I'm posting this tutorial because finding XC90 specific information on the web for this was pretty limited. This covers the removal and replacement of the Fuel Control Unit (FCU) also known as the Pump Electronic Module (PEM). From here on out I'll refer to it as the PEM.

First let me share what led to me replacing this on my XC90. I was having intermittent hesitation issues. It began as slight intermittent hesitation on the highway to the car stalling and eventually not starting leaving me stranded. See the following thread for more information:
https://volvoforums.com/forum/volvo-...y-ideas-70511/

Car:
2005 XC90 / 2.5T / FWD

Codes:
P0089 (fuel pressure regulator)
P2177 (system too lean off idle)
P0087 (fuel rail pressure too low)

Interventions:
1. Replaced the fuel pressure sensor (no change)
2. Replaced spark plugs (no change)
3. Replaced fuel filter (car ran perfectly for a few weeks, self clearing the CEL)
4. Ran some Seafoam cleaner through a tank of gas (car continued to run fine)
5. Cleaned MAF (no change)
6. Replaced fuel pump (no change)

The car would run fine after sitting for a few days making me think whatever I replaced fixed the issue only to have the issue resurface within a week or so. This finally lead to the one thing I hadn't looked at yet which was the PEM.



Removal and Replacement of the PEM

1. Disconnect the negative terminal of the battery before you begin.

2. Jack the passenger rear side of the car up and remove the passenger rear wheel.

3. Remove the two plastic nuts that hold the wheel well liner in place with a 10mm socket.

4. The PEM is located behind the front portion of the wheel well liner. You have to carefully peel it away from the plastic moulding. Once free I closed the back door on the liner to keep it out of my way while working.





5. The PEM sits in a bracket that's attached to the chassis. Get your fingers behind the bracket to work it free.



6. Remove the PEM from the bracket and unplug the electrical connection. If yours is corroded like mine was this will take patience and time. Just keep working the plug back and forth until it lets loose. In fact I ended up breaking the locking tab before getting it apart.

7. Check your plug connections to see if they're corroded. If it is (like mine was) take a little time to remove the corrosion with something abrasive making sure not to damage the plug. This will help ensure a good connection.









8. Plug in new PEM, replace in old bracket and reattach to the chassis.
NOTE: There is a way to relocate the PEM to the interior of the car. I decided against this. The first one lasted 7 years and 200K miles so I feel confident the new one will last as long as I need it to. With that said the location of the PEM in these cars is pretty dumb. As an alternative Xemodex offers a waterproof version.

9. Replace the wheel liner and secure with two plastic nuts.

10. Replace wheel and reconnect the battery.

Hope this helps others. Good luck!

 

Good write up. One other benefit of relocating it is the harness going to it is replaced. If the connector going to the new one has corrosion in it, it can fail quicker.

 

Great point. I forgot to mention that I removed the corrosion from my plug connectors before plugging in the new PEM. I updated the write up with a step reminding people to double check that.

Or as you mentioned, relocation requires a new harness which also solves the issue.

 

Hi to all,
i have the same dtc P0089 and i have changed fuel pump 2 times, every time it helps for about one year. No one in our volvo dealer know what was the problem, then i find this great post!!! I run to the garage to check and what!!! Pem was absolutley flooded by water i open and i saw a lot of rust! Now i'am waiting for new PEM Price is about 140$ becuase i find it in ford dealer when you look at pem there is ford part number

 

I had no idea there was a Ford cross reference number. Please post the part number you ended up getting so others can save some $$$. Volvo PEM units at the dealer or online are $250 - $300.

The one I got cost $150 and was a used unit from a Volvo model that had the PEM located in the trunk. I'm pretty confident it will last as long as I need it to. And if not I'll just buy another used one!

Thanks!

 

Hi here you are

[IMG] Uploaded with ImageShack.us[/IMG]

can anyone share part numbers needed to relocate PEM module? In Poland nobody knows that it can be relocated so nobody can tell needed part numbers!!

Cheers

 

I can give you more Here you have cars that are equipped with this part number

 

2006 XC90 2.5 AWD
Alright so i replaced the fuel pump after it died on the side of road, then ended up with similar intermitant hesistiation. Pulled the codes which lead me to believe my PEM was the likely problem after encountering this thread.
My Local Volvo dealership quote $541 for the parts plus labour to relocate and install. Naturally, I ordered a ruggized PEM from Xemodex $299 and armed myself with the tutorial. However once I got liner pealed back from the passenger rear I found no PEM to replace. If it was relocated by volvo at previous service where would I find it now?
Thanks
Mike

 

second place is under rear passanger seat under all carpets

 

+1 on location.

