C4 MK2 battery replacement (alarm sounding when locking)

[stewalker89]

Evening,

I replaced the battery on my C4 Picasso yesterday after a warning on the dash was saying "electrical circuit fault have vehicle repaired" and the app was saying faulty battery.

I put the new battery on the car and followed the BSI reset details but the car is still showing the same fault code and now the alarm is sounding when I lock it.

What have I done wrong can anyone provide advice ?

[GiveMeABreak]

Did you follow this guidance?:

BSI Reset / Battery Disconnect / Reconnect Procedure

If so, then you may have a power / supplies issue that needs some proper diagnostics.

[wheeler]

Did you check the charge rate from the alternator, this should really have been done first, There may have been nothing wrong with the battery but it could be a charging issue.