history first

apologies I'm very new to all this I've a 2006 RRS it has had new suspension all round and compressor fitted by the local car dealer 6mths ago I bought it from while still under warranty. issues at first the suspension light went red after further investigation the compressor was not compatible wouldn't code to the car for some reason so the old was put back on no issues suspension wobble went.

now I do have issues.

orange suspension light comes on daily turn engine off it goes for a while then appears again. fault code UO434.
ive also noticed the compressor kicks in every time the car is started up first time and runs for a bit.

I took it to LR who reset the codes said it was all fixed to find nothing has changed now the new excuse is "it must be wiring fault " bring it in we will fix it £££. any help or advice would be much appreciated or if another thread has already been done can you post the link I searched for the fault code nothing came up.

thanks all