1998 V70 2.5T Manaul Swap ECU compatibility

[P80joan]

Hello everyone!

I’ve finally come around to register at MVS after years of lurking.
Thanks for all of your (indirect) help so far!

I have an 1998 V70 2.5T FWD (B5254T) that I want convert to a M56H. The mechanical side seems clear to me, it’s just the “software stuff” I can quite wrap my head around…

I’m aware the topic of ECU compatibility has been talked over a lot. But I hope it’s okay to open a new post regarding my specific case.

From what I’ve gathered, swaping the ECU to an equivalent manual one is the best way to go besides reflashing (sadly it’s very hard to find someone specialized in flashing Volvo ECUs in Switzerland).
Now I have the (in my location) rare option of getting parts from a donor car, also a 1998 V70 2.5T - but a manual.

Will swapping my current auto ECU with a manaul one work plug and play?

Bosch ECU Part Nr.
current auto ECU: 0 261 204 457
donor manaul ECU: 0 261 204 456

I’ve read from a lot of posts that the ECU numbers must be identical, but also seen sources that seem to idicate that the differt last digit refers to the transmission.

And another thing: Do I need to swap the keys, locks and ignition switch antenna togehter with the ECU the get the immobilizer to work?

Help would be much appreciated!

Thanks a lot
joan

[xanthefin]

If donor ECM is at donor car you can empty it from immo via its own original immo before throwing to new system without hassle.
In other case.. there is ways yes like making it non immo ECM or then manually marrying them together.

Edit: for future lookers.. this info actually mostly not fit for M4.4!

[P80joan]

If donor ECM is at donor car you can empty it from immo via its own original immo before throwing to new system without hassle.
In other case.. there is ways yes like making it non immo ECM or then manually marrying them together.

Thanks for the reply!
The ECU is not in the donor car anymore and the engine is missing so I can’t get it to communicate with the immobilizer, I think.

If I swaped out all the keys and locks with the ones from the donor car, will the donor ECU work without clearing or pairing the immo? I don’t have the tools and software to do so sadly.

Cheers!

[xanthefin]

If donor ECM is at donor car you can empty it from immo via its own original immo before throwing to new system without hassle.
In other case.. there is ways yes like making it non immo ECM or then manually marrying them together.

Thanks for the reply!
The ECU is not in the donor car anymore and the engine is missing so I can’t get it to communicate with the immobilizer, I think.

If I swaped out all the keys and locks with the ones from the donor car, will the donor ECU work without clearing or pairing the immo? I don’t have the tools and software to do so sadly.

Cheers!

Requires original IMMO* with ECM too change then sadly if you cant go software flashing (to make ECM use US software.. or other ways..). So not ECM alone.

Then changing locks and ignition lock is sure one way.. or dig the chip out of keys and move back to "new" old one.
Or if knew PIN code for IMMO to rematch key to system so just using old key.

PIN is too required if want clear ECM from the original IMMO via easy way so if planning that way later again.


I belief other people here who done this kind of job can share their experience as i am more to software ways ( if ever interested there is no need fancy tools as long you get PIN code from dealership i think i can help any way i suggested if have Android phone and good elm dongle interface ).


*Immo is located near at steering column -- right side where ignition is, its either blue or black box hidden a bit at annoying place. Breaks your neck. No need change antenna just that box.

P.S. I assume now as from Switzerland that both has IMMO like EU usually does. If not then my talk can be ignored.

P.S.S I am kinda sure people has some simple method for ECM run on manual as i forgot completely the goal of project.

[P80joan]

If donor ECM is at donor car you can empty it from immo via its own original immo before throwing to new system without hassle.
In other case.. there is ways yes like making it non immo ECM or then manually marrying them together.

Thanks for the reply!
The ECU is not in the donor car anymore and the engine is missing so I can’t get it to communicate with the immobilizer, I think.

If I swaped out all the keys and locks with the ones from the donor car, will the donor ECU work without clearing or pairing the immo? I don’t have the tools and software to do so sadly.

Cheers!

Requires original IMMO* with ECM too change then sadly if you cant go software flashing (to make ECM use US software.. or other ways..). So not ECM alone.

Then changing locks and ignition lock is sure one way.. or dig the chip out of keys and move back to "new" old one.
Or if knew PIN code for IMMO to rematch key to system so just using old key.

PIN is too required if want clear ECM from the original IMMO via easy way so if planning that way later again.


I belief other people here who done this kind of job can share their experience as i am more to software ways ( if ever interested there is no need fancy tools as long you get PIN code from dealership i think i can help any way i suggested if have Android phone and good elm dongle interface ).


*Immo is located near at steering column -- right side where ignition is, its either blue or black box hidden a bit at annoying place. Breaks your neck. No need change antenna just that box.

P.S. I assume now as from Switzerland that both has IMMO like EU usually does. If not then my talk can be ignored.

P.S.S I am kinda sure people has some simple method for ECM run on manual as i forgot completely the goal of project.

That’s very helpful, thanks!

Now I know what the immo is and can take it from the donor car. Swiss models should be the same as EU.

