CROSS REFERENCE TO RELATED APPLICATIONS This application relates to the following simultaneously filed patent applications, which are incorporated by reference here within: U.S. Application No. 08/431,148 entitled "Multi-Functional Apparatus Employing An Electromagnetic Device" by H. Winston Maue and Eric J. Krupp; and U.S. Application Serial No.08/430,388 entitled "Multi-Functional Apparatus Employing an Intermittent Motion Mechanism" by William C. Zimmer and James Wayne Gibson.

BACKGROUND OF THE INVENTION

This invention relates generally to control systems for automobiles and specifically to a multiplexed control system for an automotive vehicle multi- functional apparatus.

Almost all automotive vehicles have a single or a pair of windshield wiper assemblies. These assemblies traditionally include rubber wiper blades mounted upon claw brackets. These claw brackets are pivotably attached to wiper arms mounted upon rotating shafts. These shafts are either directly driven by electric motors or driven by a single electric motor which actuates series or parallel-coupled four-bar linkage mechanisms. It is further known to provide a wiper system, in combination with a wash device, to clean headlamps for automotive vehicles. ft is also common to employ a window wiper assembly for cleaning rear windows of automotive vehicles. Typically, these types of rear window wiper assemblies include a wiper blade mounted upon a bracket which is coupled to a wiper arm. The wiper arm is attached to a wiper shaft rotatably driven in a cyclical oscillating manner by a helical gear. A reversible, fractional horsepower, dc electric motor serves to actuate the helical gear through an armature shaft-mounted worm gear enmeshed therewith. This type of rear window wiper arrangement is usually mounted upon a pivoting liftgate of a minivan, station wagon, sport-utility vehicle or the like. Examples of

conventional window wiper assemblies and motor mechanisms are disclosed with the following U.S. Patents: 4,893,039 entitled "Windshield Wiper Motor" which issued to Isii on January 9, 1990; 4,878,398 entitled "Driving Device for Window Wiper of Motor Vehicles" which issued to Heinrich on November 7, 1989; 4,336,482 entitled "Rear Window Wiper Motor Control" which issued to Goertler et al. on June 22, 1982; 4,259,624 entitled "Arrangement for Wiping a Vehicle Window" which issued to Seibicke on March 31 , 1981 ; 3,694,723 entitled "Motor Vehicle Windshield Wiper Having a Parking Position Outside the Wiper Area" which issued to Schneider et al. on September 26, 1972; and, 3,665,772 entitled "Windshield Wiper Motor Link Depressed Park Mechanism" which issued to Beard et al. on May 30, 1972. All of these patents are incorporated by reference herewithin.

Some conventional vehicles also provide a rear window release lock or latch, actuated by a solenoid, which can be unlocked to allow for upward pivotal movement of the rear window in relation to the otherwise stationary liftgate. In combination therewith, a separate liftgate lock is often mounted upon the liftgate door for fastening the liftgate to the body to prevent inadvertent pivotal opening. This liftgate lock is traditionally operated by manual key or handle rotation, or through a separate electric motor or solenoid

Additionally, separate motors and solenoids are required to actuate passenger door locks, an antenna retraction mechanism, headlamp cover retraction mechanisms, a fuel filler door lock and other similar functions. The traditional need for such a multiplicity of electromagnetic devices has increased the automotive vehicle weight and cost while further proving difficult to package within the often small spaces provided. This added weight is especially detrimental when the window wiper mechanism, rear window lock and liftgate lock, as well as their distinct respective electromagnetic devices, are all incorporated within the pivoting liftgate. Not only is the piece cost increased due to this multiplicity of electromagnetic devices, but the assembly cost, part number proliferation and handling costs, electrical wiring costs, objectional motor noise, and failure modes are increased.

