JPS5985503A - Self-diagnosing device of engine controller for car - Google Patents

Abstract

PURPOSE:To enable always diagnosis for a new situation by providing a timer to deliver a self-diagnosis start signal for every fixed time and carrying out rediagnosis for every fixed time. CONSTITUTION:The input or output signal of a control part 1 in a control unit is supplied to a monitor circuit 2 for monitor. Then a fault signal is delivered from a circuit 2 when said input or output signal gets out of a normal range in a specific operation state. A timer 3 detects the specific operation state from another input signal and then integrates the time as long as the specific operation state is set. A discriminating circuit 4 is actuated during the integration of time to count the fault signals of the circuit 2. When the integrated time of the timer 3 exceeds the set value, the discrimination of the circuit 4 is urged. That is, a normal or abnormal state is discriminated in accordance with the count value of fault signals during the integration of time. Then the result of this discrimination is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a self-diagnosis device for an automobile engine control device.

Conventionally, in automobile engines equipped with electronically controlled fuel injection devices, etc., input and output signals of the control unit, such as signals from various sensors that detect engine operating conditions, are diagnosed by the control unit itself. Some vehicles are equipped with a self-diagnosis device that determines whether or not the signal system is in a normal concave circle based on the operating conditions at that time, and displays whether or not there is an abnormality in the signal system.

However, conventional self-diagnosis devices generally perform self-diagnosis only when the power is turned on when starting the engine, and such a one-time self-diagnosis cannot detect problems that occur during operation. Not only was it not possible to detect abnormalities that occurred, but it was also impossible to display when the abnormality was resolved midway through. Also, depending on the diagnostic item,
Accurate diagnosis was sometimes not possible when the warm-up condition was abnormal, such as when starting.

The present invention has been made with the aim of solving such conventional problems, and includes a timer that issues a self-diagnosis start signal at fixed intervals (for example, about 10 minutes), and re-diagnosis is performed at fixed intervals. This is how it was done.

Hereinafter, embodiments will be described according to the drawings.

In FIG. 1, an input signal input to the control section 1 in the control unit or an output signal output from the control section 1 is input to a monitor circuit 182 and monitored there. When the signal falls outside the range of a normal signal in a specific operating state (diagnosable region), this is regarded as abnormal, and the monitor circuit 2 issues an abnormal signal.

A timer 3 is installed to which input/output signals other than the signal from the control section 1 are input.This timer 3 detects a specific operating state based on the other input/output signals,
Time is accumulated as long as the vehicle is in a specific operating state (see Figure 2). Then, the determination circuit 4 is operated during this integration time.

The determination circuit 4 counts abnormal signals from the monitor circuit 2 during this integration time. Therefore, abnormal signals outside of specific operating conditions are not integrated.

When the cumulative time of the timer 3 exceeds the set time, the determination circuit 4 is prompted to make a determination. That is, it is determined whether the state is normal or abnormal according to the numerical value of the count value of the abnormal signal during the integration time, and the determination result is displayed. At the same time, initial settings are performed and self-diagnosis starts again.

In this embodiment, the timer only counts the time when the conditions for diagnosis are met, that is,
Since the diagnosis is performed after the conditions for determining normality and abnormality are established, misdiagnosis can be prevented.

As explained above, according to the present invention, re-diagnosis is performed at fixed intervals using a timer, so even if it is once diagnosed as normal, by re-diagnosing it, a new A situation can always be diagnosed. It will be done.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a time chart of the same. 1...Control unit 2...Monitor circuit 3...
Timer 4... Judgment circuit patent applicant Fujio Sasashima, patent attorney for Nippon Denshiki Co., Ltd.

Claims (1)

[Claims] In a self-diagnosis device for an automobile engine control device that diagnoses the input/output signals of the control unit by itself based on the self-diagnosis start signal and displays whether there is an abnormality in the signal system, the self-diagnosis start signal is sent at regular intervals. A self-diagnosis device characterized by being equipped with a timer that emits a signal.