Not Starting on first turn and Service Theft Deterrent System

[Vx-Mad-G]

Hi Guys,

Need your help folks.

A month or so ago, I was getting a random "Service Theft Deterrent System" message coming up randomly and my start/stop wasnt working.

So googled it and everything pointed towards a dodgy battery, especially as the start/stop want working.

Anyway, I replaced the battery for another good second hand one and low & behold, the start/stop started working so that nailed that S/S problem. However randomly I was still getting a "Service Theft Deterrent System" message.

Anyway, over the last week or so, on startup the car wont turn and the same "Service Theft Deterrent System" pops up. You take the key out and try again and we are absolutely fine with no message. If you simply turn the key to off and the turn it wont start, you have to take the key out completely. However, I have also noticed now that my start/stop has again stopped working again since this issue has started.

So, any pointers please? Cannot be another dodgy battery can it?

Any help appreciated.

With regards,
G.

[Rusty2009]

I only had this happen once no idea what caused it.

My advice is to plug it on and see if any error codes are stored.

Other than try changing battery's in the fobs.

[Vx-Mad-G]

Thanks. With regards to the fob, thats exactly what someone else advised, so we're trying the spare key currently. Will report back how this performs. Fingers crossed.

[Vx-Mad-G]

Update. So I have been running the car for over a week now with the second key and not had the same problem.

So although the issue seems to have gone away, whats wrong with the original key?

[Rusty2009]

Did you change the battery in the original key?

Failing that you could try reprogramming all keys.

[Vx-Mad-G]

It went for a service, and apparently the battery was changed, makes me think now that it wasnt!! Ill try that - but not confident reprogramming the key myself, in case I brick the whole thing!