Method, control unit and control system for operating a vehicle's powertrain

Abstract

Method for operating a powertrain (1) of a vehicle, wherein the powertrain (1) comprises a drive unit (AM), an output (AB) and an automated transmission (GE) which is arranged in the powertrain (1) between the drive unit (AM) and the output (AB), wherein an input shaft (W1) of the transmission (GE) is connected to the drive unit (AM) via a controllable disconnect clutch (TK) and an output shaft (W4) of the transmission (GE) is connected to the output (AB), wherein during a shutdown process of the drive unit (AM) the transmission (GE) is moved into a neutral position, the neutral position of the transmission (GE) is validated by means of a shutdown-side gate movement in a selector gate (WG) of the transmission (GE) and a result of the validation is stored in a control unit (3a) in a non-volatile memory (7) thereof,wherein a subsequent start operation of the drive unit (AM) is possible with the transmission (GE) in neutral position, wherein during the subsequent start operation the result of the plausibility check of the neutral position of the transmission (GE) stored in the non-volatile memory (7) is taken into account such that when an ignition (14) is actuated, the non-volatile memory (7) is read out, wherein if data about a plausible neutral position of the transmission (GE) are read out of the non-volatile memory (7), the transmission (GE) is considered plausible during the subsequent start operation of the drive unit (AM) without an ignition-side gate movement in the selector gate (WG) and the start operation of the drive unit (AM) is permitted, wherein if data about an implausible neutral position of the transmission (GE) are read out of the non-volatile memory (7), or then,If no data is read from the non-volatile memory (7), an ignition-side gate movement is triggered in the selector gate (WG) of the transmission (GE), and depending on this, the starting process of the drive unit (AM) is permitted, whereby if the ignition-side gate movement in the selector gate (WG) of the transmission (GE) is feasible, the starting process of the drive unit (AM) is permitted, and if the ignition-side gate movement in the selector gate (WG) of the transmission (GE) is not feasible, the starting process of the drive unit (AM) is nevertheless permitted, and a warning message perceptible to a driver is generated.

Description

[0001] The invention relates to a method for operating a vehicle's powertrain. Furthermore, the invention relates to a control unit and control system for operating a vehicle's powertrain.

[0002] Vehicles equipped with an automated transmission are parked in neutral. This is because, if a gear (a specific gear ratio) is engaged and the disconnect clutch between the transmission and the drive unit is closed, the drive unit cannot be started. For example, in commercial vehicles, after extended periods of parking, it is not guaranteed that the vehicle's pneumatic system will contain enough air to shift the transmission into neutral or disengage the disconnect clutch upon restart, as compressed air can leak from the vehicle's system. If the transmission is in neutral when the vehicle is parked, the drive unit is disengaged and can be started.

[0003] From DE 10 2016 224 243 A1, a method for operating the powertrain of a motor vehicle with an automated transmission is known. A start-up of the drive unit is possible when the transmission is in neutral. When the drive unit is switched off, the automated transmission is moved to neutral, and the neutral position of the transmission is verified by a movement of the selector lever. The result of this verification is stored in a non-volatile memory of a control unit. During a subsequent start-up of the drive unit, the non-volatile memory is read. If the memory contains data indicating that the neutral position of the transmission is plausible, the transmission is considered verified during the subsequent start-up of the drive unit without requiring another movement of the selector lever.

[0004] In particular, if the result of the transmission neutral position plausibility check cannot be stored in non-volatile memory during the drive unit shutdown process, or if stored information about the plausibility check result cannot be read from non-volatile memory for a subsequent drive unit start-up, this would prevent the drive unit from starting. This would limit vehicle availability. There is a need to increase vehicle availability without compromising safety.

[0005] The invention is based on the objective of creating a method, a control unit and a control system for operating a powertrain, with which the availability of the vehicle can be increased without reducing safety.

