2005 V70NAM56 No start condition, prelim diagnosis 30742823 Topic is solved

Post by **matthew1** » 17 Jan 2018, 12:57

abscate wrote: 17 Jan 2018, 08:15 PS - off topic - what kind of car warns you that the FPCU is going one week before two long trips by futzing out 1/2 mile from home, then getting you home, then promptly quitting again making diagnosis in the driveway easy?

A car who loves you.

BTW, "2005 V70NAM56" is the highest information density ever in a title here at MVS. ~13 characters and we have a wealth of information to start with. If MVS had an Information Density Trophy™, you'd get it.

Post by **wizechatmgr** » 18 Jan 2018, 10:32

This morning's festivities attached...

: steven.PNG (37.28 KiB) Viewed 1876 times

Car has about a 5 PSI variation from the pump at idle until it warms up.

Turned fuel pump on from VIDA and on the 3rd or so attempt, she fired right up.

Post by **jimmy57** » 18 Jan 2018, 11:18

There is a board soldered relay for fuel pump in CEM. It is the source of power on A16 at CEM. On your car it feeds PEM. You can check it with voltage drop between pos post at engine fusebox to CEM A16. Not a high failure rate that I am aware of but 2005 is the first year of P2 CEM II so it is the oldest and the age related failure, if any, may now be showing up. Monitoring A16 should be done when pump runs. Also a good idea to run a wire that you back probe into A16 and check voltage there at several starts and while running to see if there is no voltage or low voltage there to determine if that is the problem or you focus on no command to PEM, PEM, or fuel pump.

Post by **abscate** » 18 Jan 2018, 12:36

Thanks Jimmy.

That explains a lot. I kept seeing references to the fuel pump relay but no such animal appears in wiring diagram, since it’s internal to the CEM.

Without VIDA I was able to get to fuel pressure sensor, pump ekdctronics module, or fuel pump as cause

VIDA now tells me to check fuel pressure sensor, PEM, or fuel pump.

Gotta love it!

Post by **abscate** » 19 Jan 2018, 07:18

I think next step for me will be (warmer weather next week) removing the PEM and inspecting for corrosion and also monitoring the 12V Feed to it from the CEM.

This is a steel fuel tank V70 , by the way, which VIDA says is not eligible for the PEM relocation into the spare tire well. Hmm. I wonder why not?

Post by **abscate** » 20 Jan 2018, 12:48

Nailed it

Checked voltage from A16 CEM to PEM and it was perfect at B+

Pulled and opened PEM and it was full of crud

Cleaned with electronics cleaner and car started

New one on order

Post by **RickHaleParker** » 20 Jan 2018, 14:34

Pulled and opened PEM and it was full of crud

Too much leakage current. Did you figure out where the crud was getting in and seal it?

Post by **abscate** » 20 Jan 2018, 14:36

Post by **abscate** » 21 Dec 2018, 07:05

If MVS had an Information Density Trophy™, you'd get it.

I received the trophy this morning Matt, and I understand to keep the engraving costs down you acronymmed it to

IDIOT

Post by **oragex** » 21 Dec 2018, 07:55

All used PEM fit all cars from S60 XC90 S40 etc from early 2000 up to about 2012 for the S40. Late S40 have them inside the car under rear left seat unde the carpet corner away from humidity. On those located outside, corrosion builds on the cooling plate and
damages the circuit board inside. By the way these are pretty funny to split open as the cooling plate is attached to the circuit board with several welds, I think a heating gun is needed.