rt is also known to provide multiplexed circuitry within automotive vehicles. Examples of such muftiplexed systems are disclosed within the following U.S. Patents: 4,578,591 entitled "Control Circuit for Automotive Accessory System" which issued to Floyd et al. on March 25, 1986; 4,534,025 entitled "Vehicle Multiplex System Having Protocol/Format for Secure Communication Transactions" which also issued to Floyd on August 6, 1985; 4,528,662 entitled "Multiplex Control System Having Enhanced Integrity" which also issued Floyd et al. on July 9, 1985; 4,492,904 entitled "Windshield Wiper System With Touch Control" which issued to Graham on January 8, 1985; 4,355,385 entitled "Multiplex Information Handling System" which issued to Hampshire et al. on October 19, 1982; and 4,293,947 entitled "Information Handling System" which issued to Brrttain on October 6, 1981 ; all of which are incorporated by reference herewrthin. While various of these patents having significantly improved the art, multiplexed circuits, in general, have not proven to be cost effect in automotive vehicle applications due to the often limited number of operable components and functions integrated into a multiplexed node. The incremental increase in microprocessor costs are rarely offset by the reduction in wiring costs. For instance, discretely wired, non-multiplexed wiring harnesses have always been used to electrically connect liftgate devices to the body wire harness. These conventional wire harnesses are costly, cumbersome to package, difficult and heavy for handling and installation, and inhibit easy pivoting of the liftgate door due to the wire harness stiffness. EΞxpensive and large electrical connectors are also required.

SUMMARY OF THE INVENTION In accordance with the present invention, the preferred embodiment of a control system for an automotive vehicle multi-functional apparatus employs an electronic control unit operably controlling a rear window wiper assembly. In another aspect of the present invention, an electronic control unit is operable as a multiplexed rear node for controlling a variety of liftgate devices and functions. In a further aspect of the present invention, an electronic control unit controls a single multi-functional electromagnetic device.

The multi-functional electromagnetic device uses intermittent motion mechanisms to selectively operate differing devices driven therefrom. A method of operating the electronic control unit of the present invention is also provided. The control system of the present invention is advantageous over conventional systems since the present invention combines many different functions into a single electronic control unit. Furthermore, the electronic control unit is programmable thereby allowing for relatively easy modifications and vehiclβ-to-vehicle and customer selected option differences without hardware changes. Moreover, a single electromagnetic device is controlled by the control system thereby further enhancing the synergistic effects of the present invention. For example, the electronic control unit replaces the traditional separate rear wiper motor, liftgate lock motor and rear window lock solenoid. Since an electronic control unit is required to operate the single electromagnetic device, it is cost effective to also use this electronic control unit as a multiplexed rear node. Accordingly, the present invention significantly reduces the piece cost, assembly cost, part proliferation and handling costs, and wiring costs as compared to non-multiplexed and multiple electromagnetic device constructions. Furthermore, the control system and multi-functional apparatus of the present invention significantly reduces weight and packaging space requirements while increasing the electrical and mechanical reliability of the affected systems. For instance, by multiplexing the present invention circuits, 14 conventional circuits and 8 conventional takeouts (i.e., splices or connections) can be deleted. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a front elevational view showing the preferred embodiment of a control system for an automotive vehicle multi-functional apparatus;

Figure 2 is a rear elevational view, with portions broken away therefrom, showing a first preferred embodiment multi-functional apparatus employed in the preferred embodiment control system of the present invention;

Figure 3a is a cross sectional view showing a second preferred embodiment multi-functional apparatus employed in the preferred embodiment control system of the present invention;

Figure 3b is a perspective view, with portions broken away therefrom, showing the second preferred embodiment multi-functional apparatus employed in the preferred embodiment control system of the present invention;

Figure 4 is a diagrammatic front view showing a motor feedback circuit disk employed in the preferred embodiment control system of the present invention;

Figures 5a-c are electrical schematic diagrams showing the preferred embodiment control system of the present invention;

Figure 6 is an electrical schematic diagram showing a portion of the automotive vehicle circuitry employing the preferred embodiment control system of the present invention;

Figure 7 is an electrical schematic diagram showing a motor portion of the preferred embodiment control system of the present invention;

