Here's the deal, I'm literally stranded 2100 miles from home, came out to visit someone for 2 weeks back in August, car died, things went south and here I am, still stuck 9 1/2 months later. When the car first died I got the "Immobilizer-See Manual" message. It would crank for about 3 seconds then stop, I would have to turn it all the way off in order to get it to do it again, if I turn it to "On" first, it just clicks, I have to turn it all the way off and go straight from off to "start" in order to even get it to crank over for a whole 3 seconds. Everything seemed to point to the CEM, so I got a new one through XemodeX hoping that all my issues would then be resolved, installed it, and same thing, no such luck. Had it towed to a shop about 2 miles away that supposedly has worked with Immobilizer issues with Volvo a few times and supposedly has the equipment to scan Volvo, got a call from them this morning and they can't figure it out either, said there is no communication with the ECM, CEM, BCM, TCM, etc. I've ben thinking lately that it's the actual key itself, as maybe the transponder in it went bad. Problem is I've now been stuck here 2100 miles away where I barely know anyone and am running out of cash and options fast and need to get this issue resolved, 9 1/2 months is way too long to be stuck so far away from everything I know. I've never had a car stump me like this before. This has been far beyond frustrating.

 

If a scan tool won't communicate with a group of modules you may have a problem with the Can network - You will need a pretty smart guy to figure this out, and might end up testing continuity on the can wires. Could be a bad module "shorting out" (putting wrong or false signals on the network)

Probably not a key - don't suppose you have another to try? If you don't have a spare it would not be a bad idea to get one (a valet key is cheapest) but that requires a VIDA subscription (usually a dealer) and the car and key have to be at the dealership (or the shop that has a Vida subscription) A key is not going to prevent communication between modules.

A dealer would be able to fix it - but that will hurt your wallet, badly.

Diagnostics with VIDA is really the only way to go. Several choices there from the stolen/hacked free version (that you can't do downloads with) to a subscription.

 

Yeah, only had one key when I bought this thing back in '19. The weird thing is how it will crank for about 3 seconds at a time, but I have to turn the key all the way back off in order for it to crank again, for only about 3 seconds. I've never seen a car do this. It did good for this 2100 mile trip across the country but then just started with this issue when I was about 123 miles away from my destination, after spending the night in a hotel, just wouldn't start the next morning, so I rented a trailer and trailered it with my friend's truck the last 123 miles. Everything seemed to point to the CEM but that apparently didn't resolve the issue, although it did resolve a few of the other issues I had, such as the left side low beam now works. After replacing the CEM it now has a new message that shows up along with the other messages, now also shows "Rear Power Port in use" or something along those lines, but nothing is, or has been plugged in to that one.