Apparatus and method for providing automatic shift modes in an automatic transmission

A method and apparatus for providing first and second automatic shift modes for an automatic transmission. Shifting of the automatic transmission is controlled by a transmission controller. The driver selects a control mode by manipulating an input device. The controller controls the operation of the automatic transmission using a first set of operating characteristics and a second set of operating characteristics in response to receiving the first mode signal and the second mode signals, wherein the first and second sets of operating characteristics include engine management characteristics.

I. FIELD OF THE INVENTION
 The present invention relates generally to an apparatus and method for
 providing an automatic transmission, and more particularly, to an
 apparatus and method for providing an apparatus and method for changing
 the operating characteristics of an automatic transmission.
 II. BACKGROUND ART
 Automotive vehicles require a power train to transmit the force of an
 engine to the wheels of the vehicle. The power train's main component is
 typically referred to as the transmission. The transmission converts
 engine speed and torque in accordance with the tractive-power demand of
 the vehicle. Transmissions are generally, either manually or automatically
 actuated. Manual transmissions generally include mechanical mechanisms for
 coupling rotating gears to produce different ratio outputs to drive the
 wheels. Automatic transmissions are designed to take automatic control of
 the frictional units, gear ratio selection and gear shifting.
 Vehicles equipped with automatic transmissions are generally easier to
 operate with a gear selection process generally adapted to favor fuel
 economy and smooth shifts. However, some drivers may favor the more
 aggressive performance and feel of a manual transmission in exchange for
 lower fuel economy.
 The present invention is aimed at overcoming one or more of the problems as
 set forth above.
 III. SUMMARY OF THE INVENTION
 In one aspect of the present invention, an apparatus for providing first
 and second automatic shift modes for an automatic transmission is
 provided. The apparatus includes an input device adapted to produce one of
 a first and second mode signals in response to manipulation by a driver. A
 plurality of sensors is coupled to the automatic transmission. The sensors
 sense a plurality of parameters related to the automatic transmission and
 produce a plurality of respective sensor signals. A controller is coupled
 to the automatic transmission and the input device. The controller is
 adapted to receive the sensor signals and the one of the first and second
 mode signals and automatically shift the automatic transmission in
 response to the sensor signals and the one of the first and second mode
 signals. The controller is programmed to provide first and second sets of
 operating characteristics for automatic operation of the automatic
 transmission in response to receiving the first and second mode signals,
 respectively. The first and second sets of operating characteristics
 include engine management characteristics.
 In another aspect of the present invention, a method for providing first
 and second automatic shift modes for an automatic transmission is
 provided. The method includes the steps of receiving one of a first and
 second mode signals in response to selection by a driver and sensing a
 plurality of parameters related to the automatic transmission and
 producing a plurality of respective sensor signals. The method further
 includes the step of receiving the sensor signals and the one of the first
 and second mode signals, automatically shifting the automatic transmission
 as a function of the sensor signals and a first set of operating
 characteristics in response to receiving the first mode signal and a
 second set of operating characteristics in response to receiving the
 second mode signals. The first and second sets of operating
 characteristics include engine management characteristics.

V. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 With reference to the drawings, and in operation, the present provides an
 apparatus 102 and method for providing first and second automatic shift
 modes for an automatic transmission.
 A. Operation of the Automatic Transmission--Overview
 With specific reference to FIG. 1, the automatic transmission 104 is shown
 having a valve body 106 and an output shaft 108. The automatic
 transmission 104 provides a gearing interface between two driven wheels
 110A, 110B (only one of which are shown) and an internal combustion engine
 112 to adjust the torque and speed provided to output shaft 108 from the
 internal combustion engine 112.
 The automatic transmission 104 can select between four or five gear ratios,
 three or four forward gear ratios and one reverse gear ratio, for
 providing the optimum gear ratio between the output shaft 108 and the
 internal combustion engine 112. To change from one gear ratio to another,
 the valve body 106 hydraulically communicates with a plurality of bands,
 gears, and clutches (not shown) to cause clamping thereof around various
 portions of planetary gear sets (not shown) within the automatic
 transmission 104.
 This clamping and unclamping regulates the rotation of the planetary gear
 sets which, in turn, selects a specific gear ratio for automatic
 transmission 104. The output shaft 108 is coupled to the driven wheels
 110A, 110B through a differential 114 to drive the vehicle 116.
 Referring to FIG. 1, a controller or electronic control module 118
 electrically communicates with valves 120, 122, 124 of valve body 106 to
 actuate various combinations of bands and clutches to adjust the gear
 ratio as discussed above.
