EP2875234A1

EP2875234A1 - Diagnostics for a start system

Info

Publication number: EP2875234A1
Application number: EP13806278.1A
Authority: EP
Inventors: Holger Dreher; Gunnar Ledfelt
Original assignee: Scania CV AB
Current assignee: Scania CV AB
Priority date: 2012-06-19
Filing date: 2013-06-12
Publication date: 2015-05-27
Also published as: CN104471237A; WO2013191617A1; RU2015101278A; EP2875234A4; SE1250655A1; SE536553C2; BR112014031507A2; CN104471237B; RU2605079C2

Abstract

A combustion engine (120) in a vehicle is started by means of a start system including an electric starter motor (110). The function of the start system is evaluated by means of a test system comprising measuring elements, a starter motor analyzer (160) and a control unit (170). The measuring elements measure a supply voltage to the electric starter motor (110) and an rpm of the combustion engine ( 120) when the starter motor (110) is activated. The starter motor analyzer (160) defines, based on the supply voltage and the rpm, a preliminary status (S) of the start system. Based on the preliminary status (S), the control unit (170) evaluates whether information in addition to the supply voltage and the rpm is needed. If such is the case, an interactive communication process is executed wherein an operator (OP) is called upon to input information (OPInp) to the control unit (170) in at least one process step. An expanded status message (TR) that defines a functional status for the start system is generated by the control unit (170) on the basis of the interactive communication process.

Description

Diagnostics for a start system

TECHNICAL BACKGROUND OF THE INVENTION AND PRIOR ART

The present invention refers in general to diagnostics for a start system in a motor vehicle. The invention concerns in particular a test system according to the preamble to claim 1 and a method accordi ng to the preamble to claim 9. The invention also concerns a computer program according to claim 1 7 and a computer-readable medium according to claim 1 8. Essentially all current motor vehicles are equipped with combustion engines that depend upon an electric starter motor to be able to start. The function of the starter motor is thus vital to the operation of the vehicle. Various known solutions exist for verifying this function . For practical reasons, it is understandably preferable that the starter motor not need to be removed from the vehicle in order to test the starter motor. It is further desirable that it be possi ble to eval uate the function of the start system without the vehicle needing to visit a workshop.

US 2012/001 7618 describes a system for predicting whether any faults in a starter motor are imminent. The system monitors the rpm and battery charge of the starter motor, as well as the temperature of the ambient air. The measured values are compared with corresponding predicted values, and an alarm is generated if the rpm is lower than the predicted value. US 2009/021 7897 describes a diagnostics device for a combustion engine with an associated electrical system includi ng a battery. Here again the diagnostics device monitors electrical system parameters, such as the starti ng current and the power supply to the starter motor. US 2012/01 75656 presents a method for monitoring a starter motor system comprising a charging system, a battery, a starter motor and a flywheel . For example, here a charge voltage is compared to predetermined battery charge val ues, and a signal is generated for an operator (such as by lighting a warning lamp) if at least one charge voltage is outside a predetermined range. The operator of the system can also be called upon to perform one or a pl urality of actions in response to the generated signal .

PROBLEMS ASSOCIATED W ITH THE PRIOR ART

Various solutions thus exist for evaluating the function of a start system i n a motor vehicle. However, there is no example of a solution that, on the one hand , enables simple diagnostics during normal operation of a vehicle and , on the other hand , ensures that all appropriate parameters are taken into account in the diagnostics.

SUMMARY OF THE I NVENTION

The object of the present invention is consequently to provide a solution to this problem that enables simple, safe and reliable diagnostics of a motor vehicle start system.

Accordi ng to one aspect of the i nvention , this object is achieved by means of the test system described above, wherein the test system comprises a control unit configured so as to activate the start system only in response to a start request from an operator. It is thereby ensured that a potentially dangerous action , such as starting the vehicle motor, cannot occur i n any way other than on the initiative of the operator. The control unit is also configured so as to perform, based on the preliminary status, the following steps: determine whether i nformation in addition to the supply voltage and rpm is needed for the relevant diagnostics and , if such is the case, execute an interactive communications process. This process consists i n that an operator is called upon to input information to the control unit in at least one process stage. Based on the interactive communication process, the control unit is configured so as to generate an expanded status message, which describes a functional status for the start system. This system is advantageous, as the tests can thus be highly flexible and be based on data pertaining to the vehicle that are highly complicated to obtai n automatically, such as taking i nto account click sounds from the electric starter motor. The interactive communication process is generally advantageous in that it enables an efficient shari ng of actions between operator and machine, such as with regard to measurements and calculations. This in turn ensures both the robustness and accuracy of the system.

