Hello,

I have a 2008 Volvo XC90 3.2 cyl, and I currently have the codes, P0087 and P0180.
I have already changed the fuel pressure sensor, the PEM, two new relays, and currently has a brand new Delphi fuel pump and brand new wiring harness to the pump.
The car still won't crank up, and if it does, the car will only run for 20-30 mins with a low fuel pressure.
I checked the wiring and noticed the skinny blue wire from the CEM and/or REM does not have any electricity, which I believe controls the high pressure pump. How do I get electricity to these wires?
Also, should I purchase a Volvo fuel pump?

 

Which blue wire are you referring to?

And what's your fuel pump duty cycle?

 

I haven't checked the duty cycle yet.
in terms of the blue wire, I just know it's the skinny one, and it comes from the CEM.
(From your response, it seems like I need to go more in depth on my data.)

The blue wire in bottom left corner of the harness.

 

There's 2 blue wires - one goes to the pump motor and looks like the other might go to the fuel level sender.

 

It is the blue wire that goes to the pump motor, particularly the high pressure motor inside the pump because I believe there is also a secondary pump too.

 

Here's the pin numbers on the pump - with a small and a larger blue wire - I would bet the larger blue wire is for the pump, to carry more current (than a signal for the gauge)

 

So number 1 is the smaller blue wire that is not getting electricity in my car.
Number 4 is the larger blue wire that is getting electricity.

Overall, what route should I take to get electricity back into the blue wire?.

 

54/36 is the 6 pin connector that plugs into the fuel pump. The small blue wire (at terminal #1) goes to one of the sending units (not the pump portion). Why would you want to inject power into that wire and risk melting your gauge or sending unit?

 

Well,
I assumed that wire was supposed to be getting fire, but I guess I was wrong.
With the low fuel pressure, I'm trying to figure out what's the next move.....
(Your terminal diagrams switched the numbers)

 

Those are wiring diagrams from Volvo - you can find them at Volvodiag.com under the EWD tab.

What's the fuel pump duty cycle?​​​​​
What's your fuel pressure measured with an external gauge?

The fault tracing that Volvo suggests for your code is - Measure the fuel pressure and compare it to what the pressure sensor is reporting.

 

Every time I use the fuel pressure gauge, it shows 0 kPa. I have used three different gauges.

 

What happens when you activate the fuel pump relay with your scan tool? Whats the pressure reading from the Fuel pressure sensor then? With 0 fuel pressure the engine will not run. Previously you stated the engine does run (for a while)

 

Lately, I haven't been able to get it to start at all.
Been trying to get the fuel pressure when turning the key to the initial state.
2008 XC 90 3.2cyl has no fuel pump relay

 

I was able to get a reading on the fuel pressure in the fuel system. It is 4 psi.

 

That is true - there is no external/replaceable relay. There may be one soldered in the engine control module or the CEM. Volvo's diagnostic software does have a way to activate the "fuel pump relay" manually. I trust that is to be able to check the fuel pump operation without the car running.

On the lower picture I'd imagine at least some of those 7 cubes soldered onto the CEM are relays.

Speaking of the CEM - water intrusion (into the CEM) is a problem on some Volvos - have you checked for that problem with your car? Anything else weird happening other than it has no fuel pressure even after replacing a bunch of parts?

 

Last week, I took out my CEM to check for water damage, but all was well since I'm in dry Arizona. I don't have the software to reset the fuel pump relay so I might hit up the junkyard to pull out a CEM.
Thank you, I'm also looking into getting the ECM reprogrammed.

 

To swap to see if that's the problem?

A used CEM will not work in your car. It will not talk to your other control units because it will not have your VIN programmed into it. A company such as xemodex can "code/program" a used Cem to match your VIN.

https://xemodex.com/us/available-ser...tronic-module/

 

Awesome!!

What contact/reference do you have for a company that repairs the ECM?
The two I have contacted are taking too long to get back to me.

 

Why do you think you have a problem with your ECM? Codes? Guessing? (Have only had to replace a couple of Volvo ECMs in 40 years)

https://xemodex.com/us/engine-contro...les-for-volvo/

 

I can't figure out why my fuel rail pressure went from too high, and now it is too low. Haven't gotten the car back on the road for 3-4 months. Turned the car off and it hasn't been right for a while. So I'm trying to get everything fixed. I have a brand new pump in the car now, but the fuel rail pressure is low. So I'm assuming it could be the ECM or CEM.