 The controller 118 includes a processor. The term processor is meant to
 include microcomputers, microprocessors, integrated circuits, etc . . .
 all of which are capable of being programmed. The controller 118 is
 adapted to receive input signals from various sensors and input devices
 and to responsively control the automatic transmission 112.
 Each valve 120, 122, 124 is operated by an electronically controlled
 solenoid (not shown) which is actuated by the controller 118 to apply or
 remove hydraulic pressure to specific bands or clutches, thereby adjusting
 the gear ratio of automatic transmission 104.
 To determine the proper gear ratio for automatic transmission 104, the
 controller 118 must analyze a number of factors which include the current
 gear ratio of automatic transmission 104, speed of vehicle 118 (as a
 function of the transmission output speed), throttle position and engine
 speed, i.e., input speed of the automatic transmission 104.
 A plurality of sensors are coupled to the automatic transmission 104 and
 are adapted to sense a plurality of parameters related to the automatic
 transmission 104 and produce a plurality of respective sensor signals. In
 the preferred embodiment, the plurality of sensors includes an input speed
 sensor 126, an output speed sensor 128, a throttle position sensor 130,
 and an engine speed sensor 132.
 The input speed sensor 126 determines the rotational input speed of the
 automatic transmission 104. Likewise, the output speed sensor 128 provides
 an input to controller 118 representative of the velocity at which the
 vehicle 116 is traveling. To determine the present gear ratio in which the
 automatic transmission 104 is operating, the input speed sensor 126 is
 compared to the output speed sensor 128. The ratio of these sensors is
 determinative of the gear ratio of automatic transmission 104.
 The throttle position sensor 130 detects the amount of opening of a
 throttle blade 132. Lastly, the engine speed sensor 132 determines the
 revolutions per minute in which internal combustion engine 112 is turning.
 The current gear ratio of the automatic transmission 104 is determined by
 the controller 118 and is a function of a selected position of an input
 device 136 and the measured parameters.
 With reference to FIG. 2, in the preferred embodiment the input device 136
 includes a gear shift lever 202. Typically, the gear shift lever 202 has a
 number of positions, for example, park, overdrive, one or more low gear
 positions (not shown), neutral and reverse. As shown, the gear shift lever
 202 is movable along a first axis 204 to select one of the transmission
 modes.
 The low gear positions limit the gear ratio, to one of the lower gears,
 e.g., second or third. The reverse position places the transmission in the
 reverse gear.
 When the gear shift lever 202 is in the overdrive position the automatic
 transmission 104 and the controller 118 are selected to be in a first
 automatic mode, i.e., overdrive. In the first automatic mode, the
 controller 118 selects one of the forward gears based on vehicle
 parameters and a set of shift schedules (usually stored in lookup tables).
 Generally, the automatic transmission is designed to maximize fuel economy
 and provide smooth shifts while in the first automatic mode.
 The above described automatic transmission and variations and modifications
 thereof are well known in the art. As such, the skilled artisan will
 appreciate that the present invention may be used with any of these
 modifications or variations and is not limited to the automatic
 transmission described herein.
 B. Operation of the Automatic Transmission in First and Second Automatic
 Modes
 1. Overview
 As stated above, the first automatic mode of operation is aimed at
 maximizing fuel economy. However, an operator may desire a more
 "aggressive" feel and performance driven transmission. The present
 invention provides a more aggressive operation via a second automatic
 mode.
 In the preferred embodiment, the driver selects one of the first and second
 modes via the input device 136. As discussed below, the input device
 includes a first mode position and a second mode position. When the driver
 places the input device 136 in the first mode position or the second mode
 position, a respective first mode signal or second mode signal is
 produced.
 As in the first automatic mode, in the second automatic mode the
 transmission controller 118 selects one of the forward gears based on
 vehicle parameters and a set of shift schedules (usually stored in lookup
 tables). To achieve the desired performance characteristics in the
 transmission, the present invention modifies operation of the transmission
 using one or more of the methods discussed below.
 With reference to FIG. 3, the general operation of the present invention in
 accordance with an embodiment of the present invention will now be
 described. In a first control block 302, the driver selects one of the
 first or second automatic control modes. In a first decision block 304, if
 the first mode was selected by the driver then control proceeds to a
 second control block 306. Otherwise control proceeds to a third control
 block 308.
