DS3 BSI issue - anti theft faulty

[CGlen]

Hi all,

I have a 2016 DS3 that I purchased in February. Since owning the car I've had nothing but issues with it. It's been in the garage more than it's been out!

First issue was ESP/ASR faulty and brake lights stopped working. I had a brake sensor replaced and it seemed to work.

Multiple issues after this but won't bother going into detail.

The most recent issue which started back in May was an intermittent Anti-Theft faulty error message upon starting the car, and on occasion, the car wouldn't start. Took it to a french specialist and they said I needed a new battery as it was really low. Replaced the battery and the problem was still there. They then said I needed a new key so got that. £400 later and after waiting a month for the key I picked it up last week and the issue is still there. They're now telling me it's the BSI that's faulty and I need a new unit that will cost £700!

I wanted to get some opinions on whether you guys think this is the actual issue, or whether it could be something else? At this point I'm not sure I trust the garage. When asked if I could just get the unit repaired they said no. I've asked a couple of companies that do repairs/cloning and they've said it should be fine and quarter of the price of a new unit.

I want to sell the car and have a couple of people interested so really want to get this resolved asap but not sure what route to take and don't want to spend £700!

Thanks in advance.

[PaulC5]

When you have the message, if you leave the key in the ignition and open the driver's door do you get a message warning about the key - if not then possibly the key is not being recognised by the immobiliser. This could be the aerial pick up around the lock is faulty or possibly its wiring/connector. Did your French car expert do a diagnostic before replacing parts ?

[GiveMeABreak]

Try this first, which contains the reinitialisation for the fobs / keys

BSI Reset / Battery Disconnect / Reconnect Procedure

[CGlen]

When you have the message, if you leave the key in the ignition and open the driver's door do you get a message warning about the key - if not then possibly the key is not being recognised by the immobiliser. This could be the aerial pick up around the lock is faulty or possibly its wiring/connector. Did your French car expert do a diagnostic before replacing parts ?

Thanks for your reply. I'm not sure, I will have to check this. Weirdly the error message hasn't come up for a few days, it's very intermittent. If/when it pops back up I'll check the door and see. Yes, they did a diagnostic and said that the battery was low so to replace that. That didn't work straight away do they then just said it was the key. They didn't say anything else showed up on the diagnostic. Annoyingly they told me to use the spare key in the meantime, but the error came up with that key too. I told them this but they just said to wait for the new key that was coming from France and then they'd reset/reprogram all the keys. They tried the key multiple times over several days and the fault never showed. As soon as I got in it came up straight away. On Sunday it was fine driving out then coming home the error came up every time I put the key in the ignition, but the car seems to be starting each time. Since then it's been fine but I just feel it's going to pop up again at some point.

[CGlen]

Try this first, which contains the reinitialisation for the fobs / keys

BSI Reset / Battery Disconnect / Reconnect Procedure

Thanks for this. Would the garage not have done this when resetting the keys? I'll give it a try.

[GiveMeABreak]

Probably not!