JP2901997B2 - Vehicle failure diagnosis device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention provides a test signal to a control unit such as an engine control unit provided in a vehicle-mounted electronic control system for controlling a vehicle-mounted electronic control device.
The present invention relates to a vehicle failure diagnosis device including a tester for diagnosing a failure in a vehicle-mounted electronic control system.

<< Conventional technology >> As for a vehicle failure diagnosis device, for example,
No. 63-135250, and a control unit (eg, an engine control for electronically controlling an engine) that controls a vehicle-mounted electronic component such as various switches and sensors. There is also known a vehicle failure diagnosis device configured by connecting a tester for failure diagnosis to a unit or the like). When performing a failure diagnosis using such a vehicle failure diagnosis device, for example,
In the fault diagnosis of the power relay, which is one of the switches controlled by the engine control unit, a test signal is sent from the tester to the control unit to turn the power relay on and off continuously, and then the power relay is turned on and off. Diagnosis is made by judging the situation from the mechanical intermittent sound of the power relay.

<< Problems to be Solved by the Invention >> However, in the case of a vehicle equipped with a plurality of on-vehicle electronic control devices such as a plurality of fuel pumps each independently driven by a parallel electric circuit, the configuration of the electric circuit A power supply relay is provided in each of the branch circuits formed by branching in correspondence with each of the plurality of fuel pumps,
It is configured with a circuit opening relay as another switch that integrates the power relays in front of these branch circuits, and when driving the fuel pump, the circuit control relay and the power relay are simultaneously turned on from the engine control unit. In some cases. If a circuit configuration is used that turns on the circuit opening relays that are in series with the power supply relays of each branch circuit at the same time as the power supply relays, the tester from the tester to the engine control unit diagnoses the circuit opening relays for failure. When the circuit opening relay is turned on and off by transmitting the test signal of, the power supply relay of the branch circuit is turned on and off in synchronization with the circuit opening relay due to the configuration of the engine control unit. There is a problem that the fuel pump driven and controlled by the power supply relay is operated together, and the intermittent sound of the circuit opening relay is masked by the operation sound of the fuel pump, making it impossible to perform a fault diagnosis by hearing.

The present invention has been made in view of the above background, and an object of the present invention is to provide a vehicle failure diagnosis device that can easily perform failure diagnosis of a plurality of switches in a serial relationship.

<< Means for Solving the Problems >> The present invention provides a test signal for failure diagnosis of the on-vehicle electronic control system to the on-vehicle electronic control system including the control unit for controlling the on-vehicle electronic control device. In the vehicle failure diagnosis device configured by connecting a tester for transmitting a plurality of, the vehicle-mounted electronic control system is connected in series between a power supply and the vehicle-mounted electronic control device, a plurality of on-off by the control unit A switch, and prohibiting the operation of any one of the plurality of switches in response to diagnosing one of the plurality of switches with a test signal transmitted from the tester via the control unit at the time of failure diagnosis It is characterized by having a cancellation means.

Diagnosis of the failure of the switch is performed at least by an operation sound of the switch according to the test signal.

In addition, the plurality of switches connected in series between the on-vehicle electronic control device and the power supply are respectively connected to the plurality of on-vehicle electronic control devices arranged in parallel, and switches in a parallel relationship with each other; And a single switch in series with each of the switches in parallel.

<Operation> With the configuration described above, even if a plurality of switches provided between the power supply and the on-vehicle electronic control device and turned on and off by the control unit are in a serial relationship, the fault-diagnostic switch has a serial relationship. Since the operation of one of the other switches is prohibited by the canceling means, each switch can be independently diagnosed by the test signal transmitted from the tester. For example, the operation sound of the switch corresponding to the test signal is confirmed by hearing. By doing so, the failure diagnosis of the test target switch can be performed. This makes it possible to easily diagnose the failure of the switches in a serial relationship.

Further, in the case of a series connection in which a plurality of switches connected in parallel to the on-vehicle electronic control devices and connected in parallel with each other are collectively connected to another single switch connected to the power supply in a serial relationship. Also, each switch can be independently diagnosed by prohibiting the operation of each switch in a parallel relationship by the canceling means.

<< Embodiment >> An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a preferred embodiment of a vehicle failure diagnosis device according to the present invention.

In the figure, reference numeral 1 denotes a tester for failure diagnosis, and 2 denotes an engine control unit (hereinafter abbreviated as ECU) exemplified as a control unit provided in the vehicle-mounted electronic control system.

The tester 1 is connected to the ECU 2 by a communication path 4 via a serial interface 3 and is capable of transmitting a test signal and receiving various information such as a response to the test signal. Is transmitted and received.

The ECU 2 is connected to a large number of sensors 5 and relays 6 as switches, which are arranged in various parts of the engine (not shown). The sensors 5 and the relays 6 are integrated by the ECU 2 to constitute an on-vehicle electronic control system. Various controls of the engine are performed by the procedure.

At the time of failure diagnosis, a test signal such as a drive or stop command for various relays 6 is transmitted from the tester 1 side to the ECU 2 side, and various sensors 5 indicating the operation status of the electronic control system in response to these test signals are detected. The ECU 2 is configured to return a response such as a signal from the ECU 2 to the tester 1 and to transmit / receive information to / from each other through two-way communication to diagnose a failure of the electronic control system.

FIG. 2 is a configuration diagram showing a portion of the vehicle failure diagnosis device shown in FIG. 1 according to the present invention.