 In the second control block 306, the automatic transmission 104 is
 controlled automatically using a set of first mode or operating
 characteristics (see below). In the third control block 308, the automatic
 transmission 104 is controlled automatically using a set of second mode or
 operating characteristics (see below).
 As described above, the controller 118 is coupled to the automatic
 transmission 104 and the input device 136 and is adapted to receive the
 signals from the sensors 126, 128, 130, 132 and the first mode signal or
 second mode signal produced by the input device 136. The controller 118
 automatically shifts the automatic transmission 104 in response to the
 sensor signals and the received mode signal. The controller 118 is
 programmed to provide a first set of operating characteristics in response
 to receiving the first mode signal and to provide a second set of
 operating characteristics in response to receiving the second mode signal.
 2. Transmission Shifting Using Shift Schedules
 With reference to FIG. 4, operation of an exemplary automatic transmission
 in the first automatic mode is illustrated with respect to a shift
 schedule. The transmission controller 118 uses the shift schedule to
 determine if and when a shifting of the transmission 104 should occur
 based on the vehicle speed and the position of the throttle.
 The line segments 402, 404, 406 represent transmission upshifts from the
 first gear ratio to the second gear ratio, from the second gear ratio to
 the third gear ratio, and from the third gear ratio to the fourth gear
 ratio, respectively. For example, if vehicle speed and throttle position
 are to the left of dashed line 402, then the automatic transmission is in
 first gear. If vehicle speed and throttle position are to the right of
 line segment 402 then the automatic transmission is in second gear. As
 vehicle speed and throttle position cross line segment 402 (from upper
 left to bottom right), the transmission controller 118 commands a shifting
 of the automatic transmission from first gear to second gear.
 Similarly, line segments lines 408, 410, 412 represent transmission
 downshifts from the second gear ratio to the first gear ratio, from the
 third gear ratio to the second gear ratio and from the fourth gear ratio
 to the third gear ratio, respectively.
 In the preferred embodiment, the shift schedules are implemented using look
 up tables.
 With reference to FIG. 5, the shift schedules may be adjusted to achieve a
 more performance feel to the shifting while in the second automatic mode.
 As shown, portions of one or more of the upshift line segments 502, 504,
 506 may be shifted to the right (along the X axis) and/or down (along the
 Y axis) with respect to line segments 402, 404, 406. During upshifting
 this has the effect of delaying the shift to a higher gear ratio. In other
 words, the lower gear ratio is maintained longer, supplying more torque
 and thus greater acceleration.
 Additionally, portions of one or more of the downshift segments 508, 510,
 512 may be shifted to the right and/or down, as shown. This has the effect
 of allowing a kickdown earlier and allowing a lower gear ratio at a higher
 speed.
 3. The Hold in Gear Function
 When the vehicle 116 is traveling at a relatively high rate of speed and
 constant velocity, the transmission controller 118 senses engine speed and
 throttle position and places the automatic transmission 104 in a high gear
 ratio, i.e., third or fourth gear, producing a high speed and low torque
 at the wheels. If the driver desires to rapidly accelerate, such as in
 passing another vehicle, the driver moves the throttle to a substantially
 open or wide open position. Under these conditions, the transmission
 controller 118 senses the changed throttle position and shifts the
 automatic transmission to a lower gear ratio, producing more torque at the
 wheels and greater acceleration. When the throttle is reduced, the
 controller 118 shifts the automatic transmission back to a higher gear
 ratio.
 However, there are some situations when it is desirable to "hold" the gear
 in the lower gear ratio. For example, when the driver is passing another
 vehicle, the driver will accelerate and the automatic transmission will
 downshift to a lower gear ratio, as described above. Typically, the driver
 will pass the other vehicle, reduce throttle, to check the vehicle's
 position and then accelerate again. When the throttle is reduced, the
 transmission controller 118 will attempt to shift the automatic
 transmission 104 back into the higher gear ratio (based on the shift
 schedule). When the throttle is thereafter increased, the automatic
 transmission will downshift again to provide acceleration. Since this
 occurs in a short period of time, the controller 118 produces an
 undesirable downshift, upshift, downshift combination resulting in "jerky"
 operation.
 In this situation it is desirable to delay shifting of the automatic
 transmission into the higher gear ratio for a period of time (for example,
 0.5 seconds) in order to eliminate the undesired upshift.