I guess my best bet is to get all possibly needed parts anyway and then try out to see what works once the project is started.

Still curious about the different ECUs being compatible, let’s see if there’s more info out there.

Thanks a lot!

[Goupil]

If donor ECM is at donor car you can empty it from immo via its own original immo before throwing to new system without hassle.
In other case.. there is ways yes like making it non immo ECM or then manually marrying them together.

With a 98 are there any immo issues with ECUs ? I thought the immo was just sending an ok/not ok signal to the ECU
I've swapped two different 456 (2.5T manual ECU) in my immo equiped car and had no issues.

Now running a tune based on the 607 (North american T5 ECU), so the ECU is just ignoring the immo all together

[xanthefin]

If donor ECM is at donor car you can empty it from immo via its own original immo before throwing to new system without hassle.
In other case.. there is ways yes like making it non immo ECM or then manually marrying them together.

With a 98 are there any immo issues with ECUs ? I thought the immo was just sending an ok/not ok signal to the ECU
I've swapped two different 456 (2.5T manual ECU) in my immo equiped car and had no issues.

Now running a tune based on the 607 (North american T5 ECU), so the ECU is just ignoring the immo all together

Well actually good you bring up and let me know a verification as i might have mixed up all this time! As makes more sense.. Fenix 5.2 has Immo which works on other Fenix 5.2 ECM's without problems though M4.4 i had belief as it being "better" than Fenix 5.2 in all way by even having active marriage between ECM and Immo which declines to work if not correct ECM (refer to my 40 series experience below).. BUT American ECM software is ignoring it all IMMO being even there.



There is data which can be found on ECM and IMMO. Two sections either way if active.
MSA15.7 has own IMMO area but not actually having either this data.

ME7 and 40 series ECM's though i can verify to have data in place both places.


On 1998 year 40 series i tested remove/replace data and it goes nah nah you dont start this and security led goes wild and sets up fault code for it being wrong ECM.



But actually M4.4 i cant verify fully and you maybe even right and i was wrong! Which explains too that..>>>

I forgot completely that on my M4.4 i tried couple times find this and i did not find this piece of marriage data anywhere yet unlike SV40 or ME7 which has data which matches on both (IMMO and ECM). MSA15.8 i haven't verified either yet.


To be noted though it might still check MIN code of the engine with the ECM as Volvo itself says its included in data exhange with the ECM and VIN code but the later one are usually only on 99 models or 40 series problems. Has anyone mixed different engine M4.4 ECM with different IMMO? Anyone?
I think i will try to do that test if i can. As at least my Fenix 5.2 IMMO wasnt happy at all.


I'll stand corrected



But for P80joan.. Forget though the ECM and IMMO marriage as i was wrong for this specific system having one. Try with original IMMO what it says though i put my slight reserves if MIN code is different still but i wont say for sure yet.

[misha]

My immo2 box wont communicate with vol-fcr and dealership scan tool and my plan is to replace immo2 box with it's matching key and try it.

Because of that...i'm unable to read & clear ecu M4.4 codes.

All other modules in the car communicate ok except ECC since it still produce flash codes,because they don't go through immo2 box.
On 850....ECU should only see a "green light" from immo2 and key.
As long as replacement immo2 box and the mathching key have the same numbers like the old one...it should work.

S,v,c,xc70 from '97-'99 should be the same...but not sure.

For 850...i'm pretty sure that this should work and i'll try it soon.

[P80joan]

Thanks for the further replies, I really appreciate it!

So I checked my Volvo again and it definitely has the immo box under the steering column. The donor will have it too then.

Since I'm not willing to go to a dealership for immo-ECU marrying/matching, I've decided to just get all the possibly needed parts from the donor car (it's very rare to find one near me, let alone a manual).

Once I have the parts, I wan't to switch things around and see what works (then everything back to stock). I'll test the following combinations:

stock immo - donor ECU
donor immo - donor ECU
donor immo - stock ECU

My plan is to see if it starts and check for error codes. I'll post the results, hopefully that might help others out as well.

One important question before I do this:
Is there any risk of electrical/software issues when swapping around ECUs and immos?

Is it safe to start the engine with a possibly not compatible tune? (mine is still an automatic, donor ECU for manual; also different ECU numbers)

Obviously, I'll disconnect the battery and wait for 10min before swapping modules.
Anything else I need to do?

It's my only car and I need it working again on Monday (:

Thanks a lot!

[Goupil]

Sounds like the best idea, grab everything you can off the donor then try do as little work as possible !

Swapping ECUs that similar I wouldn't worry, the engine peripherals (turbo/injectors) are the same. Dont quote me on that but I think the manual tune does have some kind of limiter on the first two gears to avoid wheelspin/protect the driveline

Flashing is where it gets fun, sometimes the erasing work but then flashing the new tune doesnt. Not fun when you're doing that on your daily driver on a sunday afternoon

Xanthefin I have somewhere on shelf a matching M4.4 ecu and immo, also have a good elm + a vagcom with a flashing bench, I'm no software engineer but if you ever need me to try something on those I can