Abstract:
Hydraulically actuated aerial lift units for trucks typically have a primary hydraulic pump system driven by the vehicle&#39;s engine or by an electric motor. An actuation system accessible to a worker suspended by the aerial lift unit allows the worker to cycle the vehicle&#39;s engine on and off and, on vehicles so equipped, activate the backup motor for lowering the aerial lift unit.

Description:
REFERENCE TO RELATED APPLICATION 
     This application claims priority from provisional application Ser. No. 60/477,908 filed Jun. 12, 2003. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The invention relates to power take off systems for utility vehicles and more particularly to a system providing remote starting and stopping of the vehicle and for control of an emergency back up motor to the power take off system. 
     2. Description of the Problem 
     Utility vehicles are often advantageously supplied with auxiliary equipment the operation of which is supported by the vehicle. Such auxiliary equipment can include hydraulically powered, aerial lift buckets that are often used for the repair of electrical power distribution lines. Typically, a hydraulic lift platform will be driven by a pump which is in turn driven by the vehicle&#39;s engine. In some applications, a back up prime mover, e.g. an electrical motor, is provided for the pump. A bucket at the end of the aerial lift system is electrically isolated to allow the worker to work on power lines which are still hot. 
     Trucks may come equipped with controls to allow a worker supported in the bucket to remotely shut off and turn on the vehicle&#39;s engine and to remotely raise and lower the lift. To avoid providing a conductive electrical path between the bucket and the truck, the controls located in and around the bucket for the operator&#39;s use are usually pneumatic. An air line is connected between the bucket, where a plunger-actuated piston is positioned, and a pneumatic, pressure actuated, electrical switch on the truck. To avoid expense a minimal number of pneumatic lines is provided. A problem addressed by the invention is providing a single, pneumatic, pressure actuated electrical switch which can be used to both start and stop a truck&#39;s engine, and in some applications, allow activation of a back up hydraulic pump in case of engine failure. Complicating the effort to construct such a device is the susceptibility of vehicle electronics to resetting during engine starting due to voltage fluctuations. 
     Industry standards specify that the bucket control for an aerial lift truck having an emergency or back up pump shall: (1) if the engine is running and the remote switch is closed (regardless of the duration for which it is held closed), shut down the engine; (2) if the remote switch is kept depressed for more than 3 seconds following a remote engine stop, cause the emergency or back up pump to operate and to continue to operate for as long as the switch is held closed; (3) if the remote switch is cycled following a remote stop or following the operation of the emergency pump, cause the engine to crank for the duration of the switch closure; and (4) if the engine does not start after cranking, respond to cycling the remote switch by causing the emergency pump to operate for as long as the remote switch is depressed. 
     Contemporary vehicles are commonly equipped with an electrical systems controller/body computer (ESC) and a controller area network allowing data transfer between the ESC and other controllers, including an engine controller and a transmission controller. These systems are built in conformance with the Society of Automotive Engineers&#39; J1939 standard. Remote engine and bucket position control must be implemented in a way that cranking and shut down of the engine is effected only by closure of a hard-wired, ground side switch. This remote switch must be designed in the system hardware and be independent of the ESC&#39;s software. The hardware architecture cannot depend upon the ESC remaining active during engine cranking and must continue to function even if the ESC temporarily fails and reinitializes due to transient low voltage. 
     The status of the ESC cannot be allowed to interfere with normal starting and stopping of the engine using the standard four-position key ignition switch. It must remain possible to crank the engine even when the vehicle is latched in the remote start mode. This allows ground personnel to start the engine and engage PTO operation to lower a boom should the operator be disabled. It is permissible to allow momentary cycling of the key ignition switch to cancel remote stop mode. The system shall prevent engine cranking in response to closure of the remote switch if the hood is open. The hood disable feature must also be independently operable without reference to ESC status. However, the backup pump motor must be operable with the hood open. 
     The backup motor and solenoid should not be operated for any duration of time, or briefly cycled on and off, unless the conditions for emergency operation have been met. The backup motor brushes and solenoid contact life may be compromised by repeated, brief duration operation at high surge current levels. Remote switch operation should not result in application of any current to the backup motor and solenoid unless and until its operation is necessary. 