 With reference to FIG. 6, a driving scenario using the Hold in Gear
 function is described. The vehicle 116 begins at time 0 traveling at a
 relatively high speed with the throttle position about 30 percent until
 time=2 seconds. At 2 seconds, the vehicle driver rapidly depresses the gas
 pedal and opens the throttle to approximately 65 percent. The speed of the
 vehicle 116 and throttle position causes the controller 118 to downshift
 the automatic transmission 106 into third gear. At time=4 seconds, the
 vehicle driver takes his foot off the gas pedal, thereby causing the
 opening of the throttle to be reduced to 1 percent at time=4.2. At
 time=4.7 seconds, the driver opens the throttle again to 65 percents. At
 time=6 seconds, the driver begins to open the throttle.
 As discussed previously, based on the normal shift schedules the controller
 118 would normally instruct the automatic transmission 104 to upshift back
 into fourth gear. However, the Hold in Gear function causes the controller
 118 to delay upshifting of the automatic transmission 106. As such, the
 automatic transmission 106 remains in third gear until time=6.7 seconds,
 at which point the controller 118 allows the automatic transmission 106 to
 resume its normal shift pattern.
 This "hold-in-gear" function is disclosed in commonly owned U.S. Patent
 Application, entitled "Method and Apparatus for Controlling Upshift on an
 Automatic Transmission", U.S. application Ser. No. 09/283,456 filed on
 Apr. 1, 1999, by Rita D. Hollingsworth, Colt R. Correa, and Scott A.
 Miller, which is hereby incorporated by reference.
 In one embodiment, the Hold in Gear feature is disabled in the first
 automatic mode and enabled in the second automatic mode.
 In another embodiment, the detection threshold, i.e., tip-out, for enabling
 the hold in gear function feature is modified. Tip-out occurs when the
 throttle is quickly released from a substantially open position to a
 substantially closed position. A tip-out condition is detected when the
 rate of decrease in the throttle position exceeds a predetermined
 threshold. In the another embodiment, the threshold is adjusted.
 Preferably, TH.sub.FIRST.sub..sub.-- .sub.AUTOMATIC.sub..sub.-- .sub.MODE
 is greater than TH.sub.SECOND.sub..sub.-- .sub.AUTOMATIC.sub..sub.--
 .sub.MODE, where TH.sub.FIRST.sub..sub.-- .sub.AUTOMATIC.sub..sub.--
 .sub.MODE is the threshold used in the first automatic mode and
 TH.sub.SECOND.sub..sub.-- .sub.AUTOMATIC.sub..sub.-- .sub.MODE is the
 threshold used in the second automatic mode.
 4. Torque Converter Lock-up Schedule
 A torque converter 138 selectively couples the engine 112 and the automatic
 transmission 104. The transmission controller 118 is adapted to lockup the
 converter 138 under certain conditions. Typically the conditions are
 defined in terms of throttle position and vehicle speed. With the torque
 converter 138 locked, engine efficiency is increased, but less torque is
 available at the driven wheels 110A, 110B.
 With reference to FIG. 7, operation of the automatic transmission 104 and
 the torque converter lock-up feature in the first automatic mode will now
 be discussed.
 Typically, the torque converter 138 will not be allowed to lock when the
 vehicle 116 is traveling below a predefined speed, for example, 30 miles
 per hour (MPH).
 The first automatic mode third gear lockup trace 702 and the first
 automatic mode third gear unlock trace 704 represent the locking and
 unlocking of the torque converter while the automatic transmission 104 is
 in the third gear ratio.
 With the automatic transmission 104 in third gear, when throttle position
 and vehicle speed cross the first automatic mode third gear lockup trace
 702 (from upper left to lower right), the transmission controller 118
 locks the torque converter 138.
 With the automatic transmission 104 in third gear, when the throttle
 position and vehicle speed cross the first automatic mode third gear
 unlock trace 704 (from lower right to upper left), the transmission
 controller 118 unlocks the torque converter 138.
 Likewise, first automatic mode fourth gear lock and unlock traces 706,708
 represent the locking and unlocking of the torque converter 138 while the
 automatic transmission 104 is in the fourth gear ratio.
 With the automatic transmission 104 in the fourth gear, when throttle
 position and vehicle speed cross the first automatic mode fourth gear lock
 trace 606 (from upper left to lower right), the transmission controller
 118 locks the torque converter 138.
 With the automatic transmission 104 in the fourth gear, when the throttle
 position and vehicle speed cross the first automatic mode fourth gear
 unlock trace 708 (from right to left), the transmission controller 118
 unlocks the torque converter.
