Hi all!

I'm new to this forum, but I have searched the numerous Immobilizer threads and cannot find one with the same issues I am having, since most of the ones I've seen don't crank.

(I bought my 2011 S40 T5 about 3 months ago from a used dealership. It has around 65,000-ish miles on it)

I went to start the car yesterday morning and it struggled to turn over. I think I tried twice. I got the message "alarm service required". I thought I had maybe left something on and it just drained the battery a bit, because the keys worked and all the lights/radio came on. I will note: my battery died about a month ago, I had AAA jump it (no problems) and I got the same message about the alarm. It went away shortly after, so I just figured it was a funky thing with the electronics or the battery dying.

When I went out to leave work 8 hours later that day, it again struggled to turn over and stay running. This time I got the message "Immobilizer. Try start again" and the engine would sputter and cut out almost immediately after the message appeared. This is the only message it gives, and I have no lights on my dash. Finally it cranked and turned over on the third attempt.

It still struggles to completely turn over today. I've tried unlocking/locking 5 times, I tried using my other key, etc. Nothing seems to completely solve the issue. . Any ideas? Thanks!

 

there's also a battery in the alarm system - its possible that could be causing problems. try searching for some posts on alarm system battery or similar topics. The alarm system battery is charged by the main battery and if it shorts can wind up draining it.