ECM-2900 and P0089 - 2005 XC70

apaquette95 · Post by **apaquette95** » 26 Mar 2023, 14:23

Hello everyone, I have an issue with my 2005 XC70 and I'm running out of ideas on how to diagnose it.

The problem is that my car randomly looses power when going at higher speeds (90-120 km/h). Otherwise, the car starts without any issues and runs fine in the city.
The codes I get are P0089 and ECM-2900, both of which seem to indicate a problem in the fuel delivery system.

However, I don't want to blindly change parts so I ran some tests and here's what I gathered:

Fuel pressure in the first seconds after start is around 50 psi (measured with pressure gauge hooked to schrader valve on the rail) / 70 psi (measured with OBDII tool)

Fuel pressure at idle is around 40 psi (measured with pressure gauge hooked to schrader valve on the rail) / 58 psi (measured with OBDII tool)

Fuel pressure with pump at 100% (connected directly on the car battery) is around 60 psi (measured with pressure gauge hooked to schrader valve) / not measured with OBDII tool but assuming the delta in pressure is the same as start and idle, it should be around 80 psi

Pressure drops around 8 psi every 10 min, from what I can gather, this is acceptable

Fuel pump duty cycle is measured at below 1% by my OBDII tool which I find weird (should be around 35% at idle!)

For some more context, I changed the fuel filter a year ago so I don't believe it is the culprit.
I also changed the ignition coils almost 3 years ago so they should still be fine.
Finally, the PEM was changed 7 years ago and mounted in the trunk so I believe it should also be ok (no signs of rust/gunk/water anywhere on the connector or near the PEM).

The only two parts that were not changed and that, from my understanding, can be linked to my issue, are the fuel pump and the fuel pressure sensor.

For the fuel pressure sensor, it seems to read the pressure at the rail reliably and I don't think this could be the problem (see picture below).
For the fuel pump, since it can deliver up to 80 psi consistently, so I don't believe it's the issue either.

: Fuel pressure at start (70 psi for a few seconds then down to 58 psi); PXL_20230326_171250253.jpg (455.89 KiB) Viewed 1741 times

Only thing bugging me is the fact that the pump duty cycle measured by my OBDII scanner is way out there at less than 1%. This doesn't make any sense but I'm not sure what that means and where I should be looking to diagnose it. I haven't seen anything on this issue anywhere on the internet so I'm a bit at a loss.

Any help would be appreciated!

Post by **xHeart** » 26 Mar 2023, 16:17

apaquette95 wrote: ↑26 Mar 2023, 14:23 The problem is that my car randomly looses power when going at higher speeds (90-120 km/h). Otherwise, the car starts without any issues and runs fine in the city.
The codes I get are P0089 and ECM-2900, both of which seem to indicate a problem in the fuel delivery system.

It seems the issue is after the metered air. Check the air intake hoses for cracks, slits, tears, clamps. All hoses connect to turbo, big and small; AND the intercooler hose to ETM.

apaquette95 · Post by **apaquette95** » 26 Mar 2023, 18:37

Alright, I will take a look at that.

Could it also be the MAF sensor or the ETM itself failing?
From this thread, it seems like the MAF sensor failure might be what corresponds the most to my issues (idle running fine but stutters at highway speeds) : viewtopic.php?t=17252

Post by **xHeart** » 27 Mar 2023, 07:43

apaquette95 wrote: ↑26 Mar 2023, 18:37 Alright, I will take a look at that.

Could it also be the MAF sensor or the ETM itself failing?
From this thread, it seems like the MAF sensor failure might be what corresponds the most to my issues (idle running fine but stutters at highway speeds) : viewtopic.php?t=17252

It is early... the air flow data from MAF and ETM are erratic when engine is warm/hot, two ends of air flow. The coupler at the turbo/ charged-air-hose is a good starting point, then continue to the either ends.

Be safe, solve it before you drive again.

apaquette95 · Post by **apaquette95** » 27 Mar 2023, 19:23

xHeart wrote: ↑27 Mar 2023, 07:43
apaquette95 wrote: ↑26 Mar 2023, 18:37 Alright, I will take a look at that.

