2007 XC70 start problem

[Mpdog37]

This is far shot in the dark but an after market radio/ CD player was installed in this car previously, could this have any bearing on current predicament? Could this cause ground issue??

[Mpdog37]

More: retrieved old CEM, ignition switch, and antenna key ring from previous owner. He seems to think it is not the CEM. Supposedly, CEM was replaced with used module(out of running car) programmed with new key, along with new ignition switch and antenna ring installed. I installed new battery, new starter, pulled used CEM, used contact cleaner all around, brushed pins reinstalled. Still same thing, turns over 3-4 times then stops, however if bypassed using relay will turn over continuous. Most of not all interior accessories work. The dash reads DSTC on, brake failure stop safely, immobilizer check manual, very low tire pressure. Check engine light is on, as well as red triangle in center. Tried usual immobilizer free ups, lock/unlock 5 times, put in neutral turns over, then stops, turned to position ll and off 5 times, same thing ...even set alarm, opened door, and alarm went off, turned off with key fob no problem. Immobilizer still on. I tried switching out to old antenna ring tried again, no luck, switched back ring.
Question, how do you tell key is syncing with antenna ring? Do keys automatically sync, should ring light up,( does not appear to). Should it not turn over at all if any of key, ignition switch, ring were faulty?
This is my first newer Volvo, so the rabbit hole getting deep and running out of money.

[abscate]

On a 2007 car,modules are coded to the VIN of the car, so swapping modules from junkyards won’t work. Specially the ECM, CEM, DIM all need to be loaded with software specific to the car

Backyard mechanics won’t work on these cars. You need VIDA TO diagnose these problems.

[Mpdog37]

I understand, and supposedly that was done, reprogrammed you car and key, but sure doesn’t seem like it. Took directly to Volvo mechanic and could not read engine faults, suggesting new CEM, but cannot afford price. Would old CEM still work if reinstalled with ignition and old key and recognize car?? At Least I might be able to have diagnosis?
Thanks

[abscate]

You will need working VIDA to proceed or else it will be ice climbing in the dark, with your hand tied.

Its very likely the CEM programming wasnt done correctly and now neither of the CEMS/keys will index to the car. You just don't know, and VIDA is the only tool which will tell you.

[Mpdog37]

Man I am driving an old 850 right now and was looking to upgrade, should have put my money into that, starts right up every time, but could use a little love...will talk to my mechanic and see what he can do with old CEM, if hen get a bead on it, will post results thanks.

[Mpdog37]

Update; got old cem, ignition switch and antenna reinstalled. Immobilized is off, but brake failure still and now start prevented comes up on dtcs, as well as low tire pressure. I have 2 old keys, both open doors and locks, however one will show immobilized, and other shows start prevented. Since they open doors and turn ignition, I assume these are original cut for car, one with chip.
However, I do not have key fob, only 2 hard keys. Couple final questions before I move on from this nightmare trash heap ; could the key that gets “start prevented”, simply have bad chip and not be communicating and prevent start?
If so(yes, a stretch), could a locksmith still cut me a new key with responder chip to work with this vehicle, or better yet could he let me know the original key chip actually works to eliminate the prevent start scenario. The battery is new and has been recharged, but interesting note here. Battery light and “power system” popped up up after I reinstalled cem, so I put jump box on for boost just to make sure battery was not an issue. Jump box was fully charged, but when hooked to battery jump box went from green to yellow?? Could this be ground issue?
Also with newer cem etc(supposedly.reprogrammed with key and ignition) it said immobilized but cranked over and stopped, now no crank but prevent start. Does prevent start say old cem, ignition and key still being recognized? I am out of patience and money, so new key would be last ditch effort, or this beautiful car is going on the chopping block.
Thanks to all...

[abscate]

Well, you’ve found it why it was cheap.

Locksmiths can’t code keys to Volvo cars, you need a subscription VIDA ( not the software you buy on eBay)

With tow you will be into it for $500 to get this done.

[vtl]

You need to synchronize other modules with your new CEM, they are a part of immobilizer network. Replacing just CEM alone won't do it.

You can purchase pre-cut key from the dealer and program it yourself with VIDA Online or VDASH.

[RickHaleParker]

You can purchase pre-cut key from the dealer and program it yourself with VIDA Online or VDASH.

Cannot program keys with the downloaded, eBay or Amazon VIDA.

2007 XC70 is a P2, To program keys with Vdash he would need to copy the CEM bin file and send it to Vdash to to extract the CEM pin number. That requires opening the CEM, wiring a programmer to the CEM PC board.

As for a three day online subscription to VIDA. There are a lot of people that say an individual can do a 3 day subscription but, try to find an individual that has done it recently and you will come up empty.