Figure 8 is an electrical schematic diagram showing a center high mount stop lamp portion of the preferred embodiment control system of the present invention;

Figure 9 is an electrical schematic diagram showing a license lamp portion of the preferred embodiment control system of the present invention;

Figure 10 is an electrical schematic diagram showing a heated backlite portion of the preferred embodiment control system of the present invention; Figures 11 a-b are flow diagrams showing a main microprocessor program employed with the preferred embodiment control system of the present invention;

Figure 12 is a flow diagram showing a J1850 software subroutine of the preferred embodiment control system of the present invention;

Figures 13a-c are flow diagrams showing a motor software subroutine of the preferred embodiment control system of the present invention;

Figure 14 is a flow diagram showing a lamps software subroutine of the preferred embodiment control system of the present invention;

Figure 15 is a flow diagram showing a heated backlite software subroutine of the preferred embodiment control system of the present invention; and

Figures 16a-c are flow diagrams showing an inputs software subroutine of the preferred embodiment control system of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An automotive vehicle, such as a minivan or the like, has a rear liftgate door which can pivot about an upper pair of hinges coupled to the vehicle body structure. When the liftgate is pivoted to an open position, a cargo space is accessible from behind the vehicle. Such a liftgate is shown in Figure 1. Liftgate 31 has a rear window or backlite 33 pivotable between a closed position, substantially flush with the outer surface of liftgate 31 , to an open position about the upper hinges. A pair of pneumatic cylinders 35 act to push window 33 toward the open position when a lower portion of window 33 is released. A multi-functional apparatus 41 of the present invention is mounted upon an inner surtace of liftgate 31 and is operated by the preferred embodiment of a control system of the present invention. The majority of apparatus 41 is hidden by an interior trim panel (not shown). Apparatus 41 includes a central drive and power transmission unit 43, a window wiper assembly 45, a window release latch or lock 47 and a liftgate lock 49, all of which are mounted upon liftgate 31. (Examples of such locks (employing separate solenoids or motors, which would be removed in order to couple the lock mechanism for use with the present invention) are disclosed within the

following U.S. patents: 5,222,775 entitled "Power Operated Latch Device for Automotive Back Door" which issued to Kato on June 29, 1993; 4,422,522 entitled "Inertial Lock for Vehicle Door Latch" which issued to Slavin et al. on December 27, 1983; and, 3,917,330 entitled "Electric Lock Release" which issued to Quantz on November 4, 1975; all of which are incorporated by reference herewithin.

The construction of a first preferred embodiment central drive and power transmission unit 43 is shown in Figure 2. An electromagnetic device such as an electric motor 51 is of a conventional fractional horsepower, dc electromagnetic variety having a metallic motor housing within which are stationary permanent magnets, a rotatable armature with wire windings, a rotatable armature shaft joined to the armature, a commutator electrically connected to the wire windings and rotatable with the armature shaft, a brush card assembly and various electronic components, bushings and retainers. It will be apparent to those skilled in the art that other electric motor constructions can readily be substituted for that shown. A worm gear segment 53 is provided upon a portion of the armature shaft extending beyond the motor housing. A helical main gear 55 is enmeshed with worm gear segment 53. Furthermore, a drive pin 57 protrudes from a face of helical gear 55 for selectively engaging within a channel 59 of one of three rotatable intermittent motion mechanisms or cams 71 , 73 or 75. Cam 71 has a spur gear portion drivably enmeshed with a pinion gear 77 which, in turn, rotates a rear wiper shaft 79 coupled thereto by rivets, insert molding, a knurled press fit, et cetera. A liftgate door lock coupling assembly 135 (see Figure 1 ) couples movement of cam 73 to that of liftgate lock 49 (also see Figure 1). Similarly, rear window lock coupling assembly 141 (see Figure 1) mechanically couples movement of cam 75 to that of window release lock 47 (also see Figure 1).

