Relocated Ecu now m+s lights?

Just spent the whole night relocating the Ecu into the glovebox, I disconnected the battery installed new extension harness, re-attached battery and the m and s lights are now flashing?

Battery is putting out 12.8 volts and the when engine is on 14.3 volts. And it has had recently a new xyz switch

Could this just be that the Ecu has been disconected and needs a reset?

Any info please

I had m+s lights on mine a while ago. After searching on here I decided it was likely to be one of two problems. Either the xyz switch or a low battery. I decided to replace the battery as I had not had the car for long and therefore didn't know the state of the battery, although it started the car without any problem. This cured the lights.
If you have had the doors open for quite a while while relocating the ECU, is it possible that the battery is the problem? Apparently the 'box ECU is really sensitive to voltage drop. Try an overnight soak charge and see what happens, or if the battery is quite old would it be worth changing it anyway?