 With reference to FIG. 8, operation of the automatic transmission 104 and
 the torque converter lock-up feature in the second automatic mode will now
 be discussed. In order to provide a more aggressive feel, torque converter
 lock-up will be delayed. First, the vehicle speed threshold is raised,
 i.e., the torque converter will not be locked until a higher vehicle speed
 is obtained, e.g., 37 MPH.
 Additionally, portions of one or more of the torque converter lock and
 unlock traces 802, 804,806, 808 may be shifted up and to the right (with
 respect to traces 702, 704, 706, 708).
 5. Shifting the Transmission to a Lower Gear Ratio
 With reference to FIG. 9, operation of the automatic transmission 104 and
 the controller 118 in the first automatic mode is illustrated during a
 kickdown operation.
 First, the controller determines that a down shift is required (based on
 vehicle speed and throttle position using the shift schedule). The trace
 902 represents the output of the shift schedule, i.e., the call for a
 kickdown to change the gear ratio. In order to accomplish the downshift,
 the controller 118 sets a desired output acceleration (trace 904) of the
 transmission. The desired output acceleration is used to determine how
 quickly the clutches should engage and reach the new gear ratio.
 Transmission output speed and transmission input (torque converter turbine)
 speed increase (traces 906, 908, respectively). When the transmission
 controller 118 calls for a kickdown, the controller 118 actuates the
 appropriate valves 120, 122, 124 to release and engage the clutches needed
 to shift the automatic transmission 104. Once the correct gear ratio is
 achieved (transmission output speed vs. transmission input speed), the
 controller 118 completely engages the clutches. As shown in FIG. 9, the
 clutches are fully engaged and the desired gear ratio is achieved at
 approximately 5.02 seconds (line segment 910).
 The valves are electronically controlled to provide hydraulic fluid to the
 clutches. Engagement of a clutch has two phases. First, the clutch must be
 filled with hydraulic fluid. Once filled, the clutch will begin to engage
 as additional fluid flow is provided until it is fully engaged. The rate
 of fluid flow during each of these phases controls the rate and "feel" of
 the shifting operation. As stated above, in the first automatic mode
 control of the shifting of the automatic transmission 104 down to a lower
 gear is designed for a smooth shift.
 With reference to FIG. 10, operation of the automatic transmission 104 and
 the controller 118 in the second automatic mode is illustrated during a
 kickdown operation.
 First, the controller determines that a kickdown is required (based on
 vehicle speed and throttle position using the shift schedule). Trace 1002
 represents the output of the shift schedule. In order to accomplish the
 kickdown, the controller 118 sets a desired output acceleration (trace
 1004) of the transmission.
 When the shift schedule demands a kickdown, electronically controlled
 solenoids (not shown) begin to actuate the appropriate valves 120,122, 124
 to release and engage the clutches needed to shift the automatic
 transmission 104.
 Transmission input speed and transmission output (torque converter turbine)
 speed increase (traces 1006, 2008, respectively). Once the output and
 input speeds reach the desired gear ratio, the shift is completed by fully
 engaging the correct clutches. torque converter output speed) is achieved,
 the controller 118 actuates the appropriate valves 120, 122,124 to release
 and engage the clutches needed to shift the transmission 104. As shown in
 FIG. 10, the clutches are fully engaged and the desired gear ratio is
 achieved at approximately 4.52 seconds (line segment 1010).
 The rate of fluid flow during each of the phases of clutch engagement
 controls the rate and "feel" of the shifting operation. In the second
 automatic mode, the kickdown is made more aggressive by providing crisper,
 quicker downshift times by modifying the rate at which the respective
 clutches are filled and engaged. This is accomplished by modifying the
 hydraulic fluid flow rate through the corresponding valves 120,122,124.
 For example, as shown in FIG. 9 the downshift occurs approximately 0.5
 seconds quicker in the second automatic mode than the first automatic
 mode.
 6. Engine Management
 The controller 118 is coupled to an engine controller (not shown) to
 provide information relative to its control of the engine 112. The engine
 controller controls the engine based on the information received from the
 transmission controller 118 to reduce wear on the transmission.
 During a shift operation, energy is absorbed by the clutches until the new
 gear ratio is achieved. The applying clutch slips at a rate determined by
 the controller 118 while the releasing clutch is still engaged. This
 assists in providing a smooth shift operation. However, high input power
 during the slip and apply portions creates excessive wear on the clutch
 elements.
