The fuel system is a major part of the engine. It consists of a fuel pump, fuel tank, fuel injector, and fuel rails. The fuel injection system has the responsibility to supply fuel properly to the engine. The fuel rail is the most important part of the fuel system. The main function of the fuel rail is to supply fuel throughout the system. This article mainly explains the bad fuel rail pressure sensor symptoms, causes, and replacement cost.
What Is a Fuel Rail?
A fuel rail is a high-pressure fuel line that properly supplies fuel to the fuel injector in an IC engine.
It is a vital part of the fuel injection system and is essential for the stable fuel supply to the injector. The fuel rails need proper care and maintenance for proper operation. If they clog, they can’t properly supply fuel to the fuel engine; due to that, your engine may damage or clog.
Fuel rails are most commonly used in the latest direct-injection petrol engines to attain maximum fuel efficiency and reduce emission rates.
The use of this technology is increasing day by day to improve engine performance and fuel economy.
What is a Fuel rail Pressure Sensor?
The fuel rail pressure sensor is a part of the fuel injection system used to measure the fuel pressure in the fuel rails. It is also known as a fuel pressure sensor.
The fuel pressure sensor is installed near the center of the fuel rail and is connected to the vehicle’s central computer (i.e., Engine Control Unit).
Many diesel engines and some petrol engines use fuel rail pressure sensors (often referred to as fuel pressure sensors).
As the sensor measures the pressure of the fuel rails, it sends this information to the powertrain control module (PCM), which utilizes it to adjust the timing and fuel economy of the vehicle.
What is the function of a Fuel Rail Pressure Sensor?
The main function of the fuel rail pressure sensor is to continuously measure the fuel pressure in the fuel rails. When the sensor measures the fuel pressure inside the rails, it sends this collected data to the PCM.
When the PCM receives data from the sensor, it analyzes the data and makes reasonable changes to the timing and amount of the fuel being injected. This sensor helps to improve the performance of the engine in the existing operating conditions.
All vehicle manufacturers try to manufacture the best environmentally-friendly vehicles, which is a demand of current environmental conditions. In this case, the fuel rail sensor plays a big role in maintaining the emission rate and fuel economy of your vehicle.
Symptoms of a Bad Fuel Rail Pressure Sensor
A faulty or bad fuel rail sensor has the following major signs:
1) Check Engine Light
The check engine warning light on the vehicle dashboard starts to illuminate if the fuel pressure sensor fails. This light only illuminates when the ECM or PCM senses a problem with the vehicle that is disturbing the engine performance.
This does not necessarily mean that the engine itself has a problem, but it may also represent that something else in the vehicle has a problem that stops the vehicle from working properly.
You may not know at first that it is a fuel rail pressure sensor, but you can usually identify the problem with a diagnostic scan tool.
P0194, P0193, P0192, P0191, and P0190 are the most commonly used trouble codes that indicate problems with the fuel pressure sensor.
2) Hard Starting Conditions
When the fuel pressure sensor of your vehicle becomes faulty, it doesn’t send the correct information to the powertrain control module (PCM).
When the PCM receives wrong information from the sensor, it doesn’t properly regulate the fuel injection rate and ignition timing. This makes starting the vehicle difficult. In such a situation, you must immediately contact the technician and ask him to fix the problem.
3) Poor Acceleration
As you press the speed accelerator pedal and your vehicle doesn’t run according to your requirements, this problem may occur due to a defective fuel pressure sensor.
In such a situation, the PCM cannot properly send the signal to the fuel system because the information it receives from the sensor is inaccurate. In such conditions, your ECM (engine control unit) doesn’t know how to meet your engine’s fuel needs.
4) Engine Stalling
If your vehicle has a bad fuel rail pressure sensor, the engine may start to generate stalling issues. In such a situation, your engine may suddenly stop while driving. It can also remain in idle mode.
This problem will make your driving very hard and dangerous. Therefore, you must fix this problem as soon as possible.
5) Poor Fuel Economy
A reduction in fuel economy is one of the clear symptoms of a bad fuel rail pressure sensor.
When the fuel pressure sensor goes bad, your vehicle’s powertrain control module can either deliver an excessive amount of fuel or insufficient fuel into the combustion chamber via the fuel rail. This will result in a noticeable increase in trips to the gas station and greater expenses.
Individuals with larger vehicles will typically experience a more pronounced decrease in fuel efficiency. For example, the impact on the fuel economy of a Duramax engine will be more conspicuous compared to a vehicle like the Honda Civic.
