Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Fuel Level Sensor Unit, Fuel Pump and FPCM (Fuel pump control module)
FUEL PUMP
The low pressure fuel pump build into the fuel tank. The ECM turns the fuel pump relay ON/OFF and controls the low-pressure fuel pump. The low pressure fuel pump is integrated with a fuel pressure regulator and a fuel filter. When the ignition switch is turned ON, the fuel pump operates for 1 second to start the engine. During cranking and while the engine is running, the fuel pump relay turns ON to operate the low pressure fuel pump, and gasoline inside the fuel tank is sent to the fuel line after passing through the fuel filter. When the fuel pressure in the fuel line reaches or exceeds the specified pressure, the low pressure fuel regulator opens, and the gasoline in the fuel line returns to the fuel tank, lowering the fuel pressure.
| Vehicle condition | Fuel pump operation |
|---|---|
| Ignition switch is turned to ON | Operates for 1 seconds |
| Engine cranking and running | Operates |
| When engine is stopped | Stops in 1.5 seconds |
| Except as shown above | Stops |
FUEL LEVEL SENSOR
The fuel level sensor
is mounted in the fuel level sensor unit.
| Fuel pump control module (FPCM) |
The sensor detects a fuel level in the fuel tank and transmits a signal to the combination meter. The combination meter sends the fuel level sensor signal to the ECM via the CAN communication line. It consists of two parts, one is mechanical float and the other is variable resistor. Fuel level sensor output voltage changes depending on the movement of the fuel mechanical float.
FPCM (Fuel Pump Control Module)
The fuel pump control module (FPCM)
controls the fuel pump to satisfy a discharge rate suitable to a driving condition, according to the control from ECM. This reduces the electricity consumption of fuel pump during low load.
| Fuel level sensor |
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.