     The system shall permit the engine to crank only so long as the remote switch is closed. Once the remote switch opens, cranking should immediately stop, allowing only for some delay where the remote switch is pneumatically actuated. The system shall not allow the engine to crank unless the parking brake is set. This requirement can be met by modification of ESC software. The system shall not allow remote engine shut down unless a J1939 compliant engine RPM message is present on the vehicle databus from an engine controller. This requirement prevents stranding an operator in a boom since the engine will not crank remotely if an engine RPM message is not present. 
     SUMMARY OF THE INVENTION 
     According to the invention there is provided a motor vehicle having a remote switch by which the vehicle&#39;s engine may be shut down and restarted. In some applications the same switch may be used to engage a backup electric motor energized from the vehicle&#39;s battery as a substitute prime mover for a power take off apparatus installed on the vehicle. The invention provides a vehicle engine ignition control system having a starter solenoid and motor and engine control electronics. A multiple position ignition switch provides energization to the ignition control system in response to positioning of a key switch, as is conventional. The ignition switch has two output terminals which assume energized states in response to the positioning of the key switch. A first output is energized when the key switch in placed in a start position. A second output is energized when the key switch is in either the ignition position or the start position and may be energized when the key switch is in an accessory position. A remote switch is located on the vehicle away from the multiple position ignition switch, typically in a bucket suspended by an aerial boom. The remote switch provides a connection to ground when closed. An electrical systems controller communicates with the engine control electronics and is coupled to the remote switch to be responsive to closure of the remote switch in accordance with its programming. Responses include providing various enable signals and/or ground connections enabling operation of selected portions of the ignition control system. A remote start relay is coupled to respond to a remote start energization signal sourced by the electrical systems controller if it occurs concurrently with closure of the remote start switch. The remote start relay provides an activation signal on an output which is applied to a starter relay. The starter relay responds to the activation signal by providing activation energization to the starter solenoid and motor. 
     Remote stop of the engine is provided by control of a chassis ignition relay, which couples an ignition signal (Ign) from the ignition switch to an engine controller. A remote switch state detection relay is coupled to the remote switch and to-the second output of the multiposition ignition switch and is responsive to the concurrent occurrence of an energization signal on the second output of the multiposition ignition switch and closure of the remote switch to generate a remote stop energization signal. The electrical systems controller is further responsive to closure of the remote switch and to indication that the engine is operating (by reading an engine RPM signal from the engine controller) for providing a ground connection through an input. A remote stop relay provides coupling of energization from the multiple position ignition switch to the chassis ignition relay. The chassis ignition relay is connected to the remote switch state detection relay to receive the remote stop relay energization signal and is further connected to the input of the controller, the remote stop relay being responsive to the remote stop energization signal and grounding of the ground side of its energization coil through the controller input for interrupting energization of the chassis ignition relay and thereby cutting the Ign signal to the engine controller, resulting in interruption of operation of the engine. 
     Where a vehicle is equipped with backup prime mover for a vehicle power take off (PTO) apparatus, the ignition system further includes a backup motor and solenoid connected to the vehicle electrical power source. A backup motor inhibit relay is connected across the power connection to the backup motor and solenoid to prevent any undesired operation of the motor, however brief. A backup motor relay is coupled to receive energization from the remote start relay and is further coupled to the remote switch to be responsive to concurrent closure of the remote switch and application of the energization signal from the remote start relay for coupling energization signal from the remote start relay to the backup motor inhibit relay as an input. Finally the electrical systems controller provides a connection to ground on an inhibit input in response to the key switch being in the ignition position and engine cranking having been attempted and failed. 
     Additional effects, features and advantages will be apparent in the written description that follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a simplified illustration of a truck mounted aerial lift assembly for locating an operator in various raised positions. 
     FIG. 2 is a high level schematic of a vehicle electrical and hydraulic control system incorporating the invention for the truck of FIG.  1 . 
     FIGS. 3-10 are a series of circuit schematics of a remote ignition control system in accordance with two embodiments of the invention. 
