The mileage (MAXIMA) car with a mileage of over 206 thousand km. User reflection: when the car turned on the ignition switch after a refueling, it was found that the fuel meter pointer still indicated that it was close to the "0" position, but the fuel tank was actually filled. Troubleshooting: (1) fault cause analysis of the vehicle's fuel meter is electromagnetic, the sensor is a slide resistance potentiometer, the fuel meter does not indicate the amount of oil (always indicating 0) of fault reasons: 1) the fuel meter circuit has a fault, such as the power line between the power terminal and the point fire switch between the fuel indicator, or the circuit breakage, or There is a short circuit between the fuel gauge and the sensor. 2) the inner coil of the fuel meter has a circuit breaker. 3) the slide resistance in the sensor is short circuited. (2) the fault maintenance method unplugs the wire plug on the fuel level sensor, and when the ignition switch is connected, the fuel meter pointer still indicates the "0" position, which indicates that the fault is not caused by the internal short circuit of the sensor. Check the voltage of the power terminal of the fuel indicator. When the ignition switch on (ON), the battery voltage is normal; the connection of the fuel indicator connection sensor is removed and the ignition switch is connected. If the fuel indicator is good, the pointer should point to the oil full position, but the pointer still indicates the "0" position, indicating the fault. Inside the fuel indicator. (3) replace the new fuel indicator with fault handling measures, indicating the position of full oil (full tank) and troubleshooting. Fault analysis: there are two coils in the electromagnetic fuel indicator, one is in series with the fuel level sensor, and the other is parallel to the sensor. When the current of the parallel coil is large (not much different from the current of the series coil), the needle points to the position full of oil. With the decrease of fuel level in the fuel tank, the resistance of the sensor decreases, and the current of the parallel coil also decreases, indicating that the oil quantity indicated by the indicator is also reduced. Therefore, if the connecting wire on the fuel level sensor is removed and the needle is immediately placed into the full oil position, it is sure that the fault must have a short circuit fault inside the sensor.