The fuel pressure sensor, also known as the fuel rail pressure sensor, is used in diesel and some gasoline engines. The fuel pressure sensor is connected to the engine control unit (ECU), known as a vehicle’s central computer, and is located close to the middle of the fuel rail.
Many people think the oil pressure is responsible for keeping the engine running alone, but this is not true. The fuel pressure is equally vital and helps keep the engine running by ensuring that the fuel line and pressure are intact.
What does a fuel pump sensor do?
The latest car brands and models are equipped with fuel rail pressure sensors. The task of the fuel rail pressure sensors is to keep track of the fuel pressure inside the fuel rail, and the fuel pressure sensor helps in detecting any fuel leakage in the fuel system.
Information and data are transmitted to the engine control unit through the fuel rail pressure sensor, notifying the driver of a specific problem through the warning light.
It also notifies the driver of the quantity of fuel the vehicle engine needs. If fuel injected into the combustion chamber exceeds what the engine needs, it may worsen your fuel economy.
Where is the fuel pump sensor located?
The fuel pump sensor, a vital part of a fuel pump assembly, can be seen together with the fuel tank in the car’s rear. It also connects to the factors that deal with the evaporative emissions system (or EVAP).
The fuel rail pressure sensor could be seen inside or on top of the fuel tank. It is paramount to note that the fuel sensors in a car could number one to four.
Please note that the fuel tank differs from the fuel sensors and should not be mistaken.
Symptoms of a Bad Fuel Pressure Sensor
The fuel rail pressure sensor is a significant part of a vehicle, and when faulty, the engine control unit would not function properly. Below are the symptoms of a bad fuel pressure sensor;
1. Check Engine Light
The “Check Engine” gives a warning signal on the dashboard to notify the driver that the fuel rail pressure sensor is faulty. The sign is turned on when the engine control unit identifies a defective component that affects the vehicle engine in any way.
Don’t panic when the warning comes on, thinking your engine has developed some fault. The problem may be from a particular component disallowing the vehicle from doing its job correctly. The engine check light doesn’t directly tell you of the exact fault of your car, so of course, you may not know where the problem is coming from, except if you use a diagnostic scan tool like an OBD reader to understand the exact problem.
The most common DTC codes that tell you the fuel rail sensor has a problem are P0190, P0191, P0192, P0193, and P0194.
As a driver, immediately you get the engine check light, you can visit any auto parts store to run the scan, which is free.
2. Difficulty Starting Engine
Your engine control unit can be primarily affected if you have a faulty fuel rail sensor. When your fuel rail sensor is defective, the amount of fuel intake in your car is concerned, making it difficult for your engine to start.
When your fuel rail pressure sensor is wrong, it prevents your engine control unit (ECU) from sending the accurate fuel range to the engine, making it difficult for your vehicle to start.
It first starts with multiple attempts to crank your engine before it starts. If it is left unrepaired, the problem escalates, and it will take more shots to start the engine, and sometimes, even when you create it, it goes off immediately. It will only start again when left unattended if you repair it.
3. Weak Acceleration
If you notice that your vehicle refuses to accelerate after stepping on your gas pedal, then there must be something wrong with your fuel pressure sensor.
The fuel pressure sensor will not be able to provide accurate information to the engine control unit, which can primarily affect the quantity of fuel injected into the car’s combustion chamber.
This usually happens when your fuel rail pressure sensor has gotten wrong. In this case, your vehicle may suddenly stall while driving, and it also happens while you are not steering.
Leaving your vehicle like this unattended to is very dangerous and can harm you when driving. The least you can do in this situation is to take your vehicle to a repair shop. If, after your car is scanned and you discover that the sensor has issues, change it.
5. Bad Fuel Mileage
It would help if you did not write off lousy fuel mileage as one of the common factors affecting your fuel pressure sensor. When your fuel pressure sensor seems not working as it should, there may be a drastic reduction in your fuel economy and mileage.
When you have lousy fuel mileage, your engine control unit (ECU) will not function well and may send less or too much fuel through the fuel rail into the combustion chamber. With these inaccurate ECU calculations, you will visit the gas station more often and spend more on energy.
If you have a large vehicle, you will notice a drastic reduction in fuel economy, even more than smaller cars.
The lousy fuel mileage problem will affect how your engine performs and your entire fuel rail and fuel delivery system. This says you will spend much on fuel because your car will consume a lot.
What causes fuel tank pressure sensor failure?
Numerous factors cause fuel rail pressure sensors to fail, and they are;
Bad fuel lines
Numerous issues can cause a lousy environment inside the fuel system. When you have a clogged fuel filter or when dirty is allowed into the fuel line, it can obstruct the fuel supply line and significantly impact the fuel pressure regulator.
Defective fuel pump
When a fuel pump is weak, it can also cause a problem for the fuel rail pressure sensor. The fact that the sensor is carefully built doesn’t mean it was built to withstand a faulty fuel pump. When a part of the system has a fault, it can affect the system.
Damaged fuel tank
When a tank leaks or there is debris in the tank or too much air in the tank, it can negatively affect the fuel rail pressure sensor. A fuel rail pressure sensor can also be caused when the fuel tank is damaged.
Steps to test fuel tank pressure sensor with a multimeter
Below are the steps to test a fuel tank pressure sensor with a multimeter:
- Switch off your car.
- Make sure you disconnect the sensor.
- Proceed to start the vehicle and connect the multimeter.
- Observe and compare the reading of the multimeter to the task. When comparing them and you notice that it doesn’t match, it is clear that the sensor reading is incorrect.
- Use the test box that comes with your car to inspect all the car’s wiring under the hood
- After you have done the reading and it doesn’t match, you have to visit a technician to fix it. But even after the reading comes out good, and the wiring seems to be in perfect shape, it is still recommended that you clean the fuel-injected parts of the system.
How much is replacing a fuel pressure sensor?
If you have a problem with your fuel pressure sensor but how much it will cost to change this, then this is for you. Whether you are using a large vehicle or a small out, the prices of the fuel pressure sensor have proven to be a cost range. The average fuel pressure sensor replacement part costs between $100 and $150, while the labor costs between $100 and $200.