mitsubishi ABS & brakes issue

hi all i have a 2002 pajero petrol 3.5 ltr. i am having problems with the brake light and ABS light coming on , the brakes still work fine but not the ABS ( that realy does not bother me ) anyways have replaced the accumilator , checked all tollerances for the wiring ( ass per mitsubishi specs ) and all conuity , checked all the relays every thing . when the coputor is coded it comes up with a code no 55. which is pump motor circuit . now every thing works the motor is pumping as per norm every thing seems ok . to get the lights of i put the key in lock pump the pedal 40 times to empty accumilator , turn the key to on , alarm for brakes come on, pump comes on builds up pressur , arlarm goes off. start car all is fine till you use brakes a few times or use the ABS system , lights come back on what the ! . after sitting over night put key to on alarm comes on , pump starts pressure builds up all is fine ,then as desribed before all starts over again . please any mitsubishi techs got an answer.