Failure detecting apparatus of a control unit for a vehicle
First Claim
1. A failure detecting apparatus of a control unit for a vehicle, said apparatus detecting failures of solenoids used to control various functions of the vehicle, comprising:
- a solenoid driving circuit which selectively supplies currents to said solenoids;
an input circuit for receiving an output signal as a return signal from each of the solenoids which is in a normal operating state;
an ignition switch which outputs an engine start signal when it is turned on;
control circuit means for outputting to said solenoid driving circuit command signals which cause said solenoid driving circuit to supply currents to the solenoids in a predetermined sequence when said start signal is inputted from said ignition switch to said control circuit means, for receiving through said input circuit the return signals from said solenoids supplied with the currents, for determining that any said solenoid which fails to output a return signal in response to the application of current thereto is defective, and for outputting an alarm signal when a defective solenoid is detected; and
alarm indicating means for indicating the solenoid which is defective in response to said alarm signal from said control circuit.
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Accused Products
Abstract
A control unit for use in a vehicle includes a failure detecting apparatus for detecting failures of solenoids which are used for various kinds of controls of the vehicle. The failure detecting apparatus includes a solenoid driving circuit which sequentially supplies currents to the solenoids, and includes an input circuit which receives an output signal from each solenoid which operates normally. When a solenoid doesn'"'"'t operate normally, no output signal is returned. Therefore, a control circuit of the apparatus detects the absence of the output signal from such solenoid and thereby determines that this solenoid is defective. When the failure of a solenoid is thus detected, the control circuit outputs an alarm signal to the alarm indicator through the alarm driving circuit, the alarm signal identifying the defective solenoid. A light emitting diode corresponding to the defective solenoid may then be lit to visually indicate the failure.
27 Citations
8 Claims
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1. A failure detecting apparatus of a control unit for a vehicle, said apparatus detecting failures of solenoids used to control various functions of the vehicle, comprising:
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a solenoid driving circuit which selectively supplies currents to said solenoids; an input circuit for receiving an output signal as a return signal from each of the solenoids which is in a normal operating state; an ignition switch which outputs an engine start signal when it is turned on; control circuit means for outputting to said solenoid driving circuit command signals which cause said solenoid driving circuit to supply currents to the solenoids in a predetermined sequence when said start signal is inputted from said ignition switch to said control circuit means, for receiving through said input circuit the return signals from said solenoids supplied with the currents, for determining that any said solenoid which fails to output a return signal in response to the application of current thereto is defective, and for outputting an alarm signal when a defective solenoid is detected; and alarm indicating means for indicating the solenoid which is defective in response to said alarm signal from said control circuit. - View Dependent Claims (2, 3, 4, 5)
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6. A failure detecting apparatus for a vehicle which has a plurality of components to be controlled, comprising:
- a plurality of solenoids which are each connected to and control a respective one of said components;
a solenoid driving circuit having a plurality of outputs which are each connected to and control a respective said solenoid;
an input circuit having an input;
a plurality of diodes which each have an anode and a cathode, the anode of each said diode being connected to a respective said output of said solenoid driving circuit, and said cathodes of said diodes all being connected to each other and to said input of said input circuit; and
control means cooperable with said solenoid driving circuit and said input circuit for causing said solenoid driving circuit to sequentially produce a respective output signal at each said output thereof, and for verifying that a return signal is received at said input of said input circuit in response to each said output signal. - View Dependent Claims (7, 8)
- a plurality of solenoids which are each connected to and control a respective one of said components;
Specification