2010-03-15
According to customer feedback, itKomatsu 220-7The excavator experienced engine failure to shut down, abnormal CPU alarm, and engine idle at over 700 revolutions per minute.
After on-site inspection, the after-sales diagnosis G-1 and G-2 data are normal. The voltage from the computer board to the stepper motor is normal, and the resistance value of the stepper motor itself is normal. After making adjustment A, the engine returned to normal, but when the key switch was turned off and the engine was restarted, the idle speed was over 1400 revolutions per minute. The key switch could not turn off the engine, and the CPU alarm was abnormal. When the key switch was turned off again and the engine was started, the engine speed was around 2200 revolutions per minute at idle, and the engine could not turn off and the CPU alarm was abnormal. The occurrence of this phenomenon is likely related to both the computer board and the stepper motor.
After replacing the stepper motor and making adjustment A, the engine can shut down normally, the CPU abnormal alarm is eliminated, and the machine works normally.
Send your inquiry directly to us