     FIGS. 11-12 are high-level flow charts of programs executed by a system electronics controller in implementing aspects of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings, and particularly to FIG. 1, an example of a mobile aerial lift truck  1  is illustrated in simplified presentation for clarity of illustration. The mobile aerial lift truck  1  includes an aerial lift unit  2  mounted to a bed on the back portion of the truck. The aerial lift unit  2  includes a lower boom  3  and an upper boom  4  pivotally interconnected to each other and to the truck bed through support  6  and rotatable support bracket  7 . A bucket/basket  5  is shown secured to the outer end of the upper boom  4  within which the operating personnel are located during the lifting to and locating within a selected work area in accordance with known practice. Basket  5  is typically pivotally attached to the out end of the boom  4  to maintain a horizontal (level) orientation at all times. The aerial lift unit  2  is mounted to the truck bed through support  6 . A rotatable support bracket  7  is secured to the support  6  and projects upwardly. The lower boom  3  is pivotally connected as at pivot  8 , to the rotatable support bracket  7 . A lifting lower boom cylinder unit  9  is interconnected between bracket  7  and the lower boom  3 . In the illustrated embodiment, a pivot connection  10  connects the lower boom cylinder  11  of unit  9  to the bracket  7 . A cylinder md  12  extends from the cylinder  11  and is pivotally connected to the boom  3  through a pivot  13 . Lower boom cylinder unit  9  is connected to either of two hydraulic supplies of a suitable hydraulic fluid, which allow the assembly to be lifted and lowered as desired. 
     The outer end of the lower boom  3  is interconnected to the lower and pivot end of the upper boom  4 . A pivot  116  interconnects the outer end of the lower boom  3  to the pivot end of upper boom. An upper boom compensating cylinder unit or assembly  117  is connected between the lower boom  3  and the upper boom for pivoting the upper boom about pivot  116  for positioning of the upper boom relative to the lower boom. The upper boom/compensating cylinder unit  117  is constructed to permit independent movement of the upper boom  4  relative to boom  3  and to provide a compensating motion between the booms to maintain the upper boom raising with the lower boom and is similarly connected to the sources of pressurized hydraulic fluid as further developed below. Conventionally, aerial lift unit  2  requires positive hydraulic pressure both to be lifted or to be lowered. Bucket  5  includes a plunger moving a piston in an air line. The air line runs from bucket  5  to a point on truck  1  where a remote switch, as described below, is located. 
     FIG. 2 is a block diagram schematic illustrating electronic control of a truck  1 , based on controller area network technology and an electrical systems controller/body computer (ESC)  24 . Collectively, bus/data link  18  and the various nodes (generally the various vocational controllers described below) to which it is attached form the controller area network (CAN), which conforms to the SAE J1939 standard. Controller area networks are networks which do not have destination addresses for nodes attached to the networks, but rather provide for transmission of data in packets, identified as to the source, message type and priority. The nodes are programmed as to whether to respond to a packet based on one or more of three identifiers. Many message types are predefined by the SAE J1939 standard. The SAE J1939 standard: allows the definition of proprietary message types which in structure conform to the standard. 
     Active vehicle components are typically controlled by one of a group of autonomous, vocational controllers. These vocational controllers include ESC  24 , an engine controller  20 , a electrical gauge controller  14 , a transmission controller  16 , an anti-lock brake system controller  22 , and a remote power take off controller  57 . ESC  24  and engine controller  20  are of primary interest to the present invention. Transmission controller  16  is provided with vehicles equipped with automatic transmissions and generates a signal indicating whether the vehicle&#39;s drive line is engaged or not. It is preferred at the time this application is being written that application of the invention be limited to vehicles equipped with automatic transmissions due to the lack of a indicator on vehicles equipped with standard transmissions as to whether the vehicle drive line is disengaged. Should such an indicator be made available the invention can be used on vehicles equipped with standard transmissions. Engine controller  30  provides an engine RPM signal, which is required for implementing certain routines in ESC  24 . The engine controller  20  also receives certain signals implicated in engine operation. ESC  24 , through discrete input ports  50  and output ports  52 , provides selective enable signals and ground connections, and detects the state of a remote switch used for remotely starling and stopping the vehicle&#39;s engine. 
     The hydraulic lift unit  58  which supports operation of an aerial lift unit  2  is primarily powered by a conventional PTO hydraulic pump  60  which is usually driven by engine  30 . Backup to engine  30  for powering hydraulic pump  60  is provided by a backup solenoid and motor  54 , energized from vehicle battery  21 . Energization of backup solenoid and motor  54  is controlled in part by programming of ESC  24  and control signals issued by it through discrete outputs  52  coupled into the starter system  100  and a pump inhibit relay  46 . Energization for backup solenoid and motor  54  is supplied by battery  21  as controlled by a pump relay  36  and the pump inhibit relay  46 . ESC  24  also controls remote starting and stopping of engine  30  by control signals provided to starter system  100  which in turn provides control signals to a starter solenoid and motor  59  and engine controller  20 . Battery  21  charge is maintained by an engine  30  driven charging system  47 . ESC  24  also monitors the position of a parking brake and a PTO on/off switch. PTO on/off switch is located in a multiplexed switch pack  43 , monitored on the J1708 switch data link  49 . The parking brake is a discrete switch input  50 . 
