99' S70, 5-speed, Immobilizer Problem. End of the road for Matilda?

[850 LPT]

There appears to be emulators available for some Volvos to replace some parts when there is no start. I used an emulator to repair my Mercedes with an Electronic Ignition Switch problem. I had to do a lot of research to find information and a source in the US that I trusted.
volvolugnut

Thank you lugnut, I have never heard of emulators but it sounds intriguing.

Sounds a little like something I would use when I bake bread

Dirk

[abscate]

Here is how a 1999 OBD talks to the ECU

IT first goes into the driver instrumentation module or DIM, see yellow lines

The green lines follow it out into the ECU , module 4/46 by number.

Any wiring fault between these will look like a bad ECU

The DIM to ECU path isn’t as bad as it looks, these diagrams have every option of engine management shown, your car will only have one of these. I tried to label on the DENSO ONES IN BLUE

[abscate]

Much better picture on the engine management side…

[xanthefin]

"My mechanic tells me that he can program a NEW immobilizer, but they are NLA at the dealers."

Yes these can be done i just want share. You need PIN code for old one and command clear the sync between ECM and IMMO through IMMO3 box. This is stated in Volvo own literature that old one is required if want fit new virgin Immo box so ECM is in clear state to accept new IMMO3 box. If want follow Volvo dealer official path replacement.. in your case if cannot be communicated then it states you need new ECM too.
There is microrelays inside IMMO3 box listen if you can hear them when you turn ignition on as it cuts ECM and Immo3 box talking so they can talk in private for little moment. Some models doesn't of Immo3 but i seen them so far SV40 models by now.


CDM on 99 and 00 models has no communication between IMMO box so i don't have idea if CDM is required and i not heard from other hackers of IMMO3 it would talk anything else than ECM additionally led output used for VGLA box to tell it ok or not okay key.

CDM and ECM communication of anti theft thing i am not personally familiar but interested learn if there is such.


But there is always unofficial ways remarry some..
Honestly i would blame ECM still having some bad days.

[scot850]

Seems to be the case with much of Volvo's electronics where you have to buy and new part to replace a broken one. Can't use a used one as the programming is a one shot use. It was the same with the DIM on my 00 R. Had to buy one to fix it but fortunately the original one was just suffering a loose connector.

Neil

[scot850]

Is the immobilizer unit the small box on the LHS of the steering column or the larger one above the LHS footwell?

https://www.volvovancouverparts.ca/a/Vo ... 70680.html

Is this #2 on the drawing above?

Neil.

[xanthefin]

Is the immobilizer unit the small box on the LHS of the steering column or the larger one above the LHS footwell?

https://www.volvovancouverparts.ca/a/Vo ... 70680.html

Is this #2 on the drawing above?

Neil.

Yes it is #2 the brain of Immo. Either in Black or Blue colour. Around near steering column.. SV40 models has it way easier on almost next to bonnet leveler. It is secured on 850 extra plastic which need be removed first then you can use flat head screw driver pry it off from metal casing (has bended metal tab holding it other side just -- slides off then but being careful with connector on top not yank too hard).

And as you now mentioned i have once heard loose connector on either antenna or to that #2 box having loose pins which could be checked if not yet.

This is stupid but you can get these immo fault codes when you have bad fuel pump. I think logic behind of this is ECM resets and doesn't get Immo message when it does reset but Immo wont reset (Ignition hasn't been turned off - on cycle yet).
https://ozvolvo.org/discussion/12876/im ... er-problem

[850 LPT]

Thanks for all the info guys. All good stuff although it makes my head hurt.

My indie is still working on this. He will examine for rodent damage on the harness. This was pointed out to me by abscate and it makes sense to pursue since the car sat for about 6 months with a bad clutch hydraulic line. Then it has been sitting intermittently until now.

If this doesn't bring about any results, then I will bring the car home and start investigating with abscates help. Or rather follow him and try to learn

He has a matching set ECU, Immo, Cluster and keys from a 2000 m56 V70. Those parts should slip right in. For testing I could tape the key on the antenna ring and remove the chip out of my key.

Dirk

[abscate]

Are we sure the black 4/19 box is immobilizer or just keyless entry? I’ve labeled it here but suddenly getting cold feet on this

[xanthefin]

Use socks so no cold feet

Volvo literature uses 4/22 for Immobilizer and 4/19 for Remote controller (VGLA) Alarm box's Receiver unit top of Dashboard.. VGLA unit itself is 2/76.

Gonna collect them all.