Im having. Problem with my car have a 2004 s40 t5 it started a couple of weeks ago with the ignition switch not shutting the car right away , then it i could remove the key completely and the car keep running then after a. Few seconds shuts off . The i started noticing that when i locked the car the headlights would turn on after a minute or so . I replace the ignition switch today and the key works great it shuts off right away but when i locked the car the headlights and all the relays started going crazy after a minute and 30 secs or so if anyone can help me plz i. Would really appreciated thanks Danny

 

Looks like CEM issue.
I think after minute and 30 seconds CEM tried to save state before go to sleep.
So there can some issue and as result CEM restarts. That is just a guess.
Also the bad battery can cause this. Check voltage at the time you see the car going crazy.