Defender 90 2004

hi new to the site, I have a defender 90 2004 and the brake/abs/TC lights are coming back on after the they go through the test sequence and staying on, I have had the hand brake switch off and cleaned it up and made sure it's adjusted correctly. I have checked the wiring behind the dash, cleaned the earth cables next to the ecu, checked the fluid levels, brake pads ok, lost to what it is help!

ByB