5 Symptoms of a Bad Fuel Rail Pressure Sensor (and Replacement Cost)

A fuel rail pressure sensor (commonly known as a fuel pressure sensor) is used in many diesel and some gasoline engines. This sensor is usually located near the middle of the fuel rail and is linked to the engine control unit (ECU), which is the central computer of a vehicle. It shouldn’t be confused with the fuel tank pressure sensor which is located inside or on top of the fuel tank.

So what happens when the fuel rail pressure sensor goes bad and how will you know? Keep reading to see what a fuel pressure sensor does and common symptoms to look for with a faulty fuel pressure sensor.

What Does a Fuel Pressure Sensor Do?

what is a fuel pressure sensor?

The purpose of this sensor is to keep track of the fuel pressure within the fuel rail. As the sensor detects this information, the data gets transmitted to the engine control unit. From there, the computer will analyze the data and make the necessary changes to the timing of the fuel injections and the quantity of the fuel being injected.  This allows for optimal engine performance for the current driving conditions.

The engine control unit will specify the correct amount of fuel that the engine needs. If more fuel than necessary is injected into the combustion chamber, your fuel economy worsens. Not only that, but the lifespan of emissions related parts decreases and excess carbon emissions are expelled into the atmosphere.

Since most vehicles on the road today are made to be as environmentally friendly as possible, this makes the fuel rail pressure sensor a vital component that must remain functional at all times.

Top 5 Symptoms of a Bad Fuel Pressure Sensor

fuel pressure sensor replacement cost

If there is a problem with the fuel rail pressure sensor, the engine control unit won’t be able to do its job properly. Here the 5 most common signs of a bad fuel pressure sensor.

#1 – Check Engine Light

When your fuel rail pressure sensor goes bad, the “Check Engine” warning light may illuminate on your dashboard. This light activates whenever the engine control unit detects an issue within the vehicle that affects the engine in some way.

This doesn’t always mean the engine itself is bad, but rather something else in the vehicle which is not allowing it to do its job properly. You probably won’t know it is the fuel rail pressure sensor at first but using a diagnostic scan tool can often confirm the issue. P0190, P0191, P0192, P0193, and P0194 are the most common DTC codes indicating an issue with the fuel rail sensor.

#2 – Difficulty Starting Engine

If you have a bad fuel rail pressure sensor, the ECU won’t send the right amount of fuel to the engine. This will make it difficult to start your vehicle. When this problem first occurs, it will probably take a couple attempts cranking the engine before it starts. But as the problem gets progressively worse, it will take more and more attempts to start. Eventually, the engine won’t start at all.

#3 – Weak Acceleration

poor acceleration

When you step on the gas pedal and the vehicle does not accelerate like it’s supposed to, then you could have a bad fuel pressure sensor. The engine control unit is not able to transmit the signal properly to the fuel system because it gets inaccurate information from the sensor. That means it won’t know how to accommodate the fuel demands being placed on the engine.

#4 – Stalling

Engine stalling might occur as the fuel rail pressure sensor goes from bad to worse. You will be driving and then suddenly, your engine will stall. It may also stall while idling. This will make driving extremely difficult (and dangerous) and it should motivate you to do something about it. Take your vehicle to the nearest auto shop right away and get your sensor replaced if it turns out to be the cause.

#5 – Bad Fuel Mileage

bad fuel economy

When your fuel pressure sensor doesn’t work like it should, you’ll notice a considerable reduction in fuel economy and mileage. Either your engine control unit will send too much fuel or not enough fuel through the fuel rail and into the combustion chamber. You will quickly notice more trips to the gas station and more money out of your pocket.

Those will larger vehicles will usually notice a reduction in fuel economy the most. For instance, the fuel economy of a Duramax engine will be affected more noticeably than something like a Honda Civic.

Fuel Sensor Replacement Cost

The cost to replace a fuel rail pressure sensor can vary quite a bit depending on make and model of your vehicle. On average, expect to pay between $200 and $340 total for a fuel rail pressure sensor replacement. Parts alone will set you back about $60 to $100 and the labor cost to replace the sensor will cost between $140 and $240.

Of course, you’re usually going to pay more when you have a dealership perform the work compared to an independent mechanic. Unless you have a good amount of auto repair experience, you should not attempt replacement yourself in most cases.

 

Comments

  1. I have replaced a new rail pressure sensor but the car still do not perform. What could be the challenges or next step

  2. Hi.I have an open vivaro 1,9 cdti the car does start properly when its cold it does pour too much fuel on the engine smoking all the way black smoke and it wouldn’t burn that diesel anymore as its too much then it will just stops for it to start again I must wait for at least 2 hours to start as diesel will be sinked.so its a problem to me I don’t know what could be the problem fuel rail pressure sensor or injectors.

  3. Hi, i have a 2009 2.0 tdci (140) smax, and the motor crankshaft but doesn’t start hot, i’ve to wait until it comes to 60° to start. I’ve also changed the crank and cam sensor, the ect sensor, and now i see on cold start the rail pressure is 430/450 kPa. On hot the rail pressure is 210 kPa. What can i do? Thanks.

  4. thanks for your help always. my car a nissan caravan common rail ddti is not performing well even though I have replaced a fuel pressure sensor

  5. I’m having weak acceleration problems with my 1998 Ford Taurus on restarts and going up hills I read about the fuel rail du think that my problem sounds like that problem

      • Its possibly the EGR,which is a cheap and simple job to do.like wise the fuel pressure sensor cheap to buy and fit on most cars.

  6. hi all

    I have an audi S5 that’s really doing my head in, I have had the car plugged in and the code showed high pressure sensor was faulty, I have had this changed but no difference, car struggles to start and does not like acceleration at all it just jerks the garage have told me they don’t really know what else to try to fix it, anyone got any ideas as iam going out of my mind

  7. Persistent starting problem after replacing fuel pressure sensor may be due to scv not sending signal(current) to the vehicle ECU. This is required for the adjustment of fuel sent to the injectors. Reset error code twice and try starting the vehicle. Good luck

  8. Any shortcuts for replacing a fuel sensor on a 2011/12 dodge 6.9 cummins
    I cant physically get to it.
    Tool recommendation?

  9. What diagnostic tool can work on most diesel engine car in the philippines? Any recomendation? I bought a 2nd hand hyundai starex and abs light is on all the time. And it doesn’t accelarate properly as it should. I want to find out myself what is wrong. I already cleaned the injectors and egr. I dont want to go to mechanic. For they will surely rip me off

      • I bought a 2019 caravan 2 months ago with 14 miles on it. I took it in a few weeks ago because engine light came on. The service department ordered a part and said it was fuel censor. Two week later van kept cutting off and stalling at every red light. They think the part the put I was defective. Dodge has had the car for 2 weeks and still in diagnostic stage. I am a Uber driver so No income for two weeks. What are my options? I am tempted to buy an $10,000 car for back up because I need to work. Dodge gave me a rental but I can not Uber in it. Not sure I want the van back if it’s is going to have problems this early. The first payment is due in 2 weeks. Only 7000 miles on van. 😥

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