The mechanic encounter a variety of car failures every day, even if most of them are not so-called difficult faults, but if mechanic can persist in recording these cases and summarize them, it is believed that this will play a great role in terms of technical improvement.

Vehicle information

Model: Honda EZ

Year: 2014

Mileage: 90000KM


Fault symptom

The client reports that after the car is turned off, it has to wait for a period of time to remotely lock the car.


Diagnose process

1. Mechanic tested the car and found that the car had to wait 15s after each flameout to lock the car. The car was equipped with audio amplifier, courtesy lamp, reversing camera and LED reading lights. The above equipment was removed one by one, and the fault still exists.

2. Further testing found that when the central control lock button in the car was pressed, and the lock and unlock functions were normal, indicating that the problem was only with the remote control. The power and ground of the remote control signal receiver were measured, and the results were normal.

3. After consulting the information, it is known that the body control unit will only respond to the remote lock command if it is confirmed that the key has been removed and the door is completely closed. Observation revealed that when the key is removed, the audio indicator light is still on, and only after it is turned off, the remote lock command is responded.

4. The audio indicator is supported by the ACC power supply. After the key is removed, the ACC power supply voltage disappears after a period of time. After checking the installed equipment in the car again, it was finally found that a charger was also plugged into the cigarette lighter. This charger will discharge in the reverse direction after the ACC power is cancelled, thus causing the occurrence of residual voltage.


5. Unplug the cigarette lighter and troubleshoot.


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