A second preferred embodiment construction of central drive and power transmission unit 43 is illustrated in Figures 3a-b. A worm gear segment 155 of an armature shaft extends from an electromagnetic device such as an electric motor. A main helical gear 159 is enmeshed with worm gear segment 155. An electrically conductive feedback disk 181 is retained to an inside face

183 of helical gear 159 through ultrasonically rolled welding or insert molding. Feedback disk 181 is comprised of a set of copper alloy or brass alloy stamped contacts which are provided with differing conductive and nonconductive patterns depending on the specific positional ranges as is shown in Figure 4. Returning to Figures 3a-b, a selectively disengagable clutch mechanism 185 is comprised of a spring biased actuator shaft 187, a stationary collar 189 extending from a gear housing, and a rear window wiper shaft 191. Actuator shaft 187 has a set of splines slidably enmeshed with internal splines of helical gear 159. Actuator shaft 187 further has a cam follower 193 which selectively rides along a camming surface 195. A pair of helical fingers 197 projecting from actuator shaft 187 are disengagably coupled within a pair of matching receptacles 199 of wiper shaft 191. A pivotable wire lock linkage assembly 201 and a linearly slidable window release lock linkage 203 are selectively movable upon rotated direct contact with a spring tab mounted upon a rear face of helical gear 159.

Referring to Figures 1 , 5 and 6, an electronic control unit or microprocessor 251 is mounted upon a rigid printed circuit board mounted to central drive and power transmission unit 43. Microprocessor 251 is operatively configured as a liftgate mounted rear node electrically connected to a main body controller or microprocessor 253 in a multiplexed manner through a wire harness 255. A well known SAE J1850 multiplex (MUX) protocol is used to communicate between rear node 251 and body controller 253. An SAE J2178 multiplex message strategy and an SAE J2190 multiplex diagnostic standards are also employed within rear node 251. These three SAE standards are incorporated by reference herewithin. Wire harness 255 contains four battery power/ground wire circuits 261, passing through a junction box (JB) 263 located within an instrument panel and a power distribution center (PDC) 265 located within an engine compartment, and one or two MUX communication wire circuits 267. One MUX circuit 267 is preferably used if rear node 251 is the last node within the electrical system as is the type employed in the present invention. Furthermore, only three power/ground circuits 261 may alternately be used depending on the specific electrical architecture desired. Throughout

the circuit diagrams, "> >" is defined as a main harness electrical connector with "B" being defined as a body wiring harness, "L" being defined as a liftgate harness, "E" being defined as an engine compartment harness and "I" being defined as an instrument panel harness. Microprocessor 251 measures the rotational position of helical gear 55 (see Figure 4), and in turn, the electrical motor, through feedback disk 181 acting in conjunction with three electrical input contactors and a common ground contactor 323 riding therealong. By employing a monostropic code (i.e.: requiring only a single bit to change when the feedback disk passes from any positional range to an adjacent range) microprocessor 251 converts the feedback disk code pattern signal to a binary code for use within the motor subroutine as will be discussed in greater detail hereinafter. Circuit No. 1 of power/ground circuits 261 is a high current battery input to a normally closed relay 331. Microprocessor 251 controls relay 331 for supplying current to a conductive heated backlite element grid 333, made of known silver ceramic paste silkscreened upon backlite or rear window 33, through output buffers 335. The heated backlite portion of the control system is also shown in Figure 10. Returning to Figures 1, 5 and 6, Circuit No. 2 of power/ground circuits 261 supplies current through a reverse battery protection diode 341 , a parallel set of resistors 343, a battery filtering bank of capacitors 345 to the microprocessor 251 and output buffers 335. In addition, Circuit No. 2 supplies high current to a reversible H-bridge configuration, normally closed relay 346 for supplying current to the multi-functional motor via leads 347. Main body controller 253 sends a heated backlite energization signal to rear node 251 upon receiving an energization input from a heated backlite switch 399 actuable by the vehicle occupant. A load dump transient protection varistor 351 is provided between power Circuit No. 2 and the logic and analog ground circuits. The multi¬ functional motor portion of the present invention control system is also shown in Figure 7. Returning again to Figures 1 , 5 and 6, a set of liftgate mounted input switches 361 and wiper motor position inputs 323 operably provide input signals to microprocessor 251 subject to sets of pull up resistors 363 and 365, filtering sets of resistors 367 and 369, and filtering sets of capacitors 371 , 373,