Accordi ng to one embodiment of this aspect of the invention , the test system comprises at least one user interface, which is configured so as to present the operator with information generated by the control unit and to receive input signals from the operator. An efficient exchange of i nformation can be effectuated thereby. Accordi ng to another embodiment of this aspect of the invention , the control unit is configured so as to receive at least one sensor signal in addition to basic technical data i n the form of the supply voltage to the electric starter motor and the rpm of the combustion engine. The control unit is configured so as to generate the expanded status message based further on said at least one sensor signal . The tests can thus, for example, be based further on one or a plurality of voltage measurements in critical parts of the start system.

Accordi ng to yet another embodiment of this aspect of the invention , the control unit is configured so as to determine, by means of an i nteractive communication process with an operator, whether the basic conditions for allowing activation of the starter motor are present. The control unit is configured so as to enable activation of the starter motor only if said basic conditions are present. The basic conditions can comprise, for example, fulfillment of a start condition pertaining to an alcohol lock in the vehicle and/or that the combustion engi ne not be runni ng . I mportant safety risks can thereby be avoided . Accordi ng to another embodiment of this aspect of the invention , there is at least one user interface configured so as to receive input signals from the operator pertaining to at least either of acoustical or optical signals generated by the vehicle in connection with activation of the starter motor, such as any suspicious sounds from the motor. This type of data is normally very difficult to obtai n from the vehicle automatically.

Accordi ng to yet another embodiment of this aspect of the invention , the test system comprises one or a plurality of temperature measuring elements configured so as to measure at least one temperature related to the vehicle. The starter motor analyzer is here configured so as to define the preliminary status on the further basis of said at least one measured temperature. For example, the ambient temperature and a characteristic temperature of the combustion engi ne are namely two important parameters for assessing the function of the electric starter motor.

Accordi ng to embodiments of this aspect of the invention , the object is achieved by means of the method described above, wherei n the start system is activated only in response to a start request from an operator. Based on the preliminary status, the following steps are also performed : a determination as to whether information in addition to said basic technical data is needed and , if such is the case, the execution of an i nteractive communication process in which the operator is called upon to input information to the control unit in at least one process step and , based on the interactive communication process, the generation of an expanded status message that defines a functional status of the start system. The advantages of this method and of the preferred embodiments thereof, are presented in the discussion above with reference to the proposed system.

Accordi ng to an additional aspect of the invention , the object is achieved by means of a computer program that is directly downloadable to the internal memory of a computer and comprises software for controlling the steps according to the method proposed above when said program is run on a computer.

Accordi ng to yet another aspect of the i nvention , the object is achieved by means of a computer-readable medium with a program stored thereon , where the program is adapted so as to enable a computer to control the steps according to the method proposed above.

BRI EF DESCRI PTION OF TH E DRAWI NGS

The present invention will now be explained in greater detail with the help of embodiments, which are described as examples, and with reference to the accompanying drawings.

Figure 1 shows a schematic depiction of a proposed system,

Figure 2 shows an overview of how an electric starter motor according to one embodiment of the invention can be arranged so as to start a combustion engine in a motor vehicle,

Figures 3a-b show graphs that illustrate how a preliminary status of a start system can be defined according to embodiments of the invention , and

Figure 4 shows a flow diagram that illustrates the general method according to the invention . DESCRI PTION OF EMBODI M ENTS OF THE I NVENTION

We refer initially to Figure 1 , which schematically depicts a proposed test system for determining the function of a start system in a motor vehicle. The start system is assumed to be arranged so as to start a combustion engine 1 20 in the vehicle by means of an electric starter motor 1 10.

