Diagnostic system for a motor vehicle

Abstract

The invention relates to at least one electronic control unit and / or diagnostic tester for a motor vehicle-diagnosis system. The electronic control unit for a motor vehicle according to the invention is equipped with: a diagnostic module for identifying and storing errors; a decision module by means of which a defined error reaction is assigned to each identifiable error and a defined customer complaint status is assigned to the error reaction; and a generation module for generating defined error states. The error states can be generated for each error stored in the error memory and transmissible to a diagnostic tester outside the vehicle together with the error log, such that all customer complaint states assigned to the error can be identified from the error log in the diagnostic tester. The decision module is likewise provided for a diagnostic tester matching this and having a transmission interface to the at least one electronic control unit.

Description

Technical Field

[0001] The present invention relates to a diagnostic system for error diagnosis in a motor vehicle. Background Art

[0002] For example, such diagnostic systems are discussed in EP 0 629 774 B1.

[0003] Diagnostic systems and diagnostic methods for motor vehicles have been known for many years. The motor vehicle includes a controller inside the vehicle with self-diagnostic capabilities for checking various electronically controlled systems. Among them, an error memory set in the controller is scanned by a diagnostic instrument (also called a "tester") outside the vehicle and connected to the motor vehicle. By means of the tester or the diagnostic instrument, the inspection steps to be executed can also be predetermined.

[0004] Here, the controller inside the vehicle with self-diagnostic capabilities usually checks its input and output signals (on-board diagnosis). With the data checked, in case of an identified error, the error information can be saved in a non-volatile memory, and the non-volatile memory can be read in the workshop by means of the tester.

[0005] Possible error information is, for example, the loss of a certain sensor signal. However, this error can be attributed to various possible causes: for example, a break at any position in the cable harness, or due to an incompletely connected plug, or due to a damaged input circuit in the controller that is allocated to the sensor signal.

[0006] The inspection steps predetermined based on the error information are used to find out the exact error cause. Because in practice, although the inspection steps are implemented, the components to be considered for a certain error, especially the electronic controller, are usually replaced out of suspicion, resulting in unnecessarily high repair costs. Moreover, intact components are sent for repair. Summary of the Invention

[0007] The object of the present invention is to ensure more targeted error diagnosis for motor vehicles, especially in the workshop.

[0008] The object is solved by an electronic controller for a motor vehicle, a diagnostic tester, a diagnostic system, and an error memory state according to the present invention.

[0009] The present invention relates to at least one electronic controller and / or diagnostic tester for a motor vehicle-diagnostic system.

[0010] The electronic control unit for a motor vehicle according to the present invention is equipped with: a diagnostic module for identifying and storing errors; a decision module, by means of which a determined error response is assigned to each identifiable error and a determined customer complaint status is assigned to the error response; and a generation module for generating a defined error status.

[0011] The error status can be generated for each error set in the error memory and transmissible to a diagnostic tester outside the vehicle along with the error log in such a way that all customer complaint statuses assigned to the error can be identified from the error log in the diagnostic tester.

[0012] The decision module is also provided to a diagnostic tester matching this and having a transmission interface to the at least one electronic control unit. The decision module can for example be configured as a programmed table structure, and it can either be stored in the diagnostic tester and likewise in the control unit, or it can be transmitted from the control unit to the diagnostic tester. The diagnostic tester contains an analysis unit, by means of which the assigned customer complaint status can be identified from a defined error status transmitted by the control unit for one error or multiple errors with the aid of the decision module.

[0013] Preferably, the number of the determined customer complaint statuses is (significantly) smaller than the number of the determined error responses.

[0014] The present invention is based on the following recognition:

[0015] The tester outside the vehicle contains for example an analysis device, by means of which the information extracted from the error memory is analyzed and presented in order to accurately locate the error. The error memory indicates for example the error number, the error type and the operating parameters present at the time of the error occurrence. The error type can for example be a short circuit to ground, a short circuit to the positive pole or an open circuit. The error number indicates for example which component or which circuit is faulty. However, this error number is only functional error information, which although can define the error location, however cannot accurately explain the error cause.

[0016] The present invention is developed by using a new scheme of an emergency operation manager. With the concept of the new emergency operation manager, a more accurate so-called "precise identification" (= pointing out the error cause) must be achieved.

[0017] According to the prior art, when a customer with a complaint comes to the workshop (e.g., "My vehicle no longer accelerates correctly", "The engine start-stop automatic device no longer works properly"), the workshop can read the error memory. However, the error memory does not contain more accurate information about what effects the error has on the vehicle and its behavior. Therefore, in the workshop, the following information is missing in multiple error memory entries, and with this information, the error memory can be addressed in view of the complaint. Partially, extensive documentation has to be consulted to check which of the errors might have caused the customer complaint.

[0018] The present invention is based on the fact that error memory entries (error: = "FS_y") are associated with different error reactions (error reaction: = "FR_x") inside the controller. This association is implemented as a first table structure and is called horizontal interlocking here. The horizontal interlocking for all errors is specified in a so-called horizontal interlocking matrix ("QVM"). The QVM can be different for one vehicle after another. However, the current QVM is always stored in a controller with self-diagnostic capabilities (e.g., engine controller, transmission controller, brake controller, etc.). According to the invention, there is a second table structure, according to which defined customer perception states are assigned to different error reactions in the sense of a complexity-reducing block formation, and the customer perception states also correspond to the customer-perceivable effects of the error reaction. Furthermore, according to the invention, the two table structures are directly available in the workshop as additional information for reading from the controller with the aid of a diagnostic device (tester). The present invention enables the workshop to directly access the relevant two table structures and thus quickly process customer complaints, which are in the form of defined customer complaint states ("FZD_i"), e.g., FZD_1 = "My vehicle accelerates incorrectly" or FZD_2 = "The engine start-stop automatic device no longer works properly", because it is directly visible to the workshop which error (FS_y) has led to a specific customer complaint state (FZD_i). The transmission of information takes place via a known tester interface or through another external vehicle error memory environment. The two above-mentioned table structures will be collectively referred to as the decision module below. Description of the Drawings

