P2 PEM checkout?

iastoddard · Post by **iastoddard** » 10 Nov 2019, 22:27

I have a 2007 XC70 throwing a P0089 code. I have replaced the sensor on the fuel rail, and the fuel filter. I am in the middle of system component checkout and am looking for PEM diagnostics. I have googled and found nothing helpful. My PEM is in the spare tire well, so probably no corrosion issues.

Can I check it with a multimeter, or do I need an oscilloscope? If former, please lead me to specs? If latter, do I need to get VIDA? I am in Houston TX and would love to talk to someone local about VIDA. I am retired so saving money is paramount.

Post by **cn90** » 11 Nov 2019, 00:57

Checking the PEM off the car is very very difficult.

Your best bet is to find a good used PEM (ebay, junk yard, good known PEM from another car) and swap over.
If the swap fixes the issues, you know the answer.

PS: The corrosion is internal (on the circuit board) of the PEM.

Post by **abscate** » 11 Nov 2019, 08:52

There are details and discussion in the XC90 forum Under user shockwave.

This includes links the o scope waveforms for the CEM ECU and PEM electronics

viewtopic.php?f=9&t=84648

Pull your part number and edit the title so we can search for it here, too, please!

iastoddard · Post by **iastoddard** » 11 Nov 2019, 20:33

Thank you to @cn90 and @abscate for the good words.
I will try to source the part from rockauto.com or a pick-and-pull.
I have to wait for the 17th to get funds$$$$ for this experiment.

As for the oscope readings, yikes!

I will put part number data in the title as soon as I have it.

Post by **cn90** » 13 Nov 2019, 13:23

The current price of a used PEM on ebay is about $35-$50. Search for a reputable ebay seller.

If you have access to junk yard, then it is about $15, which is what I do: getting spare parts from junk yard in case I need them.

I have stopped going to jy now bc I think I collect too much junk...lol...

There are sellers on ebay that go to jy to buy important parts for cheap, and sell on ebay to make a living...

Post by **oragex** » 14 Nov 2019, 05:52

The one in the trunk its protected from corrosion and also sits vertically so flakes from under the cooling plate wont fall over the control board. But as above, any used one that looks very clean will work, cheap to test. If you have a junkyard close, the second gen S40 V50 has it under the rear seats left side under the insulating material - these are the cleanest