Re-upping previous post- XC90 No start

powersct · Post by **powersct** » 26 Feb 2011, 15:46

Thought I had this figured out- but still no start...

Trying to help out a friend here. 2005 XC90 v-8. No start and threw 2 codes- P0089 and P0191. So far I diagnosed the fuel pump not running and replaced it- now pump running but still no start, so started looking into the pressure sensor and replaced that as well- no help. Out of ideas and need a new one!

Thanks in advance.

Post by **jimmy57** » 26 Feb 2011, 20:14

I typed this before and somehow failed to get it to post:
The fuel pressure test port is just below the FPS you changed. It is the regular tire valve sized schrader valve fitting.
Fuel pressure should be just below 60 psi, 380 kPa. You should be able to get fuel pressure reading by cycling ignition on several times or during cranking.
The fuel pump module (AKA pump electronic module) is in front of rt rear wheel under the fender liner. Connector problems at the FPM have been cropping up.
89 would be for low pressure and 91 is for problems in circuit for fuel pump controller.

powersct · Post by **powersct** » 27 Feb 2011, 06:18

Good stuff to add to the list- thanks. Back to the basics this morning and we'll see where we go...thanks again.

powersct · Post by **powersct** » 27 Feb 2011, 13:46

Jimmy, this is just weird. There is no fuel pressure. As I mentioned, I just installed a replacement pump. Prior to installing it, I plugged it in and ran it for 2 seconds max to test it and it ran- then installed.

Today in my narrowing steps, I started with the schrader at the filter- nothing. Put the stethoscope on the pump today and it's not running.

Before I pull the fender liner to get to the module, are there ohm meter tests I can run on the module? You mentioned the connectors- might it be a matter of cleaning- re-seating or should I start looking for a module? Thanks in advance...

Post by **jimmy57** » 27 Feb 2011, 15:48

The module is a transistor power stage commanded by the ECM. I would have to download and look at the wiring diagram manual to give accurate instructions. There have been a number of pump failures and often they blow the fuse. The fuse is on CEM up front under dash on left. The power supply to FPM is through an integrated relay built into CEM. but the current control is via the FPM. ECM reads the FPS to determine signalling to FPM. The connector can corrode on the FPM. FPM's were relocated due to connector problems. My approach would be wiring diagram download (from "repair database" tab above), then fuse check, then power supply check when someone turns on the key or attempts to crank, then signal check from ECM. The signal wire from ECM will be on the diagram. Signal will change while starter operated vs key on (except for the 1.5 seconds when key is first on) and I think it will go down in voltage as I believe it will be a ground pulse. Important part is voltage change when pump should be running, either decrease or increase from initial voltage. Ground pulses on a power supply base signal lowers lowers voltage, power pulse on a ground base raises voltage. One of these should occur on wire traced from ECM to FPM. FPM may be called PEM on wiring diagram. I think the name change to Ford acronym was after 05.

powersct · Post by **powersct** » 27 Feb 2011, 16:23

Excellent- got it. Thanks. I'll post the outcome.

powersct · Post by **powersct** » 28 Feb 2011, 14:22

This thing is just killing me. Pulled the module- heavy corrosion and covered with crud. Cleaned it all up and it appears to be working as the pump is running on key and crank. After 'priming' for awhile I still have no pressure at either schrader. Further ideas welcome...

Post by **jimmy57** » 28 Feb 2011, 14:34

Not to be oversimple but you do know for sure it has fuel in it?
Bang on the tank and make sure the fuel is not all on the left. There are two pumps, the one that sends it to the injection and the one that runs full speed full time to push fuel over to the left side through a jet/siphon orifice deal and pick up left side fuel and spit it into the fuel pump cup on right where both pumps are located. You could be hearing the pick up pump and not the main pump also. Did you replace the pump assembly cup with both pumps or????

powersct · Post by **powersct** » 28 Feb 2011, 14:56

Came in 3/4 full- drained off around half that to ease spillage. Gauge currently reads over 1/4. The replacement pump was the full assembly with cup. The 'ejector' (plastic piece they suggest to attach the snake wire) as they call it is fully submerged in fuel on the *left (my other right-lol)- wouldn't that be enough?

Sorry, read it fast. Are you also suggesting that the 'injector' pump isn't running and the pickup pump might be?

Further clarification- the pick up pump runs "full time"? Not hearing that- it's running on key for maybe 5 secs then runs on crank...

** Just for giggles, I plugged in the pump I took out and it runs as well (didn't fully re-install it, just plugged it in). So it appears that the pump itself wasn't the problem. The replacement was used (documented at 49k) and I may swap them again based on what you have said above- but I will await further wisdom before doing it...

powersct · Post by **powersct** » 01 Mar 2011, 15:43

Thought I would update the thread although the final determination has yet to be seen.

The owner of the car arranged a consult with a Volvo dealer mechanic on the phone. After explaining the steps I have taken and everything I have done, he concurred that the problem is a strange one and that my logic has been correct. There was some progress after cleaning up the control module, so, In conjunction with the Volvo guy's estimation I gave the owner a choice- hook it to the dealer or buy the module- no guarantees of course...the module is on the way and I will post the final outcome.

I personally have had at least one Volvo in the fleet for as long as I can remember (No XC90's) and have to say while it's a heck of a nice vehicle, after working on it and reading the horror stories around the web (mostly electrical) I think a BMW X5 is a superior choice to the XC90.