     Referring to FIGS. 3-7, a preferred embodiment of the starter system  100  as applied to a vehicle not having a backup hydraulic pump motor is illustrated. Starter system  100  provides for starting and stopping an internal combustion engine  30  from either inside a vehicle cab using an ignition switch  102  or from a remote point on the vehicle using a remote switch  110 . Remote switch  110  is a ground side, momentary contact switch with a default open state. Remote switch  110  is pneumatically actuated using a plunger  117  into an air line  111 . Ignition switch  102 , as is conventional, has four position: (1) accessory/Acc; (2) off; (3) ignition; and (4) start. Ignition switch  102  has first and second mechanically linked switches  106  and  108 . Switch  106  has an output connected to the start contact of the switch. For switch  108  the ignition and start position are tied together for output  115 . Ignition and Accessory/Acc positions are tied together when the key switch is either of these positions. Accessory/Acc is a discrete input to the ESC  24 . Acc has +12V anytime the key is in the accessory or ignition positions. Accessory drops out with the key switch in the crank position, which permits the invention to detect that the key switch is in the crank position during a remote stop period, such as the case where someone in the cab cranks the engine should the operator in the boom not be able to start the engine remotely (e.g. when the operator is unable to press the remote button. Switch  108 , as described below, allows for remote stopping and starting of an engine using remote switch  110 . Ignition switch  102  is key actuated and is energized through a 5 amp fuse  104  from battery  21 . For clarity of presentation, the off and ignition contacts for switch  106  are shown as floating, their operation not effecting the invention. The accessory contact of switch  106  provides power as an input to the ESC  24 . 
     Remote switch  110 , ignition switch  102  and the various relays used in implementing starter system  100  interact with programmable controllers which communicate with one another over the J1939 datalink  18 . ESC  24  and engine controller  20  monitor the state of various signals and provide enabling signals (including signals characterized by a ground connection through the controller) which implement aspects of the invention. Transmission controller  16  provides a driveline engagement indication signal used by engine controller  20  which inhibits cranking should the transmission engagement signal indicate the transmission (not shown) is in neutral or park. Some operations of starter system  100  can however be invoked notwithstanding temporary failure of the programmable controllers. ESC  24  is illustrated sectioned into two parts, one associated with electrical connections outside of a vehicle cab and a second section inside the vehicle cab. ESC  24  is usually one device and the division is simply for convenience of illustration. Adapting starter system  100  for remote operation must be done in a way that does not change normal operation of a vehicle. Accordingly, switch  106 , when moved to the start position, supplies power to a sense input (PIN  86 ) of starter relay  112 . This causes starter relay  144  to close thus supplying power from battery  21  through fuse  144  to the output associated with PIN  87  of the starter relay and from there to a starter solenoid and motor  59 . Engine controller  20  provides a ground to PIN  85  of starter relay  112  through a transistor switch  126  which is biased into conductivity in response to a gate signal provided by microprocessor  124 . 
     Remote operation is possible when ignition switch  102  is placed in the “ignition position”. This places both of switches  106  and  108  in the ignition position, supplying power to node  115  which is tied to the second output of ignition switch  102 . Remote operation is invoked by closing momentary contact remote switch  110 , the effect of which is to connect to ground node  113 , which is normally biased high by ESC  24  from a sensor input  130 . The closure of remote switch  110  is detected by ESC  24  through sensor input  130 . The closure of remote switch  110  also grounds the ground side contact for the sense coil of a remote start relay  138  and the ground side contact for the sense coil of a remote switch state detect relay  132 . Assuming initially that engine  30  is running, the closure of remote switch  110  results in engine  30  being shut down. Since switch  108  is in the ignition position power flows from node  115  to the high side contact for the sense coil for remote switch state detect relay  132 , and the relay closes, supplying power from ignition switch  102  through remote switch state detect relay  132  to the high side sense input of remote stop relay  114 . 