375 and 377. Liftgate inputs 361 include a liftgate key cylinder disarm switch 451 , a liftgate ajar switch 453, rear window or liftglass ajar switch 455, liftglass/window unlock and release button switch 457, and a liftgate lock/limit position switch 459. Microprocessor 251 preferably uses a Motorola MC68HC05V6 (or alternately MC68HC05V7) chip having an on-chip 5 volt power regulator, watchdog system, ROM, RAM and erasable EEPROM. A resonator clock 381 is also provided. The 68HC05V7 Motorola specification, revision 1.0 of August 12, 1994, is incorporated by reference herewithin. Referring to Figures 1 , 5, 8 and 9, microprocessor 251 is selectively operable to control energization and illumination of center high mount stop lamp (CHMSL) bulbs 401 via circuits passing through a high side, solid state switch 403. CHMSL bulbs 401 are illuminated when rear node microprocessor 251 receives a multiplexed signal from body controller 253 in response to actuation of a brake pedal operated switch 405. In the figures, the dashed circuit represents a shared common circuit. Similarly, rear node microprocessor 251 selectively operates to energize and illuminate a license plate lamp having a pair of light bulbs 411 , through switch 403 and the associated circuits. Main body controller 253 causes rear node microprocessor 251 to illuminate license lamp bulbs 411 in response to vehicle occupant actuation of a head lamp switch 421 in combination with energization of a park lamp relay 423 within junction box 263. A variety of interior and exterior reading, courtesy, brake, turn signal and other lamps may also be actuated through rear node microprocessor 251. The MUX communication lines 267 are further provided with a set of resistors 391 for providing an integrity check, and a MUX bus loading and filtering inductive component 393. Microprocessor 251 further has means to debounce, or read and verify the stability of an input signal for a given time interval. The operation and programmable software logic used to operate the preferred embodiment control system of the present invention will now be described in detail. The rear node microprocessor of the preferred

embodiment control system of the present invention is operated by a main software program as shown in the flow diagrams of Figures 11a and b. When power is applied through the ignition switch, the rear node microprocessor first tests and clears the random access memory (RAM), tests the read only memory (ROM), performs a check sum function, initializes the J1850 hardware and clears the input and output ports while setting up the input and output direction. The rear node microprocessor then enables the timer and interrupts, enters a low power stop mode and then determines whether external interrupts are detected. If external interrupts are detected, the rear node microprocessor initializes the system timer, enables the input task and enables the J1850 task. The rear node microprocessor then determines if it needs to run the J1850 subroutine; if yes, the J1850 subroutine is run. If no, the rear node microprocessor then determines if it needs to run the electric motor subroutine; if yes, the electric motor subroutine is run. If no, the rear node microprocessor determines if it needs to run the lamps subroutine; if yes, the lamps subroutine is run. If no, the rear node microprocessor then determines if it needs to run the heated backlite subroutine; if yes, the heated backlite subroutine is run. If no, the rear node microprocessor determines if it needs to run the inputs subroutine; if yes, the rear node microprocessor runs the inputs subroutine. If no, or upon completion of the inputs subroutine, the rear node microprocessor returns to determining the need to run the J1850 subroutine.

The logic flow of the J1850 subroutine is illustrated in Figure 12.