The test system comprises: measuring elements, a starter motor analyzer 160 and a control unit 1 70. Figure 2 shows, in somewhat greater detail , how the electric starter motor 1 1 0 accordi ng to one embodiment of the invention is coupled in to the combustion engine 1 20. Figure 2 also shows the aforementioned measuring elements 130 and 140, which are configured so as to measure basic technical data, incl uding an supply voltage to the electric starter motor 1 10 and an rpm RPM of the combustion engi ne 1 20 when the starter motor 1 1 0 is activated .

The starter motor analyzer 1 60 is configured so as to defi ne a preliminary status S for the start system, based on said basic technical data U . The control unit 1 70 is configured so as to activate the start system only in response to a start request from an operator OP. This is important, as it is ensures that neither the electric starter motor 1 10 nor the combustion engine 120 can be started in any way other than on the initiative of the operator OP, for example by turni ng a start key. It is thus possible to avoid situations that are dangerous for the service personnel , and that arise as a result of the vehicle starting at a time when said personnel do not expect it.

The control unit 1 70 is also configured so as to determine, based on the preliminary status S, whether information is needed in addition to said basic technical data U and RPM i n order to be able to generate an expanded status message describing the functional status of the start system. If such additional information is needed , the control unit 1 70 is configured so as to execute an interactive communication process. This process in turn comprises the operator OP bei ng called upon to input information OPI np to the control unit 1 70 in at least one process step, preferably via a user interface 1 80. The control unit 1 70 is configured so as to generate, based on the i nteractive communication process, an expanded status message TR that describes a functional status of the start system. The user interface 180 is advantageously configured so as to present information DReq and TR generated by the control unit 1 70 to the operator OP by means of a screen and/or acoustical messages. The user interface 180 further suitably comprises at least one element configured so as to receive input signals OPI np from the operator OP, typically in the form of answers to questions Dreq posed by the control unit 1 70 to the operator OP via a user interface 180. The user interface can thus incl ude a keyboard and/or elements for entering voice commands. The user i nterface 180 can thus, for example, be used to receive input signals OPI np from the operator OP concerning acoustical and/or optical signals generated by the vehicle in conjunction with activation of the starter motor 1 10.

Accordi ng to one embodiment of the invention , the control unit 1 70 is configured so as to receive at least one sensor signal [s,] in addition to basic technical data in the form of a supply voltage U to the electric starter motor and rpm RPM of the combustion engine. The sensor signals [s,] can , for example, represent voltage levels at critical points in the start system. The control unit 1 70 is configured so as to generate the expanded status message TR on the further basis of said at least one sensor signal [s,]. If said basic technical data U and RPM provide an insufficient or i nadequate basis, for example, due to an anomaly, the sensor signals [s,] can [constitute] supplementary data for diagnostics of the start system. Because a characteristic temperature of the combustion engine 120 affects the conditions and assumptions of the starter motor 100 in terms of starting the combustion engine 120, the test system according to one embodiment of the invention comprises one or a plurality of temperature measuring elements configured so as to measure at least one temperature related to the vehicle. The starter motor analyzer 160 is here configured so as to define the preliminary status S on the further basis of said at least one measured temperature. The control unit 1 70 is advantageously also configured so as to determi ne, by means of an i nteractive communication process with an operator OP, whether the basic conditions to enable activation of the starter motor 1 10 are present. The control unit 1 70 is configured so as to enable activation of the starter motor 1 1 0 only if such basic conditions are present. Examples of basic conditions of this type are the fulfillment of a start condition pertaini ng to an alcohol lock in the vehicle and that the combustion engi ne 120 not already be runni ng . Safety risks to both people and materiel can be avoided by determining whether these basic conditions are fulfilled .

We return now to Figure 2, which shows an overview of a system according to the invention for diagnostics for a electric starter motor 1 10. The electric starter motor 1 10 is assumed to be included in a vehicle equipped with a combustion engine 120, where the electric starter motor 1 10 is configured so as to start the combustion engine 120. The electric starter motor 1 10 is in turn advantageously powered by a battery 135.

The proposed system comprises measuring elements 130 and 140 and a starter motor analyzer 1 60. Temperature measuring elements (not shown) are also advantageously included .

