ECM 2900 - 2005 - V70R

[RuudKoster]

Hi Everybody!

I have an issue with the V70R. I've searched a lot about the issue, but can't find the exact symptoms I'm experiencing.

So I have an ECM 2900.
I have an Autel AP200 and read the fault code. If I erase it, it comes back in like 45 seconds.

The freeze frame of the fault registered 300 kPa of fuel pressure, I got several freeze frames from idle situation, slowly driving and full throttle, everytime it says fuel pressure around 300 kPa. However if I look at the live data it is always around 400 kPa and the car runs perfectly, even under full load. So I would say the 300 kPa is not the real value at the time when the fault is set.

I also measured the fuel pressure sensor and it gives me about 2 Volt. This corresponds with the table I found for the sensor. I replaced the FPS anyway, but no difference. I also checked and measured the ground of the sensor, looks good.
Since the Autel gives me 400 kPa which corresponds with the 2 Volts, I would assume everything from the sensor to the ECM shgould be good.

Then I noticed the fuel pump duty cycle which the Autel shows as 0,23% when idling, 0,11% if I let the throttle go and it goes slightly up to about 0,26% on WOT. I assume the Autel just shows it wrong and the values should be multiplied by a 100..
If this is correct the duty cycle is very low, but the fuel pressure is always around 400 kPa from idling to WOT under load.

I only read topics with a duty cycle that is to high and read a high duty cycle could be caused by a partly clogged fuel filter for instance. So to test if the duty cycle could get higher I slightly clamped of the fuel line. Idling there was no difference, but under load I saw that the duty cycle went up slighly faster, but still not passed 0,26%, even when the pressure dropped significantly.

I found a cheap second hand original PEM and mounted it. Unfortunately exactly the same problem..

Does anybody have an idea what could be wrong or has good advise on what to measure or check next?
I don't have VIDA and DICE, but I do have a decent multimeter


Some sidenotes. I have done some repairs and service to the car. I replaced the o-rings of the fuel pump and level sensor, but I drove 1500 km before this fault started to occur.. Could I have done something wrong with this that could cause this issue?

Thanks in advance!

[jonesg]

I like this video,



part 2,

[RuudKoster]

Thanks!
Very nice video, makes me understand the system a bit better!
Thing is though I have a low duty cycle (if I read the Autel correct) and the duty cycle doesn't go up high enough to compensate if I clamp off the fuel line a bit.
I know the duty cycle should be between 30% and 40% at idle, but mine seems to be 22%. I can't find an explanation for a duty cycle that is too low.
Also I checked, but with the Autel I can't do a fuel pump test unfortunately..

Today I was checking some stuff again with the Autel after seeing this video and noticed my fuel gauge was at 0, but the tank is more then half full and got the code CEM4A37. When cleared the meter went to the right value again. I had this fault before after I chenged the o-rings in the tank. Cleared it and didn't come back, untill now.

So I guess I going to check the connector on the fuel pump again as I took this of to do the o-ring and check if I can find a fault in the ground connection. Because I think the level sensor and pump share the same ground.

Fingers crossed!

[jonesg]

you could disconnect the battery and apply straight 12v to the pump. He only got 42 psi on the old pump.
The new pump was over 100 psi.

[RuudKoster]

I will do that tomorrow.
I just did another live test with the Autel and made a screen recording. I saw that under full load the requested pressure was above 500 kPa and the actual pressure dropped below 400 kPa..
So if I give the pump the 12v directly and the pressure is to low, it must certainly be the pump.

[jonesg]

thats enough to trip the fault code.

[vtl]

Check all ground and supply voltage connections for oxidation, in engine bay, around battery and under the driver side panel in trunk.

[RuudKoster]

So I checked all connections and they are good.
I put 12v directly on the pump and the maximum achieved pressure is 600 kPa. So I will order a new pump!

[vtl]

So I checked all connections and they are good.
I put 12v directly on the pump and the maximum achieved pressure is 600 kPa. So I will order a new pump!

Read the fuel pump duty cycle first. Bad pump has it at 60+%

[RuudKoster]

Yes, I know. But I don't have VIDA and my autel shows 0,22% duty cycle at idle (see my initial post)