The rear node microprocessor must first determine if any J1850 messages are being received from the main body controller; if yes, the rear node microprocessor indicates and responds to all new messages. If no, or upon completion of the indicating and responding step, the rear node microprocessor must then determine if any J1850 messages are to be transmitted back to the main body controller; if no, the rear node microprocessor skips to a re-enable routine step. If yes, the rear node microprocessor must determine if the transmission buffer is empty; if no, the rear node microprocessor skips to the re-enable routine step. If yes, the rear node microprocessor loads the message to be transmitted into a transmission

buffer and then transmits the message back to the main body controller through the J1850 circuits within the wire harness. Next, the rear node microprocessor re-enables the J1850 subroutine in five milliseconds. The rear node microprocessor software then returns to the main program. Referring to Figures 13a-c, the multi-functional electric motor subroutine is accessed by the rear node microprocessor. The rear node microprocessor must first determine if the motor position is invalid; if yes, the motor is turned off or de-energized and the software returns to the main program. If no, the rear node microprocessor must determine if the motor position change is out of operational sequence; if yes, the motor is turned off and the software returns to the main program. If no, the microprocessor must determine if the motor is in a stalled condition due to overheating, excessive loading due to ice build up, et cetera; if yes, the motor is turned off and the software returns to the main program. If no, the rear node microprocessor must determine if the liftgate or rear window are ajar or partially open; if yes, the rear node microprocessor determines if the motor is in the window wiper or window washing operational mode. If the motor is determined to be in the wiper/wash mode then the rear node microprocessor sends the motor to a wiper park position. Upon completion of sending the motor to the wiper park position if the ajar or wiper/wash mode decisions are no, then the rear node microprocessor must determine if it has received a liftgate lock or unlock actuation input message; if yes, the rear node microprocessor must determine if the electric motor is in the window wiper or window washing operational mode; if yes, the rear node microprocessor will send the motor to the wiper park position and subsequently send the motor to a rear window unlocking and release position. This allows the pneumatic cylinders to upwardly pivot the rear window without fear of interference of the window wiper assembly. If the microprocessor determines that the electric motor is not in the wiper/wash mode, then it skips directly to the step sending the motor to the liftglass unlocking position. The rear node microprocessor must then determine if it has then received a window wiper or window washing activation or on input message from the main body controller; if yes, it must then be determined if a

liftgate or rear window ajar switch signal is being received (since the vehicle occupant could have manually closed, thereby locking, the rear window). If no ajar signal is being received, the rear node microprocessor causes the electric motor to oscillate the wiper assembly in a wiping or washing mode. If a wiper/wash on message has not been received, the liftgate or rear window ajar signal is being received, or upon completion of the wiper/wash mode, the rear node microprocessor must then determine if a wiper/wash off input message is being received from the main body controller; if yes, the rear node microprocessor sends the motor to the wiper park position. Upon completion of that step or upon determining no to the wiper/wash off message decision, the software returns to the main program.

As shown in Figure 14, the lamps subroutine requires the rear node microprocessor to first determine whether a new license plate lamp input message has been received from the main body controller; if yes, it must then be determined if the message is to turn the lamp on or off. If an on message is present, the rear node microprocessor will cause the license plate lamp to be turned on or illuminated. If an off message is being received, the rear node microprocessor will cause the license plate lamp to be turned off or de- energized. Subsequently, the rear node microprocessor must determine if the CHMSL lamp message is being received from the main body controller; if yes, it must then be determined if the message is to turn the CHMSL lamp on or off. If an on message is being received, the rear node microprocessor will cause the CHMSL bulbs to become illuminated. If an off message is being received, the rear node microprocessor will cause the CHMSL bulbs to be turned off or de-energized. The software then returns to the main program.

The heated backlite subroutine is shown in Figure 15. The rear node microprocessor must first determine if a new heated backlite operational message is being received from the main body controller; if yes, the rear node microprocessor must then determine if the message received is to turn the backlite heating elements on or off. If an on message is being received, the microprocessor causes the backlite heating elements to be energized, enables a heated backlite timer and then returns back to this subroutine in one second.