 In the preferred embodiment, the engine controller is adapted for
 controlling, inter alia, electronically controlled fuel injectors which
 provide fuel to the engine. During a shifting operation, the engine
 controller reduces the power input to the automatic transmission 104. This
 is known as torque management. Torque management may be performed by
 reducing the amount of fuel supplied to the engine, e.g., turning off one
 or more fuel injectors during the shifting operation.
 Additionally, when the vehicle is decelerating and throttle position is
 closed or substantially closed, one or more of the injectors may be turned
 off for a predetermined period of time. In this situation, the engine 112
 will be driven by the wheels 110 via the transmission and will assist in
 slowing the vehicle 116.
 The transmission controller 118 performs torque management by instructing
 the engine controller to reduce the power input to the transmission 104.
 In the second automatic mode, a more aggressive torque management scheme is
 used. In other words, the amount of fuel supplied to the engine is
 reduced, but to a lesser extent than in the first mode.
 In the preferred embodiment, torque management is performed by instructing
 the engine controller to turn off a specified number of fuel injectors. In
 the second automatic mode, the engine controller is instructed to leave on
 more injectors than in the first automatic mode.
 Additionally, when the vehicle is decelerating and throttle position is
 closed or substantially closed, the fuel supplied to the engine may also
 be reduced by turning off one or more of the injectors for a predetermined
 period of time. In this situation, the engine 112 will be driven by the
 wheels 110 via the automatic transmission and will assist in slowing the
 vehicle 116. In the second automatic mode, this type of engine management
 may also be more aggressive, i.e., closing or reducing the fuel supplied
 to the engine more quickly or to a greater extent.
 7. Selection of One of the First and Second Automatic Modes.
 Selection of the first automatic mode is performed by placing the gear
 shift lever in the overdrive position (the circled "D") in a conventional
 manner.
 In the illustrated embodiment, the present invention is provided in
 conjunction with an apparatus for manually shifting the automatic
 transmission. (see below). As shown in FIG. 2, the input device 136 is
 provided with a "+" and a "-" position which are used by the driver to
 indicate a desired upshift or downshift, respectively. In the preferred
 embodiment, to place the apparatus 102 in the second automatic mode the
 gear shift lever is pulled past the overdrive position. If the gear shift
 lever 202 is placed in this position, the controller 118 automatically
 controls the automatic transmission 104 in accordance with the second
 automatic mode as described above. In another embodiment, the second
 automatic mode of the automatic transmission is selected by placing the
 gear shift lever in the first automatic mode position, i.e., overdrive,
 and actuating an additional switch or pushbutton (not shown).
 C. Manual Operation of the Automatic Transmission
 The controller 118 is coupled to the automatic transmission 104 and to the
 input device 134. The driver of the vehicle 116 manipulates the gear shift
 lever 202 to operate the automatic transmission in the automatic modes and
 to manually operate the automatic transmission 104 and to select the
 manual mode (see below).
 With reference to FIG. 2, in the preferred embodiment the input device 134
 is integral with a gear shift lever 202. The gear shift lever 202 is
 operable along a first linear axis 204 for operation of the automatic
 transmission in its automatic modes in the conventional manner.
 The gear shift lever 202 is also operable along a transverse linear axis
 206. Operation of the gear shift lever 202 along the transverse linear
 axis 206 enters directs the controller 118 to manually control the
 automatic transmission 104.
 In the manual mode, the current gear of the automatic transmission 104 is
 chosen by the user through operation of the gear shift lever 202 along the
 transverse axis 206. Movement of the gear shift lever 202 along the
 transverse axis 206 towards the "+" will direct the controller 118 to
 shift the automatic transmission 104 to the next gear. Movement of the
 gear shift lever 202 along the transverse axis 206 towards the "-" will
 direct the controller 118 to (down) shift the automatic transmission 104
 to the previous gear. Movement of the gear shift lever 202 along the
 transverse axis 206 triggers first and second switches 208, 210 which
 transmit respective signals to the controller 118.
 Operation of an automatic transmission in a manual mode using a gear shift
 lever is disclosed in U.S. Pat. No. 5,680,307 issued to Nabil M. Issa et
 al on Oct. 21, 1997, which is herein incorporated by reference.
 The foregoing disclosure of embodiments of the present invention has been
 presented for purposes of illustration and description. It is not intended
 to be exhaustive or to limit the invention to the precise forms disclosed.
 Many variations and modifications of the embodiments described herein will
 be obvious to one of ordinary skill in the art in light of the above
 disclosure. The scope of the invention is to be defined only by the claims
 appended hereto, and by their equivalents.