[0006] This problem is solved by a method for operating a vehicle's drivetrain according to claim 1. In the method according to the invention, when the drive unit is switched off, the transmission is moved to a neutral position. The neutral position of the transmission is validated by means of a gate movement in a selector gate of the transmission during the switch-off process, and the result of this validation is stored in a control unit in a non-volatile memory. A subsequent start of the drive unit can be performed with the transmission in neutral, whereby the result of the validation of the transmission's neutral position stored in the non-volatile memory is taken into account during the subsequent start. For this purpose, the non-volatile memory is read when the ignition is activated.If data indicating a plausible neutral position of the transmission is read from the non-volatile memory, the transmission is considered plausible during the engine start process, even without ignition-side movement in the selector gate, and the engine start process is permitted. If data indicating an implausible neutral position of the transmission is read from the non-volatile memory, or if no data is read from the non-volatile memory, ignition-side movement in the selector gate of the transmission is triggered, and the engine start process is permitted depending on this.

[0007] The invention proposes that, when reading the non-volatile memory for a start-up process, data indicating an implausible neutral position of the transmission is retrieved, or when no data is retrieved from the non-volatile memory, a start-up of the drive unit should be permitted depending on a renewed movement of the gear selector in the transmission, referred to as the ignition-side gear selector movement. In this case, such an ignition-side gear selector movement is triggered by the control unit, and the start-up of the drive unit is permitted depending on this control-triggered gear selector movement. This increases vehicle availability without compromising safety.

[0008] A neutral position of the transmission refers specifically to a switching state in which the transmission is in neutral. In neutral, the torque flow between an input shaft and an output shaft is interrupted by the corresponding switching position of at least one or all of the necessary shift elements of the transmission. A shift element of the transmission serves specifically to shift the transmission, i.e., to engage and disengage at least one gear (i.e., a specific gear ratio). Depending on the switching position of the shift element(s), either a corresponding gear or neutral is engaged.

[0009] Following a beneficial further development, if the ignition-side gate movement in the transmission's selector gate is feasible, the engine start process is permitted. If the ignition-side gate movement in the transmission's selector gate is not feasible (for example, due to a lack of power), the engine start process is still permitted, and a warning message perceptible to the driver is generated. These details also serve to increase vehicle availability without reducing safety.

[0010] Following an advantageous further development, an authorized start procedure of the drive unit is only released for execution if the position value of at least one switching element of the transmission lies within a defined value range, in particular a switching element of a main gearbox of the transmission. This further development also serves to increase vehicle availability while maintaining a high level of safety. The defined value range corresponds in particular to the neutral position of the transmission. Therefore, if the at least one switching element occupies a position within the defined value range, the transmission is switched to the neutral position.

[0011] Optionally, several or all of the transmission's shift elements are required to engage neutral. Each of these must then assume a specific shift position for the transmission to be in neutral. In this case, the authorized start procedure of the drive unit is only permitted if the respective position value of the transmission's shift elements required for neutral is within the defined value range for neutral.

[0012] To determine the position value, preferably at least one sensor is provided that detects the distance traveled by the switching element or the position of the switching element itself. This sensor can also be referred to as a switching position sensor. The sensor can, in particular, be arranged in the area of ​​a switching rail of the switching element in order to detect the distance traveled or the position of the switching rail and thus of the associated switching element.

[0013] The control unit according to the invention is defined in claim 5 and the control system according to the invention is defined in claim 9.

[0014] Preferred embodiments are described in the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail with reference to the drawing, without being limited thereto. The drawing shows: Fig. 1 a gear diagram of an exemplary group gearbox with a three-stage main gearbox; Fig. 2 an exemplary gear shift diagram of the three-stage main gearbox; Fig. 3 a block diagram of a control system; Fig. 4 a signal flow diagram to illustrate the invention.