     Upon detection of closure of remote switch  110  ESC  24  determines if the conditions for remote stop are present, e.g. (1) parking brake set, (2) Engine RPM signal non-zero, etc. It all the conditions are met, ESC  24  will provide a ground connection through transistor  132  (an RD 15  low side driver) to the low side contact for the sense coil of remote stop relay  114 , resulting in the relay opening and the transfer of power through the remote stop relay being interrupted. When remote stop relay  114  opens, three ignition relays  116 ,  118  and  120  are all interrupted, with the result that power to all ignition powered features of the vehicle are interrupted. Chassis ignition relay  116  provides an ignition signal (Ign) via fuse  122  to engine controller  20  and microprocessor  124 . Engine controller  20  in turn carries out a shut down of engine  30 . Power is also interrupted to transmission controller  16 . 
     When the user releases remote switch  110 , DIN  19  on ESC  24  detects an increase in voltage at node  113  indicating to ESC  24  that the remote switch has opened. Remote switch state detect relay  132  is deenergized due to loss of a connection to ground on the low side of the switch state detect relays sense coil. Remote stop relay  114  remains energized (i.e. latched) because the high side of the remote stop relay sense coil is bed to DIN  87  of the relay and ESC  24  continues to provide a ground connection to the low side of the remote stop relay&#39;s coil. 
     Remote start is explained with reference to FIG.  4 . Again a user causes remote switch  110  to close and holds the remote switch down. Engine  30  cranks for as long as remote switch  110  is held closed. Upon closure of remote switch  110  node  113  drops to ground, an event which is detected by sensor  130  (DIN  19 ) of ESC  24 . The voltage drop causes remote switch state detect relay  132  to trip to a closed state, an operation which has no other effect on circuit operation. In response to the fall in voltage ESC  24  determines if the conditions for remote start are met. If the conditions are met, ESC  24  removes the gate voltage from transistor  134  cutting off conduction through the device. At this point the remote stop relay  114  deenergizes, reconnecting the high sides of the energization coils for the three ignition relays  116 ,  118  and  120 , to power from multiple position ignition switch  102 . The low side contacts for the sense coils for all three of the ignition relays  116 ,  118  and  120  are connected permanently to chassis ground so all three relays are automatically reenergized. The signal Ign to engine controller  20  is thus restored and transistor  126  is energized to connect the ground side of the energization coil of starter relay  112  to ground. Ign also indicates to the engine controller  20  that other ignition management functions are to be implemented. 
     ESC  24  must carry out certain actions to enable an engine restart in response to closure of remote switch  110 . The response to the detected voltage drop on node  113  includes ESC  24  driving output  136  high. With output  136  high and node  113  low, a voltage difference appears across the contacts of the sense coil for remote start relay  138  and the relay becomes energized. Provided the vehicle hood is closed (thus dosing a hood safety switch  142 ), power will be coupled through remote start relay  138  to the sense coil high side input (DIN  86 ) of starter relay  112  from node  115  with the key switch of the multiple position ignition switch  102  in the ignition (Ign) position. With starter relay  112  energized, energy is coupled through the starter relay from battery  21  to starter solenoid and motor  59  to initiate cranking. 
     High surge currents delivered to starter solenoid and motor  59  may cause a system voltage drop which may result in ESC  24  resetting. If this occurs transistor  134  remains in a non-conductive state which is desired. However, output  136  can fail. Accordingly, it is desirable to provide a means of latching remote start relay  138  in an energized state for cranking, since cranking will cease if remote start relay  138  deenergizes in response to loss of the signal from output  136 . See FIG.  6 . To effect latching of remote start relay  138  a diode  140  is provided oriented to conduct electricity from DIN  87  (the normally open contact) of remote start relay  138  to the high side contact of the energization coil for the relay. Once remote start relay  138  is energized, and for as long as remote switch  110  is closed, the relay will remain latched by way of a forward biased diode  140 . This of course requires the ignition switch  102  remain in the Ign or St position. If Ignition switch  102  is moved to the OFF position, it will of course deprive the output DIN  87  of power and remote start relay  138  will be deengergized. Release of remote switch  110  deprives the ground side contact of the energization coil of the remote start relay of a ground connection also resulting in deenergization of the relay. See FIG.  7 . 