The measuring elements 130 and 140 are configured so as to measure technical parameters related to the vehicle. The technical parameters represent a supply voltage U to the starter motor 1 10 and an rpm RPM of the combustion engi ne 120. I n the following description we will discuss the rpm RPM of the combustion engine 120 throughout. Because the starter motor 1 10 and the combustion engine 1 20 are coupled together (for example by means of a so-called Bendix cl utch), there is a correlation between the rpm of the combustion engi ne 120 and the rpm of the starter motor 1 10, with the result that a measured rpm of the starter motor 1 10 can be used just as well as the proposed rpm RPM of the combustion engine 120.

Said temperature measuring elements are configured so as to measure at least one temperature T related to the vehicle. Said at least one temperature T can , for example, pertain to an ambient temperature at the vehicle, an oil temperature in the engine, a cooling fluid temperature, an engine block temperature and/or a battery temperature. It is advantageous to register more than one temperature, as this enables a determi nation as to whether the vehicle is bei ng cold-started (all temperatures essentially equal), hot-started (the oil temperature in the engine and a cooling fl uid temperature significantly exceed the ambient temperature) or started i n a semi-hot state (the cooling fluid temperature significantly exceeds the ambient temperature, but the oil temperature in the engine is relatively low).

The starter motor analyzer 1 60 is configured so as to define, based on the measured technical parameters U and RPM and the temperature T, a preliminary status S of the starter motor 1 10, which preliminary status S is a quality metric for the performance of the starter motor 1 10.

For greater reliability/robustness, the measurement elements 130 and 140 accordi ng to one embodiment of the invention are configured so as to measure the technical parameters during a measurement i nterval , such as 1 second , duri ng which measurement interval , for example, 1 0 individual measurements are registered . Alternatively, the measurement interval can be adaptively linked to one or a pl urality of compression cycles of the combustion engine 120, so that the measurement interval represents a whole number of compression cycles. A typical compression cycle is roughly 15 ms long . As an alternative to a pure averagi ng of the rpm RPM , the starter motor analyzer can in such cases be configured so as to register the lowest rpm during a compression cycle. Start performance has in fact shown itself to be dependent upon the speed at which it is lowest. Furthermore, the starter motor analyzer 160 can be configured so as to generate averages between a respective lowest measured supply voltage U to the starter motor 1 10 in each of a number of compression cycles.

The starter motor analyzer 1 60 can thus be configured so as to generate averages of the measured technical parameters over the measurement interval and define the preliminary status S on the basis of an average of the supply voltage U_avg to the starter motor 1 10 during the measurement interval and an average of the rpm RPM_avg of the combustion engine 1 20 duri ng the measurement interval .

In a corresponding manner, the temperature measuring element is suitably configured so as to measure at least one temperature T during a measurement interval . If such is the case, the starter motor analyzer 160 is naturally configured so as to generate the average for said at least one measured temperature T over the measurement i nterval , and to utilize at least one of said at least one averaged temperatures in defining the preliminary status S .

It may further be advantageous to adapt the diagnostic method performed by the starter motor analyzer 1 60 in dependence upon seasonal variations. For example, a temperature adaptation can be performed i n two steps (summer/wi nter), in multiple steps (such as below -25°C, between -25°C and -20°C, between -20°C and - 10°C, between -10°C and ±0°C, between ±0°C and 1 0°C, and above 1 0°C), or continuously on the basis of a defined relationship: RPM_exp = U ^χ P 1 /(T + P2), where RPMexp designates the expected rpm, U designates the measured supply voltage to the starter motor 1 10, T designates a measured temperature and P 1 and P2 are adaptation parameters.

Figure 3a shows a first graph that illustrates how the preliminary status S is assigned according to one embodiment of the invention . The graph shows an average supply voltage U_avg to the starter motor 1 10 on the horizontal axis and an average rpm RPM_avg of the combustion engine 1 20 on the vertical axis.

According to this embodiment of the invention , the starter motor analyzer 160 is configured so as, for example, to categorize the preliminary status S as OK if the function of the starter motor 1 10 is considered to be acceptable, and to categorize the preliminary status S as NOT if the starter motor 1 10 is not considered to be functioning adequately. The preliminary status S is categorized as OK if the measured supply voltage U_avg exceeds a voltage threshold U_th and the measured rpm simultaneously exceeds an rpm threshold RPM_th. It is advantageous to calculate the preliminary status S continuously by comparing a measured rpm RPM to an expected rpm, and to apply at least one threshold level (for example a first level representing acceptable starter motor function OK and a second level correspondi ng to unacceptable starter motor function NOT), for example according to the relationship below:

_{S = 8Q} RPM ₊ N1(T)

U / N2(T) where

RPM designates a measured rpm during a start attempt, T designates a measured temperature (such as a characteristic engine temperature),

U designates a measured supply voltage during the start attempt,

N1(T) designates an rpm offset at the temperature T, and N2(T) designates an rpm parameter at the temperature T.