[0015] Fig. Figure 1 shows an exemplary automated transmission designed as a group transmission. GE in conjunction with a drive unit AM , wherein an input waveW1 of the gearbox GE via a controllable disconnect coupling TK with the drive unit AM is connected. To an output wave W4 of the gearbox GE is a drive AB connectable, which is in Fig. 1 is not shown. The downforce AB However, is in Fig. 3 shown, where in Fig. 3 the drive unit AM , the gearbox GE , the downforce AB as well as the disconnect coupling TK shown together with control-side assemblies.

[0016] In the illustrated embodiment, the automated transmission, designed as a group transmission, comprises GE a main gearbox HG , one of the main gearbox HG Drive-related upstream switching group or split group VG as well as one to the main gearbox HG downstream area group BG .

[0017] The main gearbox HG In the illustrated embodiment, it is designed as a direct drive gearbox in a reduction gear design and has a main shaft W2 as well as two intermediate shafts W3a and W3b On. Onto the countershaft W3a A controllable transmission brake is in effect GBR a.

[0018] The main gearbox HG of the automated transmission GE In the illustrated embodiment, it is designed as a three-stage main gearbox, providing three transmission stages. G1 , G2 and G3 for one forward movement and one gear ratio R Ready for reverse travel. Loose gears of the transmission stages. G1 , G2 , G3 and R are each on the main wave W2 stored and via associated switching couplings S1 / R , S2 / 3 Switchable. The switching clutches S1 / R , S2 / 3 The switching elements of the main gearbox are formed HGThe associated fixed gears are rotationally fixed to the countershafts. W3a and W3b arranged.

[0019] The translation stage trained as a direct approach G3 of the main gearbox HG is via a direct shift clutch or a shift package SV Switchable. The direct-shift clutch or shift package. SV forms the switching element of the upstream group VG The shift clutches of the transmission stages G3 and G2 as well as the shift clutches of the transmission stages G1 and R are each part of a common switching package S2 / 3 or S1 / R In summary, the main gearbox HG is designed to be switched unsynchronized.

[0020] The pre-group VG of the automated transmission designed as a group transmission GEIn the illustrated embodiment, it is designed as a two-stage transmission and constructed using a reduction gear design. The transmission stages K1 and K2 the pre-group VG form two switchable input constants of the main gearbox HG Due to a smaller translation difference between the two translation stages K1 and K2 is the pre-group VG Designed as a split group. A loose gear of the first gear stage. K1 is rotatable on the input shaft W1 The input shaft is mounted. W1 of the gearbox GE is via the disconnect coupling TK to the drive unit AM coupled. A loose gear of the second gear stage K2 the pre-group VG It is rotatable on the main shaft W2 Bearings. Fixed gears for both gear ratios. K1 you K2 the pre-group VGare each rotationally fixed to the input-side extended countershafts W3a and W3b connected to the main gearbox. The synchronized shift clutches of the pre-selector group. VG are part of the shift package SV summarized.

[0021] The main gearbox HG of the gearbox GE subordinate area group BG of the gearbox GE It is of planetary design and has a two-stage configuration. A sun wheel PS the area group constructed in planetary design BG is rotationally fixed with the main shaft extended on the output side W2 connected to the main gearbox. The planet carrier PT the area group constructed in planetary design BG is rotationally fixed to the output shaft W4 of the gearbox GE coupled. A ring gear PH comes with a shift package SB in connection through which the area group BG alternately through the connection of the ring gear PH with a fixed housing part in slow-speed mode L or by connecting the ring gear PH with the planetary carrier PT into a high-speed setting S It is switchable. The switching package SB forms the switching element of the area group BG The area group BG is designed to be synchronously switchable.

[0022] The drive unit AM , the downforce AB as well as the area between the drive unit AM and the downforce AB manual, automated transmissions GE form the main components of a powertrain 1 of a vehicle, wherein, as already explained, the drive unit AM and the gearbox GE the disconnect coupling TK is switched on.

