Cannot find PEM/FCU in 2004 XC90 2.5t AWD

ondatrack · Post by **ondatrack** » 02 Apr 2020, 19:57

My 2004 2.5t AWD XC90 with 130k miles stalled and then would not start while driving home from work. There has never been any starting or hesitation issue prior. Gas tank is 3/4 full. I pulled a code P0089 with my Torque App. I didn’t have a pressure gage but there is no pressure at the fuel rail and just a few drops of gas drip out of the Schrader valve both while cranking and with key in the on position. I also checked the Schrader valve right before the fuel filter to make sure it wasn’t a clogged filter, it didn’t have any pressure either. My first thought was the fuel pump fuse, it was good. I swapped the relay under the dash with the fog light relay that was identical and no change so then I figured it was the fuel pump. In checking this forum and others I read it could also be the Fuel pressure sensor mounted on the fuel rail, which this one does not have or the PEM/FCU. I read the tutorial for a 2005 2.5t XC90 and started looking for the PEM/FCU. I pulled both rear fender liners with the wheels off and it wasn’t there. I pulled both rear rows of seats out along with the side panels and carpet. Still no sign of a PEM/FCU. I did pull the cover off the fuel pump and could not hear anything with the ignition switch on or while cranking. I unhooked the connector and put power directly to the pump and it turned on fine. There are three other smaller wires in the connector that go toward the rear but I could not trace them to anything without tearing the whole rear harness apart. I am at a loss now. I found a couple of threads on a forum that allude to some 2003 or 2004 models not having a PEM/FCU but the threads died with no confirmation that this is the case. Does anyone know for sure that this year and model does not have one? If it doesn’t other than the relay is there anything that would keep the pump from working? Thanks in advance.

wanderdüne · Post by **wanderdüne** » 02 Apr 2020, 22:07

Here: https://volvoforums.com/forum/volvo-xc9 ... ial-71534/

Post by **abscate** » 03 Apr 2020, 07:24

Behind liner in the XC90 models, right rear wheel IIRC

Post by **ggleavitt** » 03 Apr 2020, 07:40

https://forums.swedespeed.com/showthrea ... M-Location

Some alternate PNs as well in the thread IIRC.

Post by **jimmy57** » 03 Apr 2020, 10:00

If you have the 0089 code then you do have a pressure sensor on the end of fuel rail:

: FPS.jpg (9.06 KiB) Viewed 1853 times

: FPS.jpg (9.06 KiB) Viewed 1853 times

and you have the PEM and it should be in front of RR tire under liner if it has not been relocated inside under rear cargo floor.

ondatrack · Post by **ondatrack** » 03 Apr 2020, 17:45

Thank you for the responses. Unfortunately there is no pressure sensor on either end of the rails. There is no PEM in either of the rear fender/wheel wells, checked very thoroughly. I have pulled every piece of carpet, pad or interior trim out that is in back of the front seats and nothing. Unless it is under the floor pan on top of the gas tank I have looked everywhere.

Post by **jimmy57** » 03 Apr 2020, 18:50

That is strange. The low fuel pressure code is only possible when it has a way to monitor fuel pressure. That sensor shown is on the driver's end of the fuel rail acting as the end plug when it is there. If it has the code then it should have the sensor or it would have the codes for open or high signal for the fuel temp pressure sensor.

ondatrack · Post by **ondatrack** » 03 Apr 2020, 19:35

I thought it was strange also. There is a plug on the drivers side and a Schrader valve on the drivers side. In my reading I found other references and pictures that showed a 2004 2.5t without the fuel pressure sensor. Thanks.

Post by **abscate** » 04 Apr 2020, 04:50

The OEM could have been relocated inside or most anywhere, is there evidence of the old one under the liner?

Post by **RickHaleParker** » 04 Apr 2020, 05:34

Get a second option from a different code reader. I cannot find a P0089 to Volvo XC90 2.5 translation before MY 2005.