In the above equation, the preliminary status S = 80 if the function of the starter motor is good. S > 70 can thus correspond to an acceptable starter motor function OK. If, on the other hand, S < 70, the starter motor function is considered to be unacceptable NOT, as a result of which replacing the starter motor should be recommended. It is further advantageous if the starter motor analyzer 160 applies an adaptive secondary condition, which is dependent upon said at least one measured temperature T. This can entail that, at a first temperature T1, the rpm must exceed the rpm threshold RPM_th in relation to the extent to which the supply voltage U_avg exceeds a first control voltage U_bri, where U_bri ≥ Uth- The adaptive secondary condition is advantageously inversely proportional to said at least one measured temperature T.

To illustrate this, we refer to Figure 3b, where a second graph shows how the starter motor analyzer 160 assigns the preliminary status S. In similarity to Figure 3a, the graph here shows an average supply voltage U_avg to the starter motor 110 on the horizontal axis and an average rpm RPM_avg of the combustion engine 120 on the vertical axis. In Figure 3b, a measured temperature T is assumed to have a value T2 > T1. The fact that the adaptive secondary condition is inversely proportional to the measured temperature T means that, at a higher temperature T, a higher rpm RPM_avg for a given supply voltage U_avg is preferred in order for the function of the starter motor 110 to be considered acceptable (and for the preliminary status S to be assigned the first value OK). The temperature-dependent secondary condition according to the graph in Figure 3b consequently has a steeper slope than in Figure 3a.

To make the rpm requirement more rigorous at an i ncreased temperature T, a second control voltage \J_br2 can, at a higher temperature T2 > T1 , also be given a lower value, i .e. U_{b r}2 < U bM , where \J_br2≥ U_th .

The starter motor analyzer 1 60 is thus advantageously configured so as to apply the adaptive secondary condition on the basis of the measured temperature T so that, at a proportionally high measured temperature T2, a relatively low measured supply voltage U_avg must be matched by a measured rpm that exceeds the rpm threshold RPM_th i n order for the adaptive secondary condition to be considered to be met, and for the preliminary status S to be assigned the first value OK. On the other hand, at a proportionally low measured temperature T1 , the starter motor analyzer 160 is advantageously configured so as to assign the preliminary status S so that a relatively high measured supply voltage U_avg can be matched by a measured rpm that is just above the rpm threshold RPM_th, whereupon the adaptive secondary condition is considered to be met, and the preliminary status S is assigned the first val ue OK.

If the measured supply voltage U_avg is below the voltage threshold U_th , it is, as noted above, impossible to determine the starter motor function . According to one embodiment of the invention , the starter motor analyzer 160 is in such a case configured so as to assign the preliminary status S a third value UNDEF , which indicates that the starter motor function cannot be defi ned . The starter motor analyzer 1 60 is suitably controlled so as to function i n accordance with the foregoing by means of a computer program stored in a memory unit 165, which is contai ned in the starter motor analyzer 160 or communicatively connected therewith .

To summarize, the general method accordi ng to the invention will now be described together with a preferred embodiment thereof with reference to the flow diagram in Figure 4.

In a first step 405, a determination is made as to whether a basic condition for activating the starter motor and thereby being able to test it is present. Examples of such basic conditions can be that a start condition pertaining to an alcohol lock in the vehicle must be met, and that the combustion engi ne cannot be runni ng . If applicable basic conditions are met, there follows a step 410, otherwise the process proceeds directly to a step 455. In this step a status message is generated that indicates that least one condition for bei ng able test the start system is not being met. An operator of the vehicle will also suitably be informed as to relevant actions for meeting the necessary conditions.

