Description of fault code P0117,
OBD2 Error Codes

P008B Fuel System Low Pressure - Pressure Too High

P008B Fuel System Low Pressure - Pressure Too High

OBD-II DTC Datasheet

Low pressure fuel system pressure too high

What does this mean?

This Generic Powertrain Diagnostic Trouble Code (DTC) typically applies to all OBD-II vehicles. This may include but is not limited to Hyundai, Ford, Mazda, Dodge, etc.

Low pressure fuel systems are commonly used in diesel systems. The fact that the fuel pump does the hard work is providing diesel engines with the high pressure of fuel they need to properly atomize fuel.

However, the fuel pump still needs to be supplied with fuel. This is where low pressure fuel pumps / systems come into play. It is extremely important that the ECM (Engine Control Module) closely monitor these conditions. The reason is that any entrained air caused by a shortage of the injection pump / nozzle under load can and will cause serious problems. Forced power limitation is usually a kind of mode that a vehicle enters into when it needs to control certain values ​​to prevent further engine damage by the operator. Fuel also has to go through numerous filters, pumps, injectors, lines, connections, etc. to eventually get into the engine, so as you can imagine, there are many possibilities here. Even small fuel leaks will usually cause an odor strong enough to be noticed, so keep that in mind.

By monitoring numerous other systems and sensors, the ECM has detected a low fuel pressure and / or insufficient flow condition. Be aware of local fuel conditions. Repeated refueling with dirty fuel can contaminate not only the fuel tank, but the fuel pump and everything else, to be honest.

P008B Fuel System Pressure Low - The code sets when the ECM detects high pressure in the low pressure fuel system.

What is the severity of this DTC?

High fuel pressure can and will cause problems in the future when it comes to diesel engines. I would say the severity will be set to moderate-high because if you plan on driving your car on a daily basis and it is diesel, you will need to make sure that your fuel system is functioning properly.

What are some of the symptoms of the code?

Symptoms of the P008B diagnostic code may include:

  • Low power
  • Limited exit
  • Abnormal throttle response
  • Reduced or increased fuel economy
  • Increased emissions
  • slow
  • Engine noise
  • Hard start
  • Fumes from the engine when starting

What are some of the common causes for the code?

Reasons for this code may include:

  • Dirty fuel
  • Fuel line or filter problem
  • Unstable fuel
  • Fuel injector defective
  • Weak low pressure fuel pump
  • Layered fuels (e.g. old, thick, contaminated)

What are some steps to troubleshoot the P008B?

Basic step # 1

Make sure there are leaks and repair them immediately. This can and will cause lower than desired fuel pressure in any closed system, so make sure the system is properly sealed and not actively leaking anywhere. Rusty lines, fuel filter gaskets, worn o-rings, etc. will cause fuel leaks.

Basic tip # 2

Check the low pressure fuel filter. They can be located on the rail or next to the fuel tank. This should be pretty obvious if the fuel filter was recently replaced or if it looks like it has never changed (or hasn't changed for a while). Replace accordingly. Keep in mind that air ingress in a diesel fuel system can be a tricky issue to troubleshoot, so make sure you follow proper air bleeding and filter replacement procedures. See Specifications and Procedures in the Service Manual.

Basic step # 3

If possible, locate your fuel injector. They are usually fairly easy to locate, but sometimes plastic covers and other brackets can interfere with a proper visual inspection. Make sure there is no fuel leaking through the fittings or connectors. Also, leaks are common around the injector itself (O-ring). Visually inspect for any signs of physical damage or, for that matter, anything that could cause a decrease in fuel economy (such as a kinked line on the injector). Particles in the fuel are a real possibility, given such small holes. Ensure proper maintenance of the fuel system (such as fuel filters, EVAP, etc.)

Related DTC discussions

  • There are currently no related topics in our forums. Post a new topic on the forum now.

Need more help with a P008B code?

If you still need help with DTC P008B, post a question in the comments below this article.

NOTE. This information is provided for informational purposes only. It is not intended to be used as a repair recommendation and we are not responsible for any action you take on any vehicle. All information on this site is protected by copyright.

3 comment

  • Razvan

    Hello!
    I have this p008b error code on my 2015 peugeot 508 2.0 bluehdi 180 hp.
    I have this error only in the morning at first start and it is appearing and dissapear.
    It is doing this for 5-10 minutes and when I push the brake pedal.
    After that no error code.
    Can you please help me?

  • I guess p008b

    Hello, I have a problem with error p008b on a Ford mondeo MK5 2,0tdci 110kw, out of nowhere my car started jerking while driving, so I pulled over to the side of the road and turned it off, when I went to start it again, the car was revving and revving and didn't want to start. Could you give me some advice? Thank you in advance

  • DEATH

    Error P008B - low fuel pressure system - pressure too high. Typical symptom: the error is thrown after starting a cold engine, after warming up the error disappears (of course it remains saved in the controller's memory). The problem is not a dirty (clogged) fuel filter. If the filter were clogged, the pressure would be too low. The problem is the seals (o-rings) sealing the fuel line between the filter and the high-pressure pump. Each of the ends of this line has two of the above-mentioned o-rings inside. Over time, these o-rings harden, crumble and crack. There does not even have to be a fuel leak because the second o-ring can still seal. A piece of such a chipped o-ring gets into the high-pressure pump together with the fuel and blocks the overflow channel in the fuel dose (output) valve seat on the pump. For this reason, on a cold engine, when the fuel is cold and thick, it drains worse through a clogged channel (in real values ​​it should be about 5 bars, but it can be 7-8 and starts to scream on the dashboard). When warm, the problem supposedly disappears! You have to remove the valve (the one with two screws and a two-pin plug). Access may not be ideal, but you can handle it. After removing the valve seat in one of the side holes in the high-pressure pump, you will find the cause of the error, i.e. a piece of hardened O-ring. Of course, the pressure sensor on the supply line between the filter and the high-pressure pump may also be broken, but before you buy such a sensor together with the line for a few hundred zlotys, start by dismantling this valve!! I have practiced this more than once and in 5 cars with this error, each had a clogged drain. Of course, I don't have to remind you to replace the O-rings on this valve and on the supply line during such a repair (you can buy them, there are stores where you can easily choose them). If such an error occurs after replacing the fuel filter, then the O-ring has definitely failed (they break during removal/assembly). And one more thing, I'm not sure if the same engine as in Peugeot or Citroen is in Ford, but the mechanism of this error is probably similar

Add a comment