It doesn't work that way. The fuel pressure sensor is a resistive strain sensor that operates on the basis of a piezoresistive effect, the electrical resistance of a conductor varies depending on the longitudinal mechanical deformation of the sensing element inside the sensor. There are several failure modes, mechanical and/or electrical, that can cause the sensor to refuse to report a pressure higher than X psi regardless of the pressure of the fuel sent from the pump.

Just change the sensor like I told you. You already know it's cheap and an easy DIY. Repeatedly trying to somehow rationalize to yourself what the sensor, ECU or pump should be doing to report normal pressure is a waste of time. If that doesn't fix it you need to take the car to someone with a more advanced diagnostic computer to find out what is the underlying detailed error code, but right now changing the sensor is most logical action to take.

 

ok, thanks, i will replace the sensor and report back

 

If you really want to know what happening you would need to make an independent measurement of the fuel pressure at the rail.

The sensors are a know failure.

I would just replace the sensor as FLY_BD5 also advised.

Let us know if this solves your problem

Good luck

Paul

 

Before you start this little project, be sure you have a low-profile wrench (Torx T25) to fit into the tight space around the sensor. I haven't done this replacement yet myself (it's on my list), but reading about it indicates this is a pain point for some.

 

The Repair

Removing the T25 is the most difficult part. I used a key to get it loose and then a T25 screw driver to remove it the rest of the way.

I did eliminate the T25 s that it will be simple to change out next time (see the link for more information)

Pictures for my S80 are here (in case you didn't know the Engine in my LR2 and S80 are the same) https://www.matthewsvolvosite.com/fo...7687&start=110


Take care

Paul
.

 

Thanks for the link, but you didn't indicate the size of the replacement for the T25 bolt so one can be purchased in advance. Do you know the diameter, thread pitch, and length?

 

I think it's in the Freel2 link in the post on the Volvo site.

 

Replaced it, ordered Bosch 0261230238 from Amazon (Only 32 USD) . Interestingly Amazon states that it will not fit LR2 2008 but it will and is the correct part. Some sites suggest that the correct part is 0261230238 and others suggest it is 0261230110. Both will work as I checked the specs in detail.

I did not have the tool to remove the sensor easily as such ended up taking out the rail (which is not difficult at all and allowed me to clean the injectors).

The positive is that the car is very responsive to increased loads and I am overall happy that I changed the part as it runs like new however the P0087 code is still there. Recorded fuel rail pressure is same at near 50 psi rather than 54 psi.

I cleared the code with the scanner before it came back however I will also do a hard reset by disconnecting the battery. If the code returns, I will just ignore and keep an eye on fuel pressure and see if it deteriorates over time.

 

If the code is coming back that means the underlying problem is still there. I still think you should take it to someone who has the JLR SDD software to query further and give you more detailed fault information.

 

Sure, I will try to go to the dealership for a scan.