It is easier to judge some hard faults of automobile fuel pump (such as not working, etc.), but it is harder to judge some intermittent soft faults. In this regard, the performance of fuel pump can be judged by measuring the working current of fuel pump with digital multimeter. The specific method is as follows.
(1) Put the automobile digital multimeter in the current gear, press the function key (SELECT) to adjust to the DIRECT current (DC) gear, and then connect the two meter pens in series in the connection line of the tested fuel pump.
(2) Start the engine and press the dynamic recording key (MAX/MIN) of the digital multimeter of the car when the fuel pump is working, then the maximum and minimum current of the fuel pump can be automatically recorded. By comparing the detected data with the normal values, the cause of the failure can be determined.