What exactly does the engine immobilizer system do when it is activated? My wife and I were messing around with her key (the battery was almost dead in the key) and then the next day the car wouldn't start using that key. It turned over (strong - I don't think battery is a problem) but it seemed like their was no power to the fuel pump. Is this what the immobilizer does - cuts power to the fuel pump? Or if the immobilizer kicked in because of us messing with the key would the car not even crank over? Just trying to trouble shoot before taking it to the garage. Thanks!

 

What about your key, you do have two keys, right? Also a problem with the immobilizer system will throw a diagnostic trouble code. Have it read and post back with any codes found.

 

Only have one key unfortunately Right now this is our only car so we can't go anywhere to get the battery replaced in the key. Will have a ride later tonight. I was just curious whether this was a complete coincidence or if a problem with the key would shut down the fuel system but still allow the engine to crank? I would imagine an engine immobilizer system wouldn't even allow you to crank over the engine but maybe I'm wrong?

 

Also I did read the manual, particularly the section on the key, and it talks about the engine immobilization system but doesn't really clearly explain how it works - i.e. whether it prevents you from turning over the engine or if it disables the fuel system but allows you to crank the engine. Thanks for your help

 

Update - got the correct keyfob battery and once installed in the key the car started fine. So I guess the answer is yes, this anti-theft system operates by somehow disabling power to your fuel pump. We were trying to start the car with just the bare key and the inside part of the key removed. Hopefully this helps anyone else that runs into a problem with this - glad we didn't tow it to a garage!

 

Thanks for posting back with the resolution . Glad you figured out with a cheap fix.