[0023] For controlling and / or regulating the operation of the drive train1 The vehicle includes a control system 2 , whose basic structure in Fig. 3 is shown. The control system 2 includes several control units, namely a transmission control unit 3a and an engine control unit 3b The transmission control unit 3a It serves to control and / or regulate the operation of the gearbox. GE and preferably the disconnect coupling TK The engine control unit 3b It serves to control and / or regulate the operation of the drive unit. AM .

[0024] The control units 3a and 3b exchange via a data bus system 5 , preferably via a CAM data bus, data from connections. 4 visualize that the control units 3a and 3b with the drivetrain components 1 , namely with the drive unit AM , the disconnect coupling TK , the gearbox GEand the downforce AB exchange data, as well as with other assemblies 12 , 13 and 14 of the drivetrain, namely with a service brake 12 , a driver's switch 13 and an ignition 14 .

[0025] For the transmission control unit 3a are components 6 until 11 shown in the component 6 This is a processor. Regarding the component... 7 to create a memory. Regarding the component 8 A data interface for receiving data. Regarding the component 9 about an evaluation unit. Regarding the component 10 to provide a data interface for sending data. Regarding the components 6 , 7 , 8 , 9 and 10 These are hardware components of the transmission control unit. 3a Furthermore, the transmission control unit includes 3ba software component, i.e., software 11 .

[0026] Fig. 2 illustrates the main gearbox HG the Fig. 1 a so-called gear shift diagram for the transmission stages G1 , G2 , G3 and R on the main wave W2 of the main gearbox HG This is a so-called H-pattern circuit diagram, which uses conventional operating devices and the components in Fig. 1 shown shift clutches S1 / R , S2 / 3 in two shift gates SG1 and SG2 the translation stages G1 , G2 and G3 as well as the translation stage R are switchable. The two shift gates SG1 and SG2 are accessible via a voting lane in the usual manner WG interconnected.

[0027] According to Fig. The translation stage is located at level 2. G1of the first forward gear and the transmission stage R of reverse gear in a first shift gate SG1 The translation stage G2 of the second forward gear and the translation stage G3 The third forward gear is located in a second shift gate. SG2 The shift clutches of the transmission stages G3 and G2 as well as the shift clutches of the transmission stages G1 and R are each associated with the switching packages S2 / 3 or S1 / R summarized.

[0028] Especially for performing a gear change in the main gearbox HG At least one of the clutches will S1 / R , S2 / 3 of the main gearbox HG automated in the sense of the gearshift pattern of the Fig. 2 moves, specifically according to the associated shift gate SG1 or SG2 The selection of the shift gate SG1 , SG2and thus the selection of the shift clutch S1 / R , S2 / 3 This is done by a dialing motion across the dialing lane. WG The one from the respective clutch S1 / R , S2 / 3 distance traveled or the position of the clutch S1 / R , S2 / 3 can be detected by a sensor. This sensor can, for example, be located in the area of ​​a switching rail for the respective switching coupling. S1 / R , S2 / 3 be arranged. The dialing movement via the dialing aisle. WG It can also be detected by a sensor.

[0029] Then, when a vehicle whose powertrain 1 an automated transmission GE exhibits, shut down and thereby the drive unit AM when switched off, the transmission GE automatically shifted to a neutral position. In particular, the clutches are used for this purpose. S1 / R , S2 / 3 of the main gearbox HGeach is transferred to a shift position corresponding to the neutral position of the transmission. GE corresponds.

[0030] The neutral position of the transmission GE This is then done by means of a lane movement on the side of the shutdown process in the selector lane. WG of the gearbox GE plausibility checks, with one result of these plausibility checks being stored in the transmission control unit. 3a in the non-volatile memory 7 is deposited. Such a lane movement is usually only possible if the shift clutches are engaged. S1 / R , S2 / 3 in the respective switch position for the neutral position.

[0031] The shutdown process-side lane movement should be a lane movement in the dial lane. WG of the gearbox GE to be understood, which are responsible for the shutdown process of the drive unit AM is performed when the vehicle is parked.