It seems strange it would fail again if it was relocated. The elements are what cause them to fail in the first place so you would think relocation would fix that.

Have you already checked your fuel pressure sensor? Those are many times the culprit with hesitation issues in XC90s...just a thought.

If you know where the vehicle was serviced you could always call to see if they have the records of what was done to the car. Sometimes works, sometimes not.

The below link is a fuel pump tutorial but it also tells you how to get the back seats out. Now if you did the pump replacement yourself you already know this, but just in case. Good luck, hope you get it figured out!

https://volvoforums.com/forum/volvo-...utorial-70880/

 

Thanks Guys,
New fuel pressure sensor installed and my P0089 & P0087 are gone. I was quite happy after reading that this task was a chore on V8s I was able to complete the task in 10 mins.
Still getting a bit of hesitation and now a P0100. I think I'm hunting vacuum leaks next.
Cheers
Mike

 

GOOD Now pls post part numbers for other members!

P

 

I have a few questions for the guru:

1. Can you simply clean the corrosion of the Fuel Control Unit (FCU)?
What is the mode of failure: corrosion at the pins or internal failure?
Why replace it when you can clean it?

2. Any preventive maintenance one can perform: such as removing it and clean the contacts/grease it?

 

Definitely not the guru...just had to go down the road myself and hoping to help others along the way.

1. Cleaning is probably a good first step to see if it helps. Getting to the PEM/FCU isn't a hard job so cleaning might be a good first step. Regarding why failure happens, I'm not sure. My unit definitely made noise when I shook it leading me to believe the inside was a mess. The answer might be a little of both - connector and internal failure. However as you noted why not try cleaning it first? I replaced mine because I was tired of chasing my tail after a few months and was ready to be done.

2. Cleaning the contacts and applying dielectric grease seems like a good theory. You could tape or shrink wrap the connector also in an attempt to keep the elements out.

You brought up some good points, and it makes sense to go from easiest/cheapest and work your way up.

 

Thanks,

I don't have any engine problem yet. Car runs fine.
My post above is strictly about "preventive maintenance".

 

I found mine in the trunk yesterday on my 2007 s60 but its totally brand new looking. I also have an intermitten p0089 code pop up a few times over the last 6 months and now a new p0027 pop up stating i need a new camshaft position sensor. So the fact that mine is pretty brand new (I had no clue what this was until this thread so thanks) it most likely is my sensors acting up. I don't mind paying to fix but don't want to spend tons of money if its actually something else. Like software problems etc.... I'm also tired of being hosed by people, because I'm a woman.

How much should a fuel pressure sensor cost? I've seen it range from 80 (sale price online) all the way up to 289 dollars from local. I'm frustrated because my mech said he didn't even look at the sensors yet, because he didn't want to remove them or risk breaking until we had the new ones in, yet I open my hood yesterday and flipping fuel sensor is completely unplugged.... The clip wasn't broken at all as I reconnected it immediately. You can believe I called and told them what I thought about that. Does anyone have tutorials on how to change these two sensors? Is it easy to do? I'm extremely frustrated. I live in a part of Canada where there is no volvo service repair specialists.

 

P0027 does not mean you need a cam sensor. And I would not trust an $89 fuel pressure sensor

 

I have 2006 xc90 2.5 5cyl turbo.
I have been struggling with a P0089 for abt a year now. Orig p0089 reared its ugly head with a 0027 code as well. I have have replaced exhaust cam sensor, fuel pressure sensor at the end of fuel rail on manifold, fuel filter, gas cap (after market). 0027 code is gone. P0089 goes away from time to time, but comes back within 10-20 miles.; basically always there.

I have absolutely no noticeable performance problems with car (if I can't fix p0089 soon I may develop personal performance problems ) I was about to try another fuel filter or gas cap before trying new fuel pump.
I want to fix this myself, plus I read posts where dealers don't get it right as well.
This PEM seems promising. Fuel pump and PEM are abt same $. It just seems to me the pump isn't the problem if I can "race" the car or drive normally with no performance/hesitation problems.
What to do.

 

I still get a P0089 code from time to time. It is frustrating. I've replaced the whole fuel delivery system except for injectors. As long as the car seems to perform well I'm probably not going to do much more.

So...I feel your pain.

 

Mikepor,
We both have same car. did you find PEM under seats? you said you changed "fuel pressure sensor" and codes are gone. did you mean PEM or fuel pressure sensor (sensor at the end of fuel rail at manifold). I have hope that the PEM is my final fix for this p0089 problem (plz refer to my post here #18). So, what part did you mean and did it work