Step 410 executes an i nteractive communication process wherei n the operator is called upon to input i nformation in at least one process step. This can comprise anythi ng from a very simple confirmation that no transmission gear has been selected to inputting a long sequence of answers, wherein a given question is conditioned upon the answer to a preceding question concerni ng for example, setti ngs and configurations of the vehicle. A step 415 subsequent thereto (which can advantageously be iteratively inserted between each individual question in step 410) determines whether the necessary information has been obtained from the operator. If such is the case, there follows a step 420, otherwise the process loops back to step 410.

Step 420 determines whether the electric starter motor has been activated in response to an operator request. If such is the case, there follow steps 425 and 430 and , if not, the process loops back and stops at step 420.

In step 425, an rpm of the combustion engine is measured , and in step 430 (which is preferably performed in parallel with step 425) a supply voltage to the electric starter motor is measured . A preliminary status of the start system is defi ned in a step 435 on the basis of these basic technical data. A step 440 then determi nes whether additional information is needed to define the functional status of the start system. If it is determined i n step 440 that no additional information is required , but rather that said basic technical data have provided an adequate basis, the process then conti nues to step 455. I n step 455, a status message is generated in this case regarding the functional status of the start system, based exclusively on the aforementioned supply voltage and rpm. If, for example, either of the measurement registrations in step 425 or 430 is unsuccessful (or results in val ues that deviate strongly from those constituting the normal values for a functional start system), the preliminary status defined in step 435 will provide incomplete and/or misleading information about the start system. Step 440 will consequently demand additional information , which in turn results in the process instead continui ng to a step 445. Analogously to step 410 above, an interactive communication process is executed in step 445 wherei n the operator is called upon to input i nformation in at least one process step. Here again the interactive process can comprise anythi ng from inputting a simple confirmation to runni ng through long question-answer sequences. For example, the operator can be called upon to listen for various types of sounds from the start system in response to various actions, and to input information concerning them.

A su bsequent step 450 (which can advantageously be iteratively inserted between each individual question in step 445) determi nes whether information needed from the operator has been obtai ned . If such is the case, step 455 follows, otherwise the process loops back to step 445. I n this case, a status message concerning the functional status of the start system is generated i n step 455 based on both said basic technical data and the i nformation obtai ned via step 445. The process is then concluded .

The method steps described with reference to Figure 4 can be controlled by means of a programmed computer device. Furthermore, although the embodiments of the invention described above with reference to the figures comprise a computer and processes performed in a computer, the invention extends to a computer program , particularly a computer program on or in a carrier adapted so as to implement the invention practically. The program can be in the form of source code, object code, a code that constitutes somethi ng intermediate between source and object code, such as code in partly compiled form, or in any other form whatsoever that is suitable for use in implementi ng the process accordi ng to the invention . The carrier can be any arbitrary entity or device that is capable of serving as a medi um for the program. For example, the carrier can comprise a storage medium such as a flash memory, a ROM (Read Only Memory), for example a CD (Compact Disc) or a semiconductor-ROM , EPROM (Electrically Programmable ROM), EEPROM (Erasable EPROM), or a magnetic recording medium such as a floppy disk or hard drive. The carrier can also be a transmitted carrier such as an electrical or optical signal , which can be conducted through an electrical or optical cable or by radio in some other way. When the program is realized as a signal that can be conducted directly by a cable or other device or element, the carrier can consist of such a cable, device or element. Alternatively, the carrier can be an integrated circuit in which the program is embedded , wherein the integrated circuit is adapted so as to perform, or to be used in connection with the performance of, the relevant processes.

The invention is not limited to the embodiments described with reference to the figures, but rather can be varied freely withi n the scope of the following claims.

Claims

1 . A test system for determining the function of a start system in a vehicle, which start system is arranged so as to start a combustion engine (120) in the vehicle by means of an electric starter motor (1 10), which test system comprises:

measuri ng elements ( 130, 140) configured so as to measure basic technical data, including a supply voltage (U) to the electric starter motor ( 1 10) and an rpm (RPM) of the combustion engine (120) when the starter motor (1 10) is activated , and

a starter motor analyzer ( 160) configured so as to define a preliminary status (S) for the start system based on said basic technical data (U , RPM),

characterized in that the test system comprises a control unit (1 70) configured so as to activate the start system only in response to a start request from an operator (OP) and , based on the preliminary status (S), to:

determi ne whether information i n addition to said basic technical data (U , RPM) is needed and , if such is the case,

execute an interactive communication process wherein the operator (OP) is called upon to i nput information (OPInp) to the control unit (1 70) in at least one process step and , based on said interactive communication process,

generate an expanded status message (TR) that describes a functional status of the start system .