[0032] A subsequent start-up process for the drive unit AM is when the transmission is in neutral GE feasible. For a subsequent startup process to be executed, this is stored in non-volatile memory. 7 stored result of the shutdown process of the drive unit AM Plausibility check of the neutral position of the gearbox performed GE This is taken into account. This is done by ensuring that when the ignition is activated... 14 the vehicle's non-volatile memory 7 is read out. This happens when data about a plausible neutral position of the transmission is obtained. GE from non-volatile memory 7 The data will be read out during the start-up process of the drive unit. AM the gearbox GE considered plausible and the starting process of the drive unit AMApproved, specifically without any ignition-side gas movement. This occurs when reading the non-volatile memory. 7 Data regarding an implausible neutral position of the transmission GE from non-volatile memory 7 can be read out, or when no data is available from the non-volatile memory. 7 If the data can be read out, then an ignition-side lane movement in the selector lane will occur. WG of the gearbox GE triggered and, depending on this, the starting process of the drivetrain AM Approved. An ignition-side gas movement is understood to mean a gas movement resulting from the activation of the ignition. 14 is executed.

[0033] The invention makes it possible, in particular, to avoid problems such as a malfunction of the transmission control unit. 3a during the shutdown process of the drive unit AMThe result of the plausibility check is not stored in non-volatile memory. 7 The availability of the vehicle can be increased if the non-volatile memory cannot be read during a subsequent start process, namely by triggering the ignition-side gate movement in the selector gate. WG of the gearbox GE , and by allowing the start-up process of the drive unit AM depending on this triggered, ignition-side gas movement.

[0034] Further details of the invention are described below with reference to the block diagram of the Fig. 4 described.

[0035] The block 15 the Fig. Figure 4 visualizes the execution of a shutdown-side lane movement in the selector lane. WG of the gearbox GE during a shutdown process of the drive unit AM During the shutdown process of the drive unit AMwill the gearbox GE moved to neutral position and the neutral position of the transmission GE is achieved by means of the block's lane movement on the shutdown process side 15 plausibility check. The result of the plausibility check, i.e., whether the neutral position of the transmission is plausible or implausible, is determined. GE is present, will be in block 15 in non-volatile memory 7 of the transmission control unit 3a saved.

[0036] The block 16 visualizes a subsequent start-up process for the drive unit AM , which is activated by turning on the ignition 14 is triggered, whereby the non-volatile memory is used. 7 of the transmission control unit 3a is read out in block 16 This process involves accessing the non-volatile memory 7 of the transmission control unit 3b a plausible neutral position of the gearbox GEread out. In this case, it is then read into a block. 16 the gearbox during the starting process of the drive unit AM without an ignition-side lane movement in the selector lane WG considered plausible and the starting process of the drive unit AM in block 16 approved.

[0037] block 17 the Fig. 4 visualizes a state in which, when reading the non-volatile memory 7 of the transmission control unit 3b , which results from the activation of the ignition 14 is read out, an implausible neutral position of the transmission is read out, or a state in which, for example, no data is read from the non-volatile memory due to a fault. 7 can be read out, particularly because the result of the plausibility check is not stored in non-volatile memory during the shutdown process of the drive unit. 7could not be stored, or because the non-volatile memory was affected by a communication failure. 7 cannot be read.

[0038] It will then be in block form. 17 an ignition-side lane movement in the selector lane WG of the gearbox GE The process is triggered and evaluated. Depending on this, the starting procedure of the drive unit is then initiated. AM approved.

[0039] In block 17 This results in an ignition-side lane movement in the selector lane. WG of the gearbox GE Triggered. The lane movement is monitored, in particular, using a sensor. This occurs when the ignition-side lane movement in the selector lane is detected. WG of the gearbox is feasible and therefore the gearbox GE In neutral, it is in block 18 the starting process of the drive unit AMpermitted. However, if it is determined that the triggered ignition-side gas movement in the selector lane WG of the gearbox GE If the operation cannot be carried out or is not feasible, the block will be used. 19 the starting process of the drive unit AM nevertheless permitted and generates a perceptible warning message for the driver, for example a display message or a warning tone, which alerts the driver to the starting process of the drive unit. AM warns and, for example, prompts the user to apply the brakes, so that as a result of the starting process of the drive unit AM This prevents unwanted starting.