The present invention basically includes a control unit (ECU2 in the present embodiment) of a vehicle-mounted electronic control system including a sensor 5 and a relay 6 for controlling a vehicle-mounted electronic control device such as a fuel pump 62. In the vehicle failure diagnosis device configured by connecting a tester 1 that transmits a test signal for failure diagnosis of the vehicle, an on-vehicle electronic control system has a power supply (shown as battery power B in the figure) as shown in FIG. ) And a fuel pump 62 connected in series and turned on and off by the ECU 2 (in FIG. 2, the relay 6 of FIG. 1 is shown as a circuit opening relay 60 and a power supply relay 61 in a series connection relationship). )) And one of the other relays 60, 61 in response to diagnosing one of the plurality of relays 60, 61 with a test signal transmitted from the tester 1 via the ECU 2 at the time of failure diagnosis. 61 works It is configured to include a canceling means for inhibiting, canceling means tester 1
Alternatively, it is realized on a software program of a computer constituting the ECU 2.

As shown in the figure, a plurality of fuel pumps 62 provided as on-vehicle electronic control devices are provided with a power supply relay 61 in a circuit branched in parallel and a circuit opening disposed in front of the power supply relay 61 and in series with each power supply relay 61. It is controlled by the ECU 2 indirectly via the relay 60. That is, each fuel pump 62 is connected to one end of the intermittent contact of the power relay 61, and the other end of the intermittent contact of the power relay 61 is collectively connected to one end of the intermittent contact of the circuit opening relay 60. Connected. The other end of the intermittent contact of the circuit opening relay 60 is connected to a battery (not shown).
And each relay coil of the power supply relay 61 is connected to the ECU 2. As a result, the battery power B is supplied to the fuel pump 62 via the respective intermittent contacts of the circuit opening relay 60 and the power supply relay 61, and the respective intermittent contacts are turned on / off by the ECU 2.

FIG. 3 is a flowchart for explaining the operation of the present invention.

When a test signal for the circuit opening relay 60 is output from the tester 1 side, that is, when a test signal for turning on / off the intermittent contact of the circuit opening relay 60 for failure diagnosis of the circuit opening relay 60 is transmitted from the tester 1 side (S1). ), Prohibits the ON control of the power supply relay 61 which is in series with it (S2).

Therefore, if the circuit opening relay 60 was controlled on / off as usual,
Are in a series relationship, the power supply relay 61 is also turned on and off, and this activates the fuel pump 62.According to the above-described flowchart,
In the failure diagnosis of the circuit opening relay 60, the ON control of the power supply relay 61 is prohibited, so the fuel pump 62
Is not activated, thereby making it easy to confirm the intermittent sound of the circuit opening relay 60, and it is possible to easily perform a fault diagnosis by hearing. Also, at the time of failure diagnosis, the fuel pump 62
Is not started, so that unnecessary battery consumption can be prevented.

In particular, in the case of a series connection in which a plurality of power supply relays 61 which are installed in correspondence with a plurality of fuel pumps 62 and are in a parallel relationship are collectively connected to a circuit opening relay 60 in a series relationship as in the above embodiment. However, by prohibiting the ON control of the power supply relays 61 in a parallel relationship, the circuit opening relay 60 can be handled independently, and its failure diagnosis can be easily performed.

In the failure diagnosis of the power supply relay 61, the diagnosis is executed by reversing the target in a similar flowchart, that is, prohibiting the ON control of the circuit opening relay 60.

<< Effects of the Invention >> As described in detail in the embodiments above, according to the vehicle failure diagnosis apparatus according to the present invention, a plurality of on / off control units provided between a power supply and a vehicle-mounted electronic control device are provided. Even if these switches are in a serial relationship, at the time of failure diagnosis, the operation of the other switch in the serial relationship is prohibited by the canceling means, so that each switch is independently diagnosed by a test signal transmitted from the tester. For example, by audibly confirming the operation sound of the switch corresponding to the test signal, the failure diagnosis of the switch to be tested can be performed, and the failure diagnosis of the switches in a serial relationship can be easily performed. .

Further, this is the case of a series connection in which a plurality of switches connected in parallel to each other and connected in parallel with each other and connected in parallel with one another to a single switch connected to a power supply are connected together. However, by prohibiting the operation of each switch in a parallel relationship by the canceling means, each switch can be independently diagnosed, and the failure diagnosis of the switch can be easily performed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a vehicle failure diagnostic device according to the present invention, FIG. 2 is a configuration diagram showing a portion of the vehicle failure diagnostic device shown in FIG. 1 according to the present invention, and FIG. It is a flowchart explaining an effect | action. 1 Tester 2 Control unit (ECU) 60 Circuit opening relay 61 Power relay 62 Fuel pump B Battery power

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Taketo Ishida 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (56) References JP-A-63-243832 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) G01M 17/00-17/10

Claims (3)

(57) [Claims] 1. A tester for transmitting a test signal for diagnosing a failure of the vehicle-mounted electronic control system is connected to the control unit of the vehicle-mounted electronic control system having the control unit for controlling the vehicle-mounted electronic control device. In the vehicle fault diagnosis device configured, the on-vehicle electronic control system is connected in series between a power supply and the on-vehicle electronic control device, and has a plurality of switches that are turned on and off by the control unit. Canceling means for prohibiting the operation of any one of the plurality of switches in response to diagnosing one of the plurality of switches with a test signal transmitted from the tester via the control unit. Fault diagnosis device for vehicles. 2. The failure diagnosis apparatus for a vehicle according to claim 1, wherein the failure diagnosis of the switch is performed at least by an operation sound of the switch according to the test signal. 3. A plurality of switches connected in series between the on-vehicle electronic control device and the power supply, the plurality of switches being connected to the plurality of on-vehicle electronic control devices, respectively, and being in parallel with each other. 3. The vehicle fault diagnosis apparatus according to claim 1, further comprising a single switch connected to the power supply and connected in series with each of the switches in parallel.