6) Limp Mode
The manufacturers incorporate a limp mode system into vehicles as a safeguard for the transmission and engine. This fail-safe mechanism ensures their protection by alerting you and preventing additional harm in case an issue is detected with the engine.
When your vehicle enters limp mode, it might become incapable of shifting into higher gears, often becoming locked in second gear for most vehicles. Consequently, high-speed driving becomes unfeasible, potentially posing a challenge if this occurs while you’re on the highway.
Read More: Limp Mode Causes and Symptoms
Causes of a Bad Fuel Pressure Sensor
- Normal wear and tear
- Faulty wiring, short circuits, or loose connections
- Corrosion and contamination
- Excessive pressure variations within the fuel system
- Dirty or poor-quality fuel
- Physical impact on the fuel pressure sensor
- Excessive vehicle vibration
- Manufacturing fault
- Engine overheating
How To Test A Fuel Rail Pressure Sensor?
You can perform a DIY diagnosis for a faulty fuel rail pressure sensor using a few simple steps that require basic tools. These tasks are straightforward and can be easily followed. If you have access to your vehicle’s service manual, then you should follow the manual instructions. Follow the below-given steps to test your fuel rail pressure sensor.
- Turn off the engine and let it cool down properly.
- Connect a scan tool to the OBDII port. This will reveal the trouble codes responsible for triggering the check engine light. By examining the trouble codes, you might identify the issue and replace any malfunctioning components.
- Now, remove the fuel rail pressure sensor. In a few vehicle models, this might involve just a few connections, making removal straightforward. But your system could necessitate disconnecting a vacuum hose to access the sensor.
- Gently extract the fuel pressure sensor from the fuel rail.
- Test the electrical wiring and connectors connected to the sensor using a multimeter. The multimeter should be connected to the signal and ground wires of the sensor. Measure the signal wire’s voltage. If there is no voltage or a significantly different reading, it indicates an issue with the sensor or wire.
- Verify the integrity of the ground connection.
- If possible, check the fuel pressure within the fuel rails using a fuel pressure gauge. Compare the reading to the reading written in the owner’s manual.
Replacement Cost of the Fuel Pressure Sensor
Many factors (such as your living area, the type of vehicle, and the brand type) affect the replacement cost of the fuel rail pressure sensor. The average fuel rail pressure sensor replacement cost is from $190 to $350.
Plz, note that in this cost, the labor cost is from $135 to $245 while the cost of the parts is from $55 to $105.
| Labor Costs | $135 – $245 |
| Parts Costs | $55 – $105 |
| Total Average Costs | $190 – $350 |
FAQ Section
What is the function of the Fuel rail?
The main function of the fuel rail is to take fuel from the fuel tank and deliver it to the fuel injector, which injects fuel into the engine combustion chamber.
Where is the fuel rail pressure sensor located?
The fuel rail pressure sensor is usually installed near the center of the fuel rail and is connected to the powertrain control module (PCM). These sensors are most commonly used in some gasoline engines and many diesel engines.
What does a fuel rail pressure sensor do?
The fuel pressure sensor basically measures the fuel pressure inside the fuel lines. After measuring fuel pressure, it sends this data to the engine control unit, which uses the data to control the fuel pressure inside the fuel rails.
What are the signs of bad Fuel Pressure Sensor?
The following are the most common signs of a bad fuel pressure sensor:
- Poor fuel mileage
- Engine stalling
- Check Engine Light
- Poor acceleration
- Hard starting conditions
What happens if you unplug fuel rail pressure sensor?
In the event that the fuel rail pressure sensor is disconnected, the fuel pump will operate at a predetermined rate. This can potentially result in the engine operating with diminished power and throttle response. Such a situation could contribute to a decline in fuel efficiency and an increase in emissions.
Can a faulty fuel rail pressure sensor throw a code?
When the fuel rail pressure sensor malfunctions, disrupting the fuel-air mixture balance, it triggers an error code in the vehicle’s computer system. Using a compatible scanner, you can retrieve this code. The code might be a generic one, such as indicating a cylinder misfire, which doesn’t precisely pinpoint the issue until additional diagnostic steps are taken.
Can I drive with a bad fuel pressure sensor?
Yes, it is possible to drive with a bad fuel pressure sensor but it is not recommended. Driving with a faulty fuel rail pressure sensor may lead to poor engine performance, poor fuel economy, and complete failure of the engine.