[0040] In the blocks 16 , 18 and 19 Each start-up process of the drive unit will be performed. AM Permitted by the control system. An authorized start procedure is defined in the blocks. 16 , 18 and 19However, execution is only actually authorized if a sensor-detected position value of the switching clutches is received. S1 / R , S2 / 3 of the main gearbox HG within a defined range of values, which corresponds to the neutral position of the transmission GE corresponds.

[0041] The invention further relates to the transmission control unit 3a trained control unit for operating the transmission GE , where the transmission control unit 3b The control unit executes the procedure described above, i.e., it is configured to execute the procedure described above. 3b transferred during a shutdown process of the drive unit AM the drivetrain, the transmission GE into neutral position and confirms the neutral position of the transmission. GE by means of the switching-off process-side lane movement in the selector lane WG , where the control unit 3bthe result of this plausibility check in the non-volatile memory 7 lays down.

[0042] Is activated by turning on the ignition? 14 a subsequent start-up process of the drive unit AM requested, the control unit takes this into account 3b during the subsequent startup process, the non-volatile memory 7 stored result, for which the control unit 3b when the ignition is activated 14 the non-volatile memory 7 reads out.

[0043] Then, when the control unit 3b determines that data regarding a plausible neutral position of the gearbox GE from non-volatile memory 7 The control unit considers the data that can be read out. 3b the gearbox GE The subsequent starting process without an ignition-side gas movement is considered plausible and allows the starting process of the drive unit to proceed. AM to.

[0044] Then, when the control unit 3b determines that data can be read via an implausible neutral position or that no data can be retrieved from the non-volatile memory 7 The control unit triggers the readable data. 3b the ignition-side lane movement in the selector lane WG of the transmission and, depending on this, allows the starting process of the drive unit to begin. AM in the manner described above.

[0045] The invention further relates to the control system 2 , which is the transmission control unit 3a as well as the engine control unit 3b includes the transmission control unit. 3a executes the procedure described above and transmits an engine start enable signal to the engine control unit, depending on the procedure performed. 3b . Reference symbol list 1 Powertrain 2. Tax system 3a Transmission control unit 3b Engine control unit 4 connection 5 Data bus system 6 processor 7 storage 8 Receive data interface 9 evaluation unit 10. Transmitting data interface 11 Software 12 Service brake 13 Driver's switch 14 Ignition 15 blocks Block 16 Block 17 Block 18 Block 19 AM drive unit TK disconnect coupling GE gearbox AB drive VG pre-group SV switching package, switching element K1 first translation stage K2 second translation stage HG main gearbox G1 first translation stage G2 second translation stage G3 third translation stage R Reverse gear ratio S1 / R switching package, switching element S2 / 3 switching package, switching element BG Area Group SB switching package, switching element L Slow speed setting S High speed setting PH ring gear PS Sun wheel PT Planetary Carrier W1 Input shaft W2 Main shaft W3a Countershaft W3b countershaft W4 output shaft SG1 shift gate SG2 shift gate WG Wählgasse GBR gearbox brake QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102016224243 A1

[0003]

