JPH0666196A - Self-diagnosis device for vehicle - Google Patents

Abstract

PURPOSE:To prevent the diagnosis data from being erroneously reset after a power source is inputted again. CONSTITUTION:A control unit 1 is equipped with a CPU 101 and a RAM 102 for holding the memory contents even in the case where an ignition key is cut off. The CPU 101 detects the diagnosis data necessary for analyzing the anomaly of the equipment mounted on a vehicle memorizes the diagnosis data and the anomaly detection history into the RAM 102 when the anomaly state of the on-vehicle equipment is detected. After the ignition switch is inputted again, the anomaly detection history is referred, and if the detection history exists, the renewal of the diagnosis data is prevented. Accordingly, the erroneous reset of the diagnosis data in the reinput of a power source is prevented when a power source is inputted again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle self-diagnosis apparatus which stores and holds diagnostic data necessary for abnormality analysis of in-vehicle equipment.

[0002]

2. Description of the Related Art The current electronics of vehicles is remarkable, and the equipment mounted on each part of the vehicle including the engine is
Control computers are organically connected to each other to perform complicated operations.

In this case, even if an operation abnormality of a single on-board device is detected, if data (diagnosis data) indicating the vehicle state at that time is not collected in a wide range, it is true in relation to other on-board devices. The cause is often unknown. In addition, there is a case where natural recovery occurs after a temporary operation abnormality, which is often a symptom of a complete failure, but it is difficult to find the cause by inspection after getting off the vehicle.

In view of this, in Japanese Patent Laid-Open No. 62-142849, the diagnostic data of each part of the vehicle is updated and stored in a memory that retains the contents even when the power is cut off at regular intervals, and an abnormality in the mounted equipment is detected. After that, a self-diagnosis device is proposed in which updating of the memory contents is prohibited (freeze) so that the cause of the abnormality can be accurately grasped after getting off the vehicle.

Further, in Japanese Patent Laid-Open No. 3-92564,
An apparatus has been proposed in which a control program is stored in a memory in addition to the above-mentioned diagnostic data to try to grasp the cause of the abnormality more accurately.

[0006]

By the way, in the above-mentioned conventional apparatus, when the ignition switch is cut off during the data freeze after the abnormality is detected, the diagnostic data is initialized when the ignition switch is turned on again and the control program starts. There is a problem that it is reset and the abnormality analysis becomes impossible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a vehicle self-diagnosis device in which diagnostic data is not accidentally reset after the power is turned on again.

[0008]

The structure of the present invention will be described with reference to FIG. 9. Diagnostic data detecting means for detecting diagnostic data necessary for analyzing an abnormality of an on-vehicle device mounted on a vehicle,
An abnormality detection unit that detects an abnormal state of the vehicle-mounted device, an abnormality detection history storage unit that stores the abnormality detection history of the abnormality detection unit, and retains the memory even when the ignition switch is in an OFF state; Diagnostic data storage means for storing the diagnostic data detected by the diagnostic data detection means after the abnormality of the vehicle-mounted device is detected, and retaining the storage even when the ignition switch is in an off state,
An update prohibition unit that refers to the detection history stored in the abnormality detection history storage unit after the ignition switch is turned on and prohibits the update of the diagnostic data stored in the diagnostic data storage unit when there is a detection history. There is.

[0009]

If the ignition switch is turned off while updating the data after the abnormality is detected, the diagnostic data in the storage means will be lost due to an initial reset or the like when the ignition switch is next turned on. Here, in the above-described configuration, the abnormality detection history before the ignition switch is turned on is referred to, and when there is the detection history, the update of the diagnostic data is prohibited. Therefore, the diagnostic data will not be reset accidentally.

[0010]

1 and 2, an intake pipe E of an engine E is shown.
1, a potentiometer 21 of a flow meter 31, an intake air temperature sensor 24, a throttle sensor 27 of a throttle valve 32, and a fuel injection valve 29 are provided from the upstream side.
Is equipped with a water temperature sensor 23 on the water jacket and an O2 sensor 22 on the exhaust pipe E2 of the engine E.

A control unit 1 having a built-in CPU 101 is provided, and the CPU 101 uses a data bus for the RAM 10
2. ROM 103 for storing control program, oscillation circuit 1
04, and input / output ports 105A, 105B and output ports 106A, 106B, 106C.
RAM 102 is a normal RAM for temporary storage and a standby RAM that retains its contents even when the ignition key is shut off.
It is divided into and.

The potentiometer 21, the O 2 sensor 2
2, output signals of the water temperature sensor 23, the intake air temperature sensor 24, and the throttle sensor 27 are supplied to the multiplexer 107, A / D
It is input to the input / output port 105A via the converter 108. The output signals of the cylinder discrimination sensor 25 and the rotation angle sensor 26 are input to the input / output port 105B via the waveform shaping circuit 109.

Output signals are provided to the igniter 28 and the fuel injection valve 29 via the output ports 106B and 106C and the drive circuits 112B and 112C.

When an abnormality in each of the on-vehicle devices is detected by the procedure described later, an output signal is issued to the abnormality warning means 5 via the output port 106A and the drive circuit 112A. Further, as will be described later, the diagnostic data necessary for analyzing the device abnormality is the input / output port 105B and the mutual communication circuit 11.
It is exchanged with the failure diagnosis device 4 via 0.

FIG. 3 shows an abnormality detection program for the throttle sensor 27. At S101, it is confirmed whether the throttle opening signal is in the range of 0.1V to 4.9V (S10
1, S102), if it is within this range, the fail counter is cleared and the fail flag in the normal RAM is cleared (S105, S106). On the other hand, if the time that is not within the above range exceeds 500 ms (S103), the fail flag is set as the throttle sensor abnormality (S1).
04).

