help - relocate PEM?

peripatetic · Post by **peripatetic** » 05 Oct 2023, 08:30

replacing the PEM on my 2004 v70 to fix stalling & fueling woes. figure that might as well relocate it from exterior (top of metal tank) to interior.

have “new” PEM (bosch 30769225) that i pulled from a wreck. other threads on MVS indicate that this should work as a drop-in replacement for original (bosch 30636431) PEM.

viewtopic.php?t=87748

questions:

1. can someone point to routing and rewiring instructions for moving PEM interior? couldn't find thread on this.
2. assuming old / new connectors are same but grateful for any advice on modifying / replacing harness.

Post by **vtl** » 05 Oct 2023, 09:11

Need a new harness: https://www.fcpeuro.com/products/volvo- ... o-30798596

https://f01.justanswer.com/Eclayton4/d1 ... module.pdf

Post by **cn90** » 05 Oct 2023, 20:02

Just carry a known good PEM in the trunk as spare and you will be fine.

What destroys these PEMs is simply aging process and electronics.

Even PEM from factory that is inside the trunk fails too.

My 2004 V70: replaced with a newer PEM ending with 30769225 a few yrs ago and all is still fine now.

Post by **erikv11** » 05 Oct 2023, 20:53

Exterior location is purported to reduce PEM lifespan. Carrying a spare could make for a pretty difficult replacement on the road if the PEM is still on top of the tank? Given all of the input, I'd definitely relocate the new one to the trunk since you must swap at this time anyway.

I just replaced the PEM harness on an 07 XC70. The three connectors in then small harness are for:

1 - car wiring harness
2 - fuel pump
3 - PEM

Before purchasing a harness I would suggest go through the trouble of pulling the rear seats (note: will set an SRS code if the battery is connected!) to eyeball the connector on the fuel pump end of the replacement harness: look at the pic of the part online, and make sure it matches the fuel pump in your car. There are more fuel pump connector types than shown in vtl's very nice pdf. Had I gone by the parts indicated in the catalog at FCP I would have ended up with mismatched fuel pump and harness. In fact check the wiring harness connector too while in there, too. It's also under the seat.

Is that part number from vtl the proper harness for a metal tank?

Post by **vtl** » 06 Oct 2023, 07:29

I think it is for plastic tank. Metal tank in NY? Was the car brought from CA?

peripatetic · Post by **peripatetic** » 22 Jul 2024, 16:12

vtl wrote: ↑06 Oct 2023, 07:29 I think it is for plastic tank. Metal tank in NY? Was the car brought from CA?

my car has a metal tank. yes, original owner (not me) purchased v70 in california.

v70 has been running like a top (for 10 months) since PEM swap. stalling, fuel starvation, and bad A/F mixtures… gone. as a bonus, my gas gauge - which was regularly over-reporting remaining fuel - is now on the mark.

a confession! PEM is still under the car. relocating it remains on the growing to-do list, but thanks for the tips & the help.

Post by **jonesg** » 22 Jul 2024, 18:13

my v70 is 2004 too but i find no PEM, i had it on the lift, gave it a really good look but don't find anything.
Do some 04 have no pem?

Post by **cn90** » 22 Jul 2024, 18:14

Even for metal tank, replacing the PEM is easy, lying on your back with no need to lift the car up.

I posted the trick re 7-mm screw in forum.
It is NOT 6-mm as one YouTube video says.

As long as you have a 7-mm socket, you are OK.

Post by **scot850** » 22 Jul 2024, 19:30

There are 2 locations for the PEM as you guys have mentioned. The one is on top of the RHS of the fuel tank or in the spare wheel well on the RHS of the spare tire. Some were relocated, from under the floor to the spare wheel area, I think there was a relocation kit to do that.

I may be wrong, and the newer Volvo websites are now often wrong on what cars parts are fitted to. But as far as I recall all P2 cars from 01 on had a PEM fitted.

Neil.

peripatetic · Post by **peripatetic** » 24 Jul 2024, 12:17

jonesg wrote: ↑22 Jul 2024, 18:13 my v70 is 2004 too but i find no PEM, i had it on the lift, gave it a really good look but don't find anything.
Do some 04 have no pem?

hi jonesg. echoing / expanding what scot850 wrote.

PEM for 2004 v70 is most likely on top of gas tank (@ front-right outermost corner). volvo relocated them in near subsequent years, and the PEM in many 2004-2005 cars was retrofitted / moved into trunk.

at junkyard, i’ve found PEMs relocated to wall of spare tire well, and also behind removable panel at lefthand interior corner of trunk area.

also, my best understanding is that any P2 PEM should work. i pulled a clean interior-located PEM from a 2006 S60 and dropped it into my 2004 v70. works great.

best.