[0019] The present invention will be explained in more detail with the aid of an embodiment. In the figures:

[0020] Figure 1 shows the most important components according to the invention in an electronic controller,

[0021] Figure 2 shows the most important components according to the invention in a tester, and

[0022] Figure 3Shows an example of a decision module based on the first and second table structures according to the present invention. Detailed Description

[0023] Figure 1 Shows the most important components according to the present invention in the electronic control unit 1, which has a diagnostic module 2 for identifying and storing errors FS_y and a decision module EM.

[0024] Through the corresponding implementation of the electronic control unit 1, especially in view of the diagnostic module 2 and the decision module EM, according to the present invention in terms of the development solution, the determined error reactions (FR_x; where the subscript x = 1, 2, 4,...) are assigned on the one hand to the defined errors (FS_y; where the subscript y = 1, 2, 4,...) and on the other hand to the known customer complaints in the form of defined customer complaint states (FZD_i; where the subscript i = 1, 2, 4,...). The assignment relationship is provided not only in the electronic control unit 1 by means of the decision module EM but also in the diagnostic tester 4 ( Figure 2 ). The electronic control unit 1 can transmit the assignment relationship each time the tester is connected for storage in the diagnostic tester 4.

[0025] In the electronic control unit 1, it is preferably checked whether the determined error FS_y triggers one or more of the predetermined error reactions FR_x, which in turn lead to a defined customer complaint state FZD_i. If this is the case, the error memory state "State_EM" defined according to the present invention is output on the diagnostic tester 4 in the workshop.

[0026] Preferably, the new error memory state "State_EM" is a binary code with a predetermined number of bits, where each bit is assigned to a possible customer complaint state (FZD_i).

[0027] In Figure 2 is schematically shown a diagnostic tester 4 that can be connected to the electronic control unit 1. The diagnostic tester 4 is preferably constructed such that for the known bit occupancy (Bit - Belegung) of the error memory state "State_EM" for the diagnostic tester, the diagnostic tester identifies the customer complaint state FZD_i by the bit ("1") set on a certain bit position.

[0028] Figure 3Shows an example for a possible decision module EM, which is a total table structure. Through this total table structure, a determined error response FR_x is assigned to the error FS_y (on the QVM), and a determined customer complaint status FZD_i is assigned to the error response FR_x. Through the customer complaint status FZD_i (the number of which is less than the number of error responses FR_x), block formation ("clustering") for iteratively and more quickly locating the error occurs.

[0029] It is predefined by the development plan, for example, that the error response FR_1 results in a relatively low torque limit, FR_2 results in a relatively high torque limit, FR_3 results in a relatively low speed limit, and FR_4 results in a relatively high speed limit. These FR_y correspond to all the customer perceptions "My vehicle does not accelerate correctly" or the customer perception state FZD_1.

[0030] FR_5, for example, results in a forced engine start, and FR_6 results in preventing engine stop. These FR_y correspond to the customer perception "The engine start-stop automatic device no longer works properly" or the customer perception state FZD_2.

[0031] For example, FZD_1 is assigned to bit "bit 1" of the error memory state "state_EM", and FZD_2 is assigned to bit "bit 2". Bit 1 is thus assigned to the customer perception state FZD_1 "My vehicle does not accelerate correctly", and bit 2 is assigned to the customer perception state FZD_2 "The engine start-stop automatic device no longer works properly".

[0032] If, for example, an error FS_y with the error response FR_6 occurs and the error memory of the electronic control unit 1 is set, the customer's description in the workshop will be: "The engine start-stop automatic device no longer works properly".

[0033] The workshop now reads the error memory using the diagnostic tester 4 as standard and can check according to the invention whether bit 2 has been set ("1") in the error memory state "state_EM". Since this is the case in the example, targeted error elimination measures are started here, in such a way that first all the error FS_y that are set and lead to the customer perception state FZD_2 are processed.

[0034] Through the cross-interlock matrix QVM or the decision module EM, it is thus possible to start from the more general customer perception wishes and return to the details of the error response FR_x and ultimately handle the error cause.

Claims

1. An electronic control unit (1) for a motor vehicle, the electronic control unit comprising a diagnostic module (2) for identifying and storing errors; a decision module, the decision module comprising a first table structure and a second table structure, a defined error response being assigned to each identifiable error by means of the first table structure, and a defined customer complaint status being assigned to the error response by means of the second table structure; and a generation module (3) for generating a defined error status, the error status being able to be generated for each error set in an error memory and transmissible to a diagnostic tester (4) external to the vehicle together with an error log, such that all customer complaint statuses assigned to the error can be identified from the error log in the diagnostic tester (4).

2. A diagnostic tester (4) having a transmission interface for the electronic control unit (1) according to claim 1, a decision module being provided in the electronic control unit as well, the decision module comprising a first table structure and a second table structure, a defined error response being assigned to each identifiable error by means of the first table structure, and a defined customer complaint status being assigned to the error response by means of the second table structure, the diagnostic tester having an analysis unit by means of which the assigned customer complaint status can be identified from the defined error status transmitted by the electronic control unit (1) of the error.

3. A diagnostic system, comprising the electronic control unit (1) according to claim 1 and / or the diagnostic tester (4) according to claim 2, characterized in that, The number of the defined customer complaint statuses is less than the number of the defined error responses.

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