FIG. 4 shows a program for setting the fail flag in the standby RAM when the fail flag is set, and is started every 65 ms. In S201, it is confirmed whether the standby RAM can be written. If the fail flag is set, a predetermined bit of the standby RAM is set (S202, S203), and it is stored that a specific device abnormality is detected.

The memory structure of the standby RAM is shown in FIG. 5, and diagnostic data such as engine speed and engine water temperature are sequentially stored at each address in the frame. An abnormality code indicating the type of abnormality is set in the head address as described later.

FIG. 6 shows a program for controlling writing to the standby RAM. The program is started every 65 ms, and in S301, it is confirmed whether an abnormal code is set, and if not set, the diagnostic data stored in the previous cycle is updated to the newly input diagnostic data (S3
02). In this state, if the fail flag is set in the predetermined bit of the standby RAM, the above abnormality code is set as an abnormality is detected (S303,
S304). When the abnormal code is set in S301, the update is prohibited and the diagnostic data is frozen.

FIG. 7 shows an initial program that is executed only once when the ignition switch is turned on. In S401, the normal RAM is initialized, and then it is confirmed whether an abnormal code is set in the frame (S402). If the abnormal code is not set, it is confirmed whether the fail flag is set in the standby RAM (S403).

The fact that the fail flag is set means that an abnormality has been detected while the ignition switch was being turned on (previous trip). Also,
The fact that the fail flag is set also means that the ignition switch has been cut off before all the diagnostic data is updated and stored after the abnormality detection. Therefore, in S404, the abnormality code is set to prohibit the update of the standby RAM, and the diagnostic data is frozen. This prevents the diagnostic data at the time of abnormality from being reset accidentally.

FIG. 8 shows a program for connecting the failure diagnosis device after getting off the vehicle and transmitting the diagnosis data, which is started every 16 ms. In S501, it is confirmed whether there is a request for frozen diagnostic data from the diagnostic device, and the diagnostic data for the requested PID is selected (S502). Here, the request PI
D is the diagnostic data requested by the diagnostic device in the ID format. For example, PID1 is the engine speed and PID2 is the vehicle speed. The selected diagnostic data is transmitted to the diagnostic device (S503).

As described above, in this embodiment, when an abnormality in the throttle sensor is detected, data indicating various vehicle states immediately after that is stored. For this reason,
By analyzing the data stored after the occurrence of the abnormality, the operating state at the time of the occurrence of the failure can be known and the cause of the failure can be easily investigated. Further, in this embodiment, the fail flag is first set in response to the abnormality detection, and then the data is updated and recorded to store the abnormality code. Then, when the ignition switch is turned on next time, the presence / absence of the fail flag is determined to determine the occurrence of an abnormality during the previous turning on of the ignition switch and prohibit the update storage of data. For this reason, even if the ignition switch is cut off during the data update after the abnormality occurs and the data update ends in the middle, the precious data updated and stored immediately after the abnormality occurred while the ignition switch was turned on the next time is stored. It is prevented from being lost after turning on the ignition switch.

In the above embodiment, the operation is described only when the abnormality of the throttle sensor occurs, but it is known that various abnormalities can be detected as the abnormality of the vehicle-mounted device. It can be implemented in combination with device abnormality detection. Also, old data may be erased before new data is stored and new data may be stored, and even if the ignition switch is cut off during data updating after an error occurs and data updating ends midway, Only data immediately after the occurrence of the abnormality can be stored. The method of updating and storing the data is not limited to the method of updating and storing every predetermined period, and may be updated and stored only when an abnormality is detected. Further, when updating and storing every predetermined cycle, a plurality of storage areas are cyclically switched and stored, and when abnormality is detected, update storage to all of these plurality of storage areas is prohibited and a freeze state is set to detect an abnormality. Not only the data immediately after, but also the process leading to the occurrence of abnormality can be analyzed.

[0024]

As described above, according to the self-diagnosis device of the present invention, the diagnostic data at the time of the previous abnormality detection will not be erroneously reset when the power is turned on again.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a self-diagnosis device.

FIG. 2 is a configuration diagram of a control unit.

FIG. 3 is a program flowchart.

FIG. 4 is a program flowchart.

FIG. 5 is a diagram showing a memory configuration of a standby RAM.

FIG. 6 is a program flowchart.

FIG. 7 is a program flowchart.

FIG. 8 is a program flowchart.

FIG. 9 is a claim correspondence diagram.

[Explanation of symbols]

1 control unit 101 CPU (diagnosis data detection means, abnormality detection means,
Update prohibition means) 102 RAM (diagnosis data storage means, abnormality detection history storage means)

Claims (1)

[Claims] 1. A diagnostic data detecting means for detecting diagnostic data necessary for analyzing an abnormality of an on-vehicle device mounted on a vehicle, an abnormality detecting means for detecting an abnormal state of the on-vehicle device, and the abnormality detecting means. An abnormality detection history storage unit that stores an abnormality detection history and retains the memory even when the ignition switch is in an off state, and an abnormality of the vehicle-mounted device is detected by the abnormality detection unit, and then detected by the diagnostic data detection unit. When there is a detection history by referring to the diagnostic data storage means that stores the diagnostic data and retains the memory even when the ignition switch is off, and the detection history stored in the abnormality detection history storage means after the ignition switch is turned on. A self-diagnosis device for a vehicle, comprising: update prohibition means for prohibiting update of the diagnostic data stored in the diagnostic data storage means. Place