I found that a temporary fix for this problem was to remove the horn relay and wire a separate horn button, but I FINALLY found a permanent solution. The cause (which I discovered on a European Volvo discussion board) was that the rechargeable batteries in my siren module were failing and had trashe...

One other thought based on a lot of Internet research when my car wouldn't start (the CEM was shutting off the fuel pump but no immobilizer warning) You may be getting conflicting signals to the CEM from your siren module because the rechargable batteries are dead, or are eating up the curcuit board...

When I picked the car up from the Volvo dealership, they had flashed the SRS module and plugged the relay back in, and the car is running fine. Total bill was $55.00. They warned me that they just fixed the symptom and probably not the problem. The SRS module was getting a signal that the car was in...

I took the car to my local indy shop that has an Autologic system and they were able to read all of the codes but unable to reprogram the CEM. There was an SRS code-00D3 that could be causing the problem. Very nice guys and no charge for this visit! So I bit the bullet and had the car towed to my Vo...

Oops! Sorry I didn't notice it was a T6. Hope it's something simple.

There's a freeze plug in that location that has been known to pop out. If you search for "freeze plug" on this forum you might find a thread about it (or Google S80 freeze plug). It's a fairly easy fix. Also check to make sure your oil separator box isn't plugged, causing excessive crankca...

I've been dealing with the same thing, and found that I could remove the fuel pump relay and put in a switched jumper and the car runs. That means it's an CEM problem. Last fall, my dealer reloaded my CEM software as a recall, because the car had been stalling. He said at the time that the variable ...

I made a simple jumper with a toggle switch to go across terminals 3 and 5 on the CEM (what would be the lower horizontal lugs on the relay) It's not switched with the key which is why I added the toggle switch, so the fuel pump isn't running with the car off. I can switch the fuel pump on and start...

I just checked the voltage from the CEM that latches the fuel pump relay and it's 10.8V. The relay latches at about 5V on the bench, so there's either not enough amperage out of the CEM to latch the relay or a poor ground. CEM time? I give up.
I'll let you know what the dealer says. - Reid

No immobilizer messages, and the car just stopped on the road like it was out of gas. Also no OSB-II codes.