If the message being received is to turn the heated backlite off then the rear node microprocessor disables the heated backlite timer and then turns off and causes de-energization of the heated backlite element. If a new heated backlite message is not being received then the rear node microprocessor must determine if the heated backlight elements are already on and energized; if yes, the microprocessor determines if the timer has expired. If the timer has expired then the rear node microprocessor turns off the heated backlight elements. If the heated backlite timer has not expired then the software returns to this subroutine in one second. Upon completion of all these branched steps, the software returns to the main program.

Finally, the inputs subroutine is shown in Figures 16a-c. The rear node microprocessor software first debounces the liftgate inputs and then must decide if any changes are present with regard to the liftgate inputs. If yes, the rear node microprocessor must determine if the liftgate input has changed to an active or signal generating state; if yes, the motor subroutine is enabled. If no, the rear node microprocessor must determine if the ajar input has changed to an active state; if yes, the motor subroutine is enabled and then the liftgate ajar input message is queued or accessed. The rear node microprocessor must next determine if the liftgate cylinder lock switch input has changed to an active state; if yes, the motor subroutine is enabled. A no determination for any of these previously discussed input decisions leads to a debouncing step for the motor position inputs. The rear node microprocessor determines if any changes regarding the motor position inputs are being received; if yes, the motor subroutine is enabled. The rear node microprocessor must then determine if a new wiper or wash J1850 message is being received; if yes, the motor subroutine is enabled and the software clears a new message flag. A new liftgate lock/unlock J1850 input message determination must be made; if yes, the motor subroutine is enabled and a new message flag is cleared. Subsequently, the rear node microprocessor decides if a new rear window unlock and release J1850 input message is being received; if yes, the motor subroutine is enabled and a new message flag is cleared. The rear node microprocessor must then determine if a new license lamp or CHMSL J1850

input message is being received; if yes, the lamp subroutine is enabled and a new message flag is cleared. Lastly, the rear node microprocessor then determines if a new heated backlite J1850 input message is being received; if yes, the heated backlite subroutine is enabled and a new message flag is cleared. This inputs subroutine is re-enabled in ten milliseconds and the software returns to the main program until the rear node microprocessor is de- energized.

While the preferred embodiment of this control system and multi¬ functional apparatus have been disclosed, it will be appreciated that various modifications may be made without departing from the present invention. It must be appreciated that in alternate embodiments, the feedback disk can be replaced or supplemented by other feedback means coupled to a gear or motor, such as optical sensors, magnetic sensors, limit switches, potentiometers, proximity sensors, rotation sensors, torque sensors, deposit metal traces, printed circuit boards, conductive ink traces, et cetera. FETs and bipolar components can further be used to replace the disclosed microprocessor. It will further be appreciated that a variety of other multiplexed or non-multiplexed, microprocessor or analog circuitry may be used to control the apparatus of the present invention. A solenoid, electromagnet or other electromagnetic devices may also be used in place of the previously described electric motor. Furthermore, additional spur gears, pinion gears, sector gears, planetary gears, jack screws, sprockets and chains, pulleys and belts, cables or other force transmitting means may be employed to couple between the electromagnetic device, rotatable member, clutch mechanism, intermittent motion mechanisms or locks. Moreover, a multiple gear transmission, linkage, belt or cable system can alternately couple a wiper assembly to the wiper shaft. The clutch mechanism can also be carried out in a variety of other constructions such as with Belleville springs, diaphragm springs, friction plates, sector gears, linkages or the like. The intermittent motion mechanisms may also be accomplished by employing other known intermittent motion mechanisms such as Geneva mechanisms, starwheel mechanisms, intermittent gearing, escapements, ratchet mechanisms or other known selectively actuable

devices. The multi-functional apparatus of the present invention can further be employed for windshield wipers, side door locks or other automotive vehicle and non-automotive vehicle applications. While various materials, electronic components, software flow diagrams, circuits and force transmitting members have been disclosed, a variety of other such materials, electronic components, software flow diagrams, circuits and force transmitting devices may be used. It is intended by the following claims to cover these and any other departures from the disclosed embodiments which fall within the true spirit of this invention.