Durbs

Hi all hope some of you knowledgeable lot maybe able to help me?, just bought my 2nd D3 this time a HSE that's previously been converted to springs. I was totally fine with this and not an issue for me as less to go wrong in my book. Upon pick up from the dealer 2 minutes down the road the Disco seemed to slow ..... brake itself like abs engaged and pulled to the side slightly then the amber triangle came on and said suspension fault on the dash? I carried on driving and got a series on gongs telling me not to exceed I think 20/30 mph for said fault but drove ok and didn't lock up etc again but the light remained on. Went and got some essentials from the supermarket and again on set off did the same then drove ok minus the do not exceed said speed. Now before I go ranting and raving to the dealer like a mad man I've looked over certain threads and people have mentioned the SAS could need re calibrating?..Is this correct or could it be something more sinister? Drives ok other than this issue! Any advice or help would be massively appreciated. Regards Paul