     A diode  140  is used instead of a wire connection to provide a latch mechanism for remote start relay  138 . Were a wire used to connect the contacts of remote start relay  138 , anytime a high signal appeared on output  136  of ESC  24  the engine would crank. Since ESC  24  is subject to reprogramming and field maintenance the possibility that the device could be reprogrammed or rewired cannot be discounted. The engine crank inhibit low side driver (sensor input  130 ) is a relatively low impedance path to ground from node  113  when the transmission Is in neutral. It could function to pull down node  113  enough to be detected as closed remote switch. 
     Referring to FIGS. 8-10 a second embodiment of the invention incorporating an emergency pump motor and solenoid  54  is described. The remote start/stop circuit  100  of FIGS. 3-7 is unchanged except for the addition of the emergency motor and associated control relays. As with the remote start operation, operation of the emergency motor is to be invoked using remote switch  110 . An additional connection to ESC  24  is also provided to allow ESC  24  a certain degree of control over remote operation of emergency pump motor and solenoid  54  although the circuit provides for failsafe operation of the emergency pump motor should ESC  24  fail. 
     Normally the operation of emergency pump motor and solenoid  54  is inhibited by ESC  24 . This is effected by ESC  24  energizing transistor  146  to provide a pump inhibit signal (a ground contact) to the low side contact of the energization coil of pump inhibit relay  46 . The high side contact of the energization coil of pump inhibit relay  46  is connected to node  115 . As a result, pump inhibit relay is energized and no activation signal can flow from the relay to emergency pump and solenoid  54 . See FIG.  8 . 
     Emergency pump operation following a remote stop occurs when a user/operator keeps remote switch  110  depressed after a remote engine shut down. Remote start relay  138  is not energized, so ignition voltage is supplied from multiple position ignition switch  102  via node  115  to the high side sense coil contact of pump relay  36  energization coil and to the power input contact of the pump relay, the two contacts being in common. See FIG.  9 . With the ground side contact of the energization coil of pump relay  36  at ground, the response of pump relay  36  is to energize supplying power to DIN  30  (common terminal) of pump inhibit relay  54 . 
     ESC  24  times the duration of closure of remote switch  110  and when three seconds have expired deenergizes transistor  146  depriving a connection to ground for the ground side contact of the energization coil of pump inhibit relay  46 . Pump inhibit relay  46  deenergizes connecting the common terminal of the relay to output DIN  87 A and thereby supplying an activation signal to emergency pump motor and solenoid  54 . See FIG.  10 . The deenergized pump inhibit relay  46  supplies ignition voltage to the emergency pump motor solenoid resulting in energization of the emergency pump motor. Emergency pump motor and solenoid  54  operates as long as remote switch  110  is held closed. Opening remote switch  110  causes pump relay  36  to deenergize, interrupting the signal to the common terminal of pump inhibit relay  46  which in turn deenergizes depriving emergency pump motor and solenoid  54  of an activation signal. In addition, when remote switch  110  is released the voltage on node  113  increases, which is detected by ESC  24  which responds by energizing transistor  146  and thereby energizing pump inhibit relay  46  until ESC  24  again determines that the conditions for emergency pump motor operation are met. Were there no pump inhibit relay  46 , any closure of remote switch  110  would cause emergency pump motor and solenoid  54  to briefly operate, which has the potential of decreasing the life of the solenoid and motor. 
     Operation of emergency pump motor and solenoid  54  can also occur after an unsuccessful engine crank. ESC  24  maintains pump inhibit relay  46  in an energized state until the conditions for emergency pump motor and solenoid  54  operation are met. Following a crank attempt which fails, an operator releases remote switch  110  to discontinue cranking. The operator then depresses remote switch  110  and holds it closed to initiate operation of the emergency pump motor and solenoid  54 . See FIG.  9 . ESC  24  will detect the closed remote switch  110 . Even though the engine is not running, ESC  24  does not initiate a crank operation (by supplying the appropriate signals at output  136  and changing the state of transistor  134 ) since the last command was to crank the engine. ESC  24  is programmed instead to engage emergency: pump motor and solenoid  54  following a failed cranking attempt, even if ESC  24  suffered a reset due to low battery voltage during cranking. Three seconds after remote switch  110  is closed ESC  24  deenergizes transistor RD 13   146 . This in turn deenergizes pump inhibit relay  46 . Closure of remote switch  110  has already supplied a ground connection to the ground side contact of the energization coil of pump relay  36 , resulting in the pump relay becoming energized. Deenergized pump inhibit relay  46  supplies ignition voltage from pump relay  36  to emergency pump motor and solenoid  54  and the emergency pump motor begins to operate until remote switch  110  is released. Opening of remote switch  110  causes pump relay  36  to deenergize, interrupting ignition voltage to pump inhibit relay  46  and cutting off power to emergency pump motor and solenoid  54 . Pump inhibit relay  46  remains energized by a reenergized RD  13  transistor  146  until the conditions for emergency pump motor operation are again met. 