Claims

[1] Method for operating a powertrain (1) of a vehicle, wherein the powertrain (1) comprises a drive unit (AM), an output (AB) and an automated transmission (GE) which is arranged in the powertrain (1) between the drive unit (AM) and the output (AB), wherein an input shaft (W1) of the gearbox (GE) is connected to the drive unit (AM) via a controllable disconnect clutch (TK) and an output shaft (W4) of the gearbox (GE) is connected to the output (AB), wherein, during a shutdown process of the drive unit (AM), the transmission (GE) is moved into a neutral position, the neutral position of the transmission (GE) is validated by means of a shutdown-side gate movement in a selector gate (WG) of the transmission (GE), and a result of the validation is stored in a control unit (3a) in a non-volatile memory (7) thereof, where a subsequent start-up of the drive unit (AM) is possible with the transmission (GE) in neutral position, wherein, during the subsequent start-up process, the result of the plausibility check of the neutral position of the transmission (GE) stored in the non-volatile memory (7) is taken into account in such a way that when an ignition (14) is activated, the non-volatile memory (7) is read out, where, if data about a plausible neutral position of the transmission (GE) is read from the non-volatile memory (7), the transmission (GE) is considered plausible during the subsequent start process of the drive unit (AM) without an ignition-side gate movement in the selector gate (WG) and the start process of the drive unit (AM) is permitted, wherein, if data about an implausible neutral position of the transmission (GE) is read from the non-volatile memory (7), or if no data is read from the non-volatile memory (7), an ignition-side gate movement in the selector gate (WG) of the transmission (GE) is triggered and, depending on this, the starting process of the drive unit (AM) is permitted. [2] Method according to claim 1, characterized by , that when the ignition-side gas movement in the selector lane (WG) of the transmission (GE) is feasible, the starting process of the drive unit (AM) is permitted. [3] Method according to claim 1 or 2, characterized by , that if the ignition-side gate movement in the selector gate (WG) of the transmission (GE) is not feasible, the starting process of the drive unit (AM) is nevertheless permitted and a warning message perceptible to a driver is generated. [4] Method according to any one of claims 1 to 3, characterized by , that an authorized start operation of the drive unit (AM) is only released for execution if a position value of at least one switching element (S1 / R, S2 / 3) of the transmission (GE) lies within a defined value range, wherein in particular the defined value range corresponds to a neutral position of the transmission (GE). [5] Control unit (3a) for operating a transmission of a vehicle, wherein, during a shutdown process of a drive unit (AM), the control unit moves the transmission (GE) into a neutral position, the neutral position of the transmission (GE) is validated by means of a shutdown-side gate movement in a selector gate (WG) of the transmission (GE) and a result of the validation is stored in a non-volatile memory (7), wherein the control unit takes into account the result of the plausibility check stored in the non-volatile memory (7) during the subsequent start-up process such that the control unit reads the non-volatile memory (7) when the ignition (14) is activated, where the control unit, if it determines that data about a plausible neutral position can be read, considers the transmission (GE) as plausible during the start-up process of the drive unit (AM) without an ignition-side gate movement in the selector gate (WG) and allows the start-up process of the drive unit (AM), whereupon the control unit, when it determines that data about an implausible neutral position or no data can be read, triggers an ignition-side gate movement in the selector gate (WG) of the transmission (GE) and, depending on this, allows the starting process of the drive unit (AM). [6] Control unit according to claim 5, characterized by, that if the ignition-side gas movement in the selector lane (WG) of the transmission (GE) is feasible, the starting process of the drive unit (AM) is permitted. [7] Control unit according to claim 5 or 6, characterized by , that if the ignition-side gate movement in the selector gate (WG) of the transmission (GE) is not feasible, the starting process of the drive unit (AM) is still permitted and generates a warning message perceptible to a driver. [8] Control unit according to one of claims 5 to 7, characterized by , that the same only releases an authorized start operation of the drive unit (AM) if a position value of at least one switching element (S1 / R, S2 / 3) of the transmission (GE) lies within a defined value range, wherein in particular the defined value range corresponds to a neutral position of the transmission (GE). [9] Vehicle control system, with a control unit (3a) of a transmission (GE) according to one of claims 5 to 8, with a control unit (3b) of a drive unit (AM), wherein the control unit (3a) of the transmission (GE) generates an engine start enable signal and transmits it to the control unit (3b) of the drive unit (AM).

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