Could it also be the MAF sensor or the ETM itself failing?
From this thread, it seems like the MAF sensor failure might be what corresponds the most to my issues (idle running fine but stutters at highway speeds) : viewtopic.php?t=17252
It is early... the air flow data from MAF and ETM are erratic when engine is warm/hot, two ends of air flow. The coupler at the turbo/ charged-air-hose is a good starting point, then continue to the either ends.

Be safe, solve it before you drive again.

All right, here's some news from some early assessment of the air hoses.

First, the fresh air hose wasn't fully seated in the front of the car (the end with a rectangular shape).
Second, the air filter was full of debris (see picture below).

I doubt those two problems were the issue but I could be wrong.
That's the only thing I found for now. I'll keep looking I guess!

: PXL_20230328_002431873.jpg (435.71 KiB) Viewed 1685 times

Vova585 · Post by **Vova585** » 27 Mar 2023, 21:43

Sorry to hear about your problems. Intermittent issues are the worst to deal with.
If we to hypothesize that issue is still on fuel delivery side I would opt to check the fuel pump screen and electrical connections to the pump. Some tips for that- make sure your tank is at around 20% capacity. Before attempting to open the tank get yourself a tool to unscrew the cap and replacement rubber tank gasket. I would first vaccuum around the fuel pump access and then use compressed air to blow the remaining dirt out. This way you would be able to inspect the screen on pump and check electrical connectors on top of the tank for any corrosion.
I would then try to erase codes and drive until money light is back. I would try to get freeze frame data and post here.
Good luck

Vova585 · Post by **Vova585** » 30 Mar 2023, 20:19

Hope helps.

Seed · Post by **Seed** » 19 May 2023, 08:50

Curious what the problem was. I’m having same exact symptoms. Replaced filthy air filter, reconnected that same rectangular hose in front and put in new MAF. Not fixed. Did you solve it?

apaquette95 · Post by **apaquette95** » 20 May 2023, 07:10

Seed wrote: ↑19 May 2023, 08:50 Curious what the problem was. I’m having same exact symptoms. Replaced filthy air filter, reconnected that same rectangular hose in front and put in new MAF. Not fixed. Did you solve it?

I'm not sure yet, after I replaced the MAF sensor, the issue went away for a week but it came back in full force while on the highway.

I didn't find any air leak, so I didn't investigate more in the air department.

However, I changed all the spark plugs, ignition coils and fuel injectors as they were real old anyway at this point and that fixed some codes I had (ECM-35XB), but not all of them. I also changed the fuel pressure sensor for good measure. I didn't really try the car since so I can't say if the issue is gone.

However, I still have ECM-2900 and P0089. I also got new codes pointing in the direction of the ECM (1F00 and ECM-930B). I decided to check if corrosion was present at the connection of the ECM, but everything looks fine.

I'm still not confident the issue is fixed since I have the same codes as before. I'm leaning towards an electrical issue (my CEM was changed by xeMODex soon before the problems started, so my next guess is that) but any tips are still appreciated!

Seed, if you solve your issue, I'm interested to know what fixed it!

apaquette95 · Post by **apaquette95** » 30 May 2023, 16:19

Alright, quick update.

It seems that changing the spark plugs/ignition coils fixed my misfire issue.

However, since I still have the ECM-2900 code, I decided to test my fuel pump using Vida's quick test (as shown in this video : https://www.youtube.com/watch?v=z9WMP2uiuic).

Here's the resulting curve :

: IMG_20230526_192849_948.jpg (526.86 KiB) Viewed 1472 times

As seen on this curve, the maximum pressure the fuel pump can achieve is 550 kPa, even when Vida asks for 700 kPa (the maximum value it should reach is 650 kPa according to Vida).
Should I worry about this or can I wait a few years before changing the fuel pump?

Also, as said in my first post, the fuel pump duty cycle is always at less than 1%, which makes no sense and I'm not sure what is causing it!

Any help appreciated