     Emergency pump motor and solenoid  54  operation are also available in case of a complete failure of ESC  24 . If ESC  24  fails, the pump inhibit signal from RD  13  transistor  146  also fails and the pump inhibit relay  46  deenergizes. If battery voltage is still available, ignition voltage is still present on the high side contact and common contact for the energization coil of pump relay  36 . When remote switch  110  is depressed pump relay  36  energizes and couples ignition voltage through to the common contact of now deenergized pump inhibit relay  46 . Pump inhibit relay couples the ignition voltage through to emergency pump motor and solenoid  54  which is energized whenever, and for as long as, remote switch  110  is closed. No three-second delay occurs for pump operation under conditions of failure of ESC  24 . 
     FIGS. 11 and 12 are flow charts for programming of ESC  24  to implement certain features of the present invention for the embodiment not incorporating and the alternative embodiment incorporating an emergency pump motor, respectively. The programs implement logical testing for the conditions under which the vehicle&#39;s engine is stopped or started and the emergency pump motor is run. When the conditions for an engine stop are met ESC  24  provides the required signals for invoking particular operations. For example, for a remote engine stop, a 1 amp FET low side driver associated with ESC output  136  is deactivated and remote stop relay  114  is activated and remains activated until either multiple position ignition switch  102  is moved to OFF or an engine crank sequence has begun. For a vehicle equipped with an emergency pump motor the remote stop relay  114  remains activated until the ignition switch is turned to off, or the remote switch  110  is held closed for a period exceeding a delay period, or an engine crank is requested. Programming helps determine if the conditions for an engine stop are met, which are: (1) the engine is running; (2) the multiple position ignition switch is NOT in the OFF position; (3) remote switch  110  is depressed; (4) the remote switch  110  has just been depressed; (5) the park brake is set; (6) the status of the engine speed message signal is good; and (7) if a PTO interlock variable is set, the PTO switch is on and has good status. Where the vehicle is equipped with an emergency pump motor then the last condition (no. 7) is simply that the status of the engine speed signal is good. When the engine controller determines that the engine has started it discontinues cranking. 
     The engine can be remotely started under the following conditions: (1) The engine is not running; (2) the key is not in the OFF position; (3) the plunger switch is depressed; (4) the plunger switch has just been depressed; (5) the park-brake is set; and (6) if the PTO interlock is set, then the PTO switch is on and has good status. For a vehicle with an emergency pump motor condition  6  is replaced with the condition that: the previous sequence with the engine not running was an emergency pump motor operation sequence or the previous sequence was an engine stop sequence using remote switch  110 . 
     Emergency pump motor inhibit relay  46  is activated when ignition switch  102  is not in the off position and any one of the three following conditions is met: (1) the accessory signal is ON and NEW, or (2) the engine state is ON and NEW, or (3) the remote switch  110  has just been released. Pump inhibit relay  46  is deactivated when the ignition switch  102  is OFF or all of the following conditions are met: (1) ignition switch  102  is not OFF; (2) remote switch  110  is closed; (3) remote switch  110  has been dosed for longer that the programmed delay period after stopping the engine to run the emergency pump motor  59 . Finally, it an emergency pump motor is present it will also run if the multiple position ignition switch  102  is not in the OFF position, the remote switch  110  is depressed, no other functions are currently running (engine stop, cranking, etc.) and the conditions are such that no other function will run. 
