provided to, in response to a speed of the vehicle exceeding an allowable speed based on a measured grade while the vehicle is running and in neutral or park, actuating a vehicle holding mechanism to stop the vehicle.

Abstract: A controller is provided to, in response to a speed of the vehicle exceeding an allowable speed based on a measured grade while the vehicle is running and in neutral or park, actuating a vehicle holding mechanism to stop the vehicle.

Abstract: A transmission control circuit 10 which is adapted for use with an electronically controlled transmission having several transmission control solenoids 12, 14 and 16 and a selectively positionable gear selector 18. Circuit 10 includes a conventional controller 20, electrical switches 22, 24 and 26, a transmission range sensor 28, and vehicle sensors 32. Transmission range sensor 28 is ganged with switches 22, 24 and 26 and is further communicatively coupled to controller 20. Switches 22, 24 and 26 are operatively coupled to gear selector 18 and are respectively and operatively disposed between a battery 30 and solenoids 12, 14 and 16. Switches 22, 24 and 26 are effective to selectively connect and disconnect solenoids 12, 14 and 16 to/from battery 30, thereby selectively enabling and disabling solenoids 12, 14 and 16.

Abstract: A shift control and shift strategy for an automatic transmission in an automotive vehicle driveline wherein the automatic ratio shift schedule can be disabled selectively to accommodate a manual ratio shift control. A driver-operated mode selection switch permits the operator to select normal automatic ratio control or a launch-assist mode during operation in the normal ratio shift mode. Ratio changes occur in response to driveline operating variables in a vehicle launch-assist mode. The transmission control system is commanded to effect a high speed ratio when the vehicle is stationary with the brakes applied. The operating mode defaults to a normal ratio shift mode as the operator releases the wheel brakes. In an alternative embodiment of the invention, the control includes multiple enable switches for achieving manual selection of the ratios when a manual upshift sequence is desired.

Abstract: A method for determining the onset of positive torque through an automatic transmission (the power-on point), includes saving engine torque magnitudes within a specified tolerance of each other and within a adaptive limits, the highest torque value of the sampled torque magnitudes being stored in memory. The saved value plus a calibrated safety margin is used to compare to the calculated transmission input torque. If the input torque is higher, the powertrain is considered “power-on.” In addition to the safety margin, other calibratable adder torque values can be used to compensate for air conditioning, electrical loads, temperature, etc. If the samples fall below the lower adaptive limit, the lower limit is used plus any torque adders. If the adaptive samples are above the adaptive limit, the upper adaptive limit is used without any torque adders. A calibrated baseline torque value is used for power-on determination until enough valid samples are obtained.

Abstract: A method and apparatus are provided to determine a failure of an automatic transmission temperature sensor in an automobile. The apparatus detects a start-up of the vehicle. A sensor detects the transmission fluid temperature. The transmission fluid temperature at start-up is checked to see if the temperature is below a first predetermined temperature or above a second predetermined temperature. If the sensor does not detect a predetermined change in temperature during operation of the vehicle after it is determined the transmission fluid temperature at start-up is above the first predetermined or below the second predetermined temperature, the sensor has failed.

Abstract: A method and system for testing the functionality of a solenoid used to change the apply state of a torque converter clutch in a vehicle having an electronic control unit and a driveline system including an engine, a transmission, a torque converter. A first torque converter speed ratio is established. The commanded apply state of the torque converter clutch is determined, then a second torque converter speed ratio is calculated using engine speed and output shaft speed. The functionality of the torque converter clutch solenoid is established by determining whether the torque converter clutch solenoid has changed the applied state of the torque converter clutch by performing a comparison of the first and second torque converter speed ratios.