JP2002014726A5 - - Google Patents

Description

[Title of the invention] Electronic control device for engine control

0006
[Means for solving problems]
In the invention according to claim 1, the control unit operates when the ignition switch is turned on to perform data calculation and control related to engine control, and is stopped when the ignition switch is turned off . The timekeeping unit operates by supplying power from a power source of a system different from that of the control unit, and measures the passage of time while the engine is stopped . In particular, the control unit indirectly or directly monitors the power supply state to the timekeeping unit, thereby determining whether or not the timekeeping unit is reset. In short, the timekeeping unit embodied in a clock IC or the like does not have a function of determining its own reset, but according to the present invention, the presence or absence of a reset of the timekeeping unit is performed by monitoring the power supply state to the timekeeping unit. Can be suitably determined by the control unit. As a result, even if the timekeeping unit is inadvertently reset, it can be recognized correctly.

Claims (6)

In an engine control electronic control unit mounted on a car and performing engine control,
A control unit that operates when an ignition switch is turned on to carry out data calculation and control related to the engine control, and stops when the ignition switch is turned off ,
The control unit is operated by power supply from a power supply different from that of the control unit, and includes a timer unit that measures the elapsed time during stop of the engine .
The electronic control unit for engine control according to claim 1, wherein the control unit indirectly or directly monitors the power supply state to the clock unit to thereby determine the presence or absence of the reset of the clock unit. The engine control electronic control device according to claim 1, wherein the control unit determines whether the timer unit is reset during a stop period of the control unit when the control unit is started. The memory has a memory for holding the stored contents by supplying power from the power supply while keeping the same as the timer and the power supply, and monitoring a drop in the power supply voltage using the data holding voltage of the memory as a threshold slightly higher than the reset voltage of the timer. An electronic control unit for engine control ,
3. The engine control electronic control device according to claim 1, wherein the control unit determines the presence or absence of reset of the timekeeping unit based on a history indicating that the power supply voltage of the memory has dropped below the data holding voltage. It has a memory which holds the stored contents by supplying power from the power supply while keeping the timekeeping unit and the power supply the same.
The engine control electronic control device according to claim 1 or 2, wherein the control unit checks data held in the memory, and determines the presence or absence of a reset of the clock unit from the check result. The engine control electronic control device according to claim 1 or 2, further comprising means for detecting a power supply voltage of the clock unit, wherein the control unit determines reset of the clock unit based on a detection result of the power supply voltage. Comprising a water temperature sensor for detecting the temperature of coolant of the engine, the elapsed time and determines engine control electronic control device a failure of the water temperature sensor and a detection value of the water temperature sensor when the engine start in the engine stop,
The engine control electronic control device according to any one of claims 1 to 5, wherein the control unit prohibits the failure determination of the water temperature sensor when it is determined that the timer unit is reset.