WO2008095840A1

WO2008095840A1 - Method and device for storing an error code

Info

Publication number: WO2008095840A1
Application number: PCT/EP2008/051091
Authority: WO
Inventors: Carsten Bruns; Rainer Klumpp; Andreas LÄUFER
Original assignee: Continental Automotive Gmbh
Priority date: 2007-02-05
Filing date: 2008-01-30
Publication date: 2008-08-14
Also published as: DE102007005683B3

Abstract

In order to store an error code (ERR_COD) in an error memory of a motor vehicle, when a functional error (ERR) occurs in the motor vehicle an error code (ERR_COD) which is assigned to the respective functional error (ERR) which has occurred is stored in an error memory of the motor vehicle. The stored error code (ERR_COD) in the error memory is classified as a permanent error code (ERR_COD_PER) if, after the presence of the functional error (ERR) has been confirmed, an engine check light (MIL) is made to light up on the basis of the confirmed functional error (ERR). Only when fault-free functioning of the motor vehicle has been detected with respect to the functional error (ERR) is the permanent error code (ERR_COD_PER) released for deletion, and otherwise deletion of the permanent error code (ERR_COD_PER) is prevented.

Description

200 62394 6

description

Method and device for storing an error code

The invention relates to a method and a device for storing an error code in a fault memory of a motor vehicle. When a malfunction of the motor vehicle occurs, an error code assigned to the respective malfunction occurred is stored in an error memory of the motor vehicle.

Regulations, for example in the USA, state that the malfunction must be documented when a malfunction of a motor vehicle occurs. For this purpose, an error memory is provided in each motor vehicle, in which an error code assigned to the occurred functional error is stored when the predetermined functional error occurs. Within the fault memory, the error code can assume two different states. When the malfunction occurs for the first time, the error code is given the status "Pending." If the malfunction is confirmed in a subsequent drive cycle, it receives the status "Confirmed". During an inspection or repair of the motor vehicle, the error memory, in particular the error codes, which are designated as "pending" and / or "confirmed", can be deleted.

It is the object of the invention to provide a method and a device for storing an error code which simply enables the storage of error codes which can not be erased by a clear command for erasing the error memory.

The object is solved by the features of the independent claims. Advantageous embodiments of the invention are specified in the dependent claims.

The invention is characterized by a method and a device for storing an error code in a faulty state. 200 62394 6

Lerspeicher a motor vehicle. When a malfunction of the motor vehicle occurs, an error code assigned to the respective malfunction occurred is stored in an error memory of the motor vehicle. The stored error code in the error memory is classified as a permanent error code if, after confirmed existence of the functional error due to the confirmed functional error, a lighting up of an engine control lamp is caused. Only with recognized error-free function of the motor vehicle with respect to the malfunction is the permanent error code released for erasing. Otherwise, a clearing of the permanent error code is prevented.

This makes it possible, without additional memory, for which its own memory management would be necessary, to store the permanent error codes. Furthermore, this eliminates the need for a synchronization of the error codes, as in two separate memories - one for the permanent and one for the non-permanent error codes - would be necessary. The occurrence of the function error and the confirmation of the functional error can fall into different driving cycles. The device for storing the error code may be comprised by a control unit of the motor vehicle.

The invention is explained in more detail below with reference to schematic drawings.

Show it:

FIG. 1 is a flow chart of a program for storing an error code;

Figure 2 is a flow chart of a program for clearing a permanent error code.

Elements of the same construction or function are cross-overlined with the same reference numerals. 200 62394 6

A motor vehicle comprises a device for operating the motor vehicle, in particular for operating an internal combustion engine of the motor vehicle. The device is designed to detect a malfunction ERR (FIG. 1) of the motor vehicle and to store an error code ERR_COD assigned to the malfunction ERR in an error memory of the motor vehicle. The device for storing the error code can be integrated in a control unit of the motor vehicle. The control unit is, for example, a motor control unit of the motor vehicle.

A program for storing the error code ERR COD is preferably stored on a memory unit of the device for storing the error code ERR_COD. The program for storing the error code ERR_COD is used to store the corresponding error code ERR_COD depending on the occurred functional error ERR and to classify the stored error code ERR_COD depending on a type and / or a state of the functional error ERR.

The program for storing the error code ERR COD is preferably started in a step S1, in which variables are initialized, if a fault diagnosis is currently possible.

In a step S2, it is checked whether the functional error ERR exists. If the condition of step S2 is satisfied, the processing is continued in step S4. If the condition of step S2 is not fulfilled, then step S2 is executed again.

In step S4, the error code ERR_COD associated with the functional error ERR is stored in the error memory of the motor vehicle by means of a memory command SAVE.

In a step S5, it is possible to dwell for a predefined period of time DUR. The predefined period of time DUR can, for example, only be one or a few revolutions of a course 200 62394 6

However, the predetermined period of time DUR can also correspond to the time required for a current driving cycle and / or several driving cycles. Furthermore, the previous diagnosis is preferably verified or repeated in step S5.