2. The test system according to claim 1 , comprising at least one user interface (180) configured so as to

present information (DReq , TR) generated by the control unit (1 70) to the operator (OP), and

receive input signals (OPInp) from the operator (OP).

3. The test system according to any of claims 1 or 2, wherein the control unit (1 70) is configured so as to receive at least one sensor signal ([s,]) in addition to said basic technical data (U , RPM) and to generate the expanded status message (TR) on the further basis of said at least one sensor signal ([s,]).

4. The test system according to any of the preceding claims, wherei n the control unit (1 70) is configured so as to:

determi ne, by means of an interactive communication process with an operator (OP), whether basic conditions to allow activation of the electric starter motor (1 10) are present and , only if said basic conditions are present,

enable activation of the electric starter motor (1 10).

5. The test system according to claim 4, wherein said basic conditions incl ude the fulfillment of a start condition pertaining to an alcohol lock in the vehicle.

6. The test system according to any of claims 4 or 5, wherein said basic conductions include that the combustion engine ( 120) not be running .

7. The test system according to any of claims 2 to 6, wherei n said at least one user interface ( 180) is configured so as to receive input signals (OPInp) from the operator (OP) pertai ning to at least either of acoustical or optical signals generated by the vehicle in connection with activation of the electric starter motor (1 10).

8. The test system according to any of the preceding claims: comprising at least one temperature measuring element configured so as to measure at least one temperature related to the vehicle, and wherein

the starter motor analyzer ( 160) is configured so as to define the preliminary status (S) on the further basis of said at least one measured temperature.

9. A method for determining the function of a start system i n a vehicle, which start system is arranged so as to start a combustion engine (120) in the vehicle by means of an electric starter motor (110), which method comprises:

measuring basic technical data, including a supply voltage (U) to the electric starter motor (110) and an rpm (RPM) of the combustion engine (120), when the electric starter motor (110) is activated, and

defining a preliminary status (S) of the start system based on said basic technical data (U, RPM), characterized by activation of the start system only in response to a start request from an operator (OP) and, based on the preliminary status (S): determining whether information in addition to said basic technical data (U, RPM) is needed and, if such is the case,

executing an interactive communication process wherein an operator (OP) is called upon to input information (OPInp) to the control unit (170) in at least one process step and, based on said interactive communication process,

generating an expanded status message (TR) that defines a functional status of the start system.

10. The method according to claim 9, comprising:

presentation of generated information (DReq, TR) for an operator (OP), and

receiving of input signals (OPInp) from the operator (OP).

11. The method according to any of claims 9 or 10, comprising:

receiving of at least one sensor signal ([s,]) in addition to said basic technical data (U, RPM), and

generating the expanded status message (TR) on the further basis of said at least one sensor signal ([s,]).

12. The method according to any of claims 9 to 11, comprising: determining, by means of an interactive communication process with an operator (OP), whether basic conditions for allowing activating of the electric starter motor (110) are present and, only if said basic conditions are present,

enabling activation of the electric starter motor (110).

13. The method according to claim 12, wherein said basic conditions incl ude the fulfillment of a start condition pertaining to an alcohol lock in the vehicle.

14. The method according to any of claims 12 or 13, wherein said basic conditions include that the combustion engine (1 20) not be running .

15. The method according to any of claims 10 to 14, comprising receiving of i nput signals (OPInp) from the operator (OP) concerning at least either of acoustical or optical signals generated by the vehicle in connection with activation of the electric starter motor (1 10).

16. The method according to any of claims 9 to 1 5, comprising : measuri ng of at least one temperature related to the vehicle, and

defining the preliminary status (S) on the further basis of said at least one measured temperature.

1 7. A computer program directly downloadable to the internal memory (165) of a computer, comprising software for controlling the steps according to any of claims 9 to 1 6 when said program is run on the computer.

18. A computer-readable medium ( 165) with a program stored thereon , wherein the program is adapted so as to enable a computer to control the steps according to any of claims 9 to 16.