     Referring particularly to FIG. 11, execution of the program for a vehicle not having an emergency pump motor begins with determination at step  200  of the position of the ignition switch. If the ignition switch is not in the OFF position the Key_State is true and execution continues to step  202 . If NO the variables Engine_Stop_Relay_Cmd and Engine_Crank_Cmd are reset at step  222  and processing stops. At step  202  ESC  24  determines if remote switch  110  is depressed. If no, the Engine_Crank_Cmd variable is reset at step  224  and processing stops. If a yes resulted at step  202 , execution continues to step  204  where the value of the variable “Tem_Rem_Start_Stop_Plunger” is checked. If the value is “NEW”, i.e. the remote switch is newly depressed a value of 1 is stored on a stack in memory, otherwise a value of 0 is entered. A logical AND operation is then implemented on the stack. Next, at step  206  it is determined in the remote stop start PTO interlock is set. If the PTO interlock is set, step  208  is executed to determine if the PTO engagement switch is on and a logical AND operation is performed with 1 and the stack. Otherwise the stack is “ANDed” with 0. At step  210 , following step  208  or along the NO branch from step  206 , it is determined if the Parking brake is engaged. If yes the stack is ANDed with 1, otherwise with zero. Next, at step  212 , if the ignition signal (Ign) to engine controller is on an “AND” operation is performed on the stack with 1 it the Engine_State has a good status. Otherwise the AND operation on the stack uses a 0. Next, at step  214  the stack is interrogated to see if it has the value 1. If NO the conditions for remote start or stop have not been met and processing is exited. If YES, the conditions for a remote stop or start have been met and step  216  is executed to determine if the engine is running. If YES, the Engine_Stop_Relay_Cmd is set and transistor RD 15   134  is energized. If NO, the engine stop relay command is reset and engine crank command is issued on output  136 . 
     The required logic is more complex if an emergency pump motor is provided. Referring to FIG. 12 a flow chart for a vehicle equipped with an emergency pump motor is illustrated. Again processing begins with a determination of the key state at step  230  (i.e. the key is not in the OFF position). If the key is in the OFF position (the NO branch), step  268  is executed to reset each of four variables: (1) Engine_Crank_Cmd; (2) Engine_Stop_Relay_Cmd; (3) EmergencyPump_inhibit_Relay; and (4) Start_Stop_Timer and the process is terminated. Otherwise processing continues to step  232  which tests to see if one of three conditions is met (1) if the Accessory_Signal is on or new (in this version the invention also works for ACC being on in the ignition switch  102 ); (2) the Engine state is on or new; or (3) the remote switch is newly open. If yes, step  234  is executed to set the emergency pump motor relay and to stop the remote switch closed timer. Following the NO branch from step  232  or after step  234  it is determined if the remote switch is dosed. If NO, the routine is exited via step  270  with reset of the engine crank command and the remote switch closure timer. Otherwise step  238  is executed to determine if the remote switch timer has expired. If yes, the process is exited via step  272  with a reset of the emergency pump motor inhibit relay and turning off the timer. Otherwise, along the NO branch from step  238 , step  240  is executed to put a 1 on the stack if the remote switch is newly closed. Next, at step  242 , if the parameter remote stop/start PTO interlock is set, an AND operation is performed between the stack and 1, but only if the PTO engagement switch is on and has a good status. Otherwise an AND operation is performed between the stack and 0. Next, at step  244 , an AND operation between the stack and 1 is done if the parking brake is set, but otherwise with 0. 
     Next, at step  246  it is determined if the signal Ign is high (as reported by the Engine Controller). If YES, step  248  is executed to determine if the engine status is bad and the remote switch is newly depressed. If YES, step  250  provides that a remote shut down flag be set and remote switch depression timer be started along with a stop timer. Following either the NO branch from step  248  or after step  250 , if engine status is bad an AND operation between the stack and 0 is done, but otherwise the AND operation is done against 1. Next, along the NO branch from step  246  or after step  252 , the value of stack is compared to 1. If it is not 1, processing ceases. Otherwise, along the YES branch it is determined if the engine state is true. If YES, the engine stop relay command and remote shut down flags are set The remote switch closure timer is started and the engine stop timer is started and processing stops. Following the NO branch from step  256 , the remote switch timer is stopped and the engine stop relay command is reset. Next, at step  262  it is determined it the remote shut down flag is set. If YES, the engine crank command is reset and the remote shut down flag is reset. If NO, the remote shut down flag is set, the remote switch timer is started and the remote switch time. Processing then discontinues. 
     The present invention provides a simple, multifunction remote start/stop control system for a utility vehicle that exhibits robustness. A single control may be used to invoke not only starting and stopping, but also to actuate an electric motor-driven pump in case of engine failure. 
     While the invention is shown in only one of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit and scope of the invention.