In a step S6, it is checked by means of a confirmation command CONF whether the functional error ERR aktuell is still present. If the condition of step S6 is satisfied, the processing is continued in a step S7. If the condition of step S6 is not satisfied, the processing is continued in step S9.

In step S7, it is checked by means of an activation check ACT, whether an engine control lamp MIL of the motor vehicle is currently caused to light up due to the operational error ERR. If the condition of step S7 is satisfied, the processing is continued in step S8. If the condition of step S7 is not met, the processing is continued in a step S10.

In step S8, the stored error code ERR_COD is classified as a permanent error code ERR_COD_PER. In other words, the stored error code ERR COD receives the status of the permanent error code ERR_COD_PER in step S8.

In step S9, the stored error code ERR COD is automatically deleted by means of a first clear command DEL 1.

In step S10, the stored error code ERR_COD is classified as a confirmed error code ERR_COD_CONF. In other words, the stored error code ERR COD receives the status of the confirmed error code ERR_COD_CONF.

In a step Sil, the program for storing the error code ERR COD may be terminated. Preferably, the pro- 200 62394 6

gram for storing the error code ERR COD processed regularly during operation of the motor vehicle.

Preferably, a program for deleting the permanent error code ERR_COD_PER is stored on the memory device of the motor vehicle. The program for clearing the permanent error code ERR_COD_PER is used to delete the permanent error code ERR COD PER, which can not be deleted by a second clear command to clear the error memory, from the error memory. The second clear command is independent of a check as to whether the corresponding or further functional error ERR is still present. Furthermore, the second cancel command is initiated from outside the motor vehicle, for example by a mechanic and / or by a diagnostic software that can access the control unit of the motor vehicle via an interface.

The program for deleting the permanent error code ERR_COD_PER is preferably started in a step S12 in which variables are initialized, if a fault diagnosis is currently possible.

In a step S13, it is read which permanent error codes ERR COD PER are stored in the error memory.

In a step S14, it is checked for each permanent error code ERR_COD_PER whether the functional error ERR currently assigned to it is still present. If the condition of step S14 is satisfied, the processing is continued again in step S12. If the condition of the step S14 is not satisfied, the processing is continued in a step S14A.

In step S14A, it is checked by means of a deletion request DEL_REQ whether an attempt was made to clear the error memory by means of the second clear command. If the condition of step S14A is satisfied, the processing is continued in step S15. Is the condition of step S14A 200 62394 6

is not satisfied, the processing is continued in a step S14B.

In the step S14B, it is checked by means of the activation check ACT, whether the engine control lamp MIL is currently caused to light up due to the operational error ERR. If the condition of step S14B is satisfied, the processing is preferably continued in the current drive cycle in step S12. If the condition of step S14B is not met, the processing is preferably in further

Driving cycles continue again in step S15. In this case, the driving cycles are registered and, for example, the processing in step S15 is continued after three error-free driving cycles relating to the malfunction ERR.

In step S15, the permanent error code ERR_COD_PER is cleared for erasing. The permanent error code ERR_COD_PER is preferably automatically cleared after the release for deletion by means of a third clear command DEL_3. Alternatively, the clear to clear may also be achieved by classifying the permanent error code ERR COD PER as non-permanent error code ERR_COD. Subsequently, the corresponding error code ERR_COD can be deleted, for example, by means of the first clear command DEL 1.

Alternatively, steps S13, S14 and S15 can be executed individually for each permanent error code ERR_COD_PER.

In step S16, the program for clearing the permanent error code ERR_COD_PER may be terminated. The program for erasing the permanent error code ERR_COD_PER is preferably executed regularly during the operation of the motor vehicle.

The invention is not limited to the specified exemplary embodiments. For example, the two programs can be implemented in one program.

Claims

200 62394 6Patent claims:

1. A method for storing an error code (ERR_COD) in an error memory of a motor vehicle, in which - when a functional error (ERR) of the motor vehicle, an error code (ERR_COD) assigned to the respective occurred functional error (ERR) is stored in an error memory of the motor vehicle,

the stored error code (ERR COD) in the error memory is classified as a permanent error code (ERR_COD_PER) if, after confirmed presence of the functional error (ERR), a motor control lamp (MIL) lights up on the basis of the confirmed operational error (ERR);

- Only when detected error-free function of the motor vehicle based on the functional error (ERR), the permanent error code (ERR COD PER) for clearing is released and otherwise a clearing of the permanent error code (ERR COD PER) is prevented.

2. Device for storing an error code (ERR COD) in a fault memory of a motor vehicle, which is designed for this purpose

to store a fault code (ERR COD) assigned to the respective fault (ERR) that has occurred in each case in a fault memory of the motor vehicle when a malfunction of the motor vehicle (ERR) occurs,

- to classify the stored error code (ERR_COD) in the error memory as a permanent error code (ERR COD PER) if, after confirmed presence of the functional error (ERR) due to the acknowledged functional error (ERR) on

Lighting up a motor control lamp (MIL) is triggered,

- Only with detected error-free function of the motor vehicle based on the functional error (ERR) the permanent error code (ERR_COD_PER) to clear and otherwise to delete the permanent error code (ERR_COD_PER) to prevent.