2005 XC90, No fuel pressure

volvooh · Post by **volvooh** » 05 Aug 2019, 06:32

After arriving back home last night for a quick drive in the XC90, I went out to move it in the driveway and it would not start. Felt initially like it was get fuel but could not remain started.

Later, I checked pressure at the rail, and found it to be zero. I did not have access to my code reader. I have not encountered any diminished performance such as hesitation leading up to this event.

I have owned the car for a month, has 173,xxx mi and has been running quite well to this point.

I am going to start with the relay, and try to jump it first. I feel like the sudden onset points to relay, fuel module or fuel pump. I just don't think a fuel filter would be the culprit here.

Any thoughts are appreciated!

volvooh · Post by **volvooh** » 05 Aug 2019, 11:28

Is there a fuel pump relay on the '05 XC 90 or is it all handled by the PEM? I did not find a relay on the CEM under the d-side dash.

Post by **ggleavitt** » 05 Aug 2019, 12:02

Some info here- viewtopic.php?f=10&t=83957&start=10#p460721 , PEM manages the pump based on PWM signal from the ECM (demand controlled pump). CEM provides DC feed.

This is a 2005 so PEM is external unless someone has already moved it in the vehicle- https://forums.swedespeed.com/showthrea ... M-Location

Post by **Roger_850T** » 05 Aug 2019, 20:28

I agree. 0 fuel pressure measured at the rail points to a fuel pump issue, and the question is: is the pump not running, or is there an obstruction that prevents the fuel from flowing. ViDA will indicate what the CEM *thinks* the PEM is doing. See if you can find the fuel pump. If the pump is running, then that suggests obstruction (or some sort of reason why the pump isn't being very effective), or if the pump is not running, that's a different path to chase down. I do like measuring the pressure at the shraeder valve on the fuel rail - that's pretty definitive.

Roger

wanderdüne · Post by **wanderdüne** » 05 Aug 2019, 20:31

If it's a 2.5T, it also has a fuel pressure sensor at the end of the rail, for what it's worth.

volvooh · Post by **volvooh** » 06 Aug 2019, 07:30

Thank you all. I was able to get my code reader, and no codes. I chased down the PEM...for other 05'ers that experience this, it was located on the underside of the SUV right next to the fuel filter (This discovery was after removal of both rear wheels and fender skirts along with a long search through the trunk area). I really can't think of a worse possible location for an electronic device that does not even look like its sealed.
My son drives an 08 S60. His PEM was relocated to the trunk of his vehicle (and actually is using the Ford equivalent PEM) . A quick swap out of his PEM to mine and the fuel pump began to hum and the vehicle started right-up. Ordered a pull-off from Ebay for $49.99 from a donar vehicle with PEM located inside the car. I looked for the kit to move it inside and not finding it. Probably will replace it where it sits for now so that I can get it on the road and continue to look for kits for a future relocation.

Post by **ggleavitt** » 06 Aug 2019, 13:02

https://forums.swedespeed.com/showthrea ... he-harness , my '05 also has the PEM next to the fuel filter. I believe fuel tank size (68/72 vs 80) is the differentiator for location.

Harness is PN 8688667 as noted in the post above. Your original PEM lasted 15 years, you could in theory leave the "new" one where it is and do a bead of silicone around the snap-on top then some dialectric grease on the connector. Personally I would move the inside so it's done (harness or a good and sturdy splice) but you have some options for promoting longevity should you decide otherwise. My PEM is still outside the vehicle, can see photos in the second link in teh earlier post (it's in great shape).

Post by **cn90** » 16 Aug 2019, 07:49

My 2005 XC90 2.5T with 120K still has the original PEM. I have a used PEM from junk yard. I keep the used PEM in the trunk as spare, just in case.

Post by **oragex** » 17 Aug 2019, 06:35

The PEM is also sometimes located on the XC90 inside the right rear wheel well https://volvoforums.com/forum/volvo-xc9 ... ial-71534/

volvooh · Post by **volvooh** » 22 Aug 2019, 13:49

Just my luck that is where I started. Looked in one wheel well, then another, then all through the truck, then finally on the underside of the car, where it sat. I spent more time looking for it than actually fixing it.