1994 s/420 dtc code help
 

hello all i have a 1994 s/420 with pse pump problem,s door lock will not lock automatly, with te button inside car checked 38pimn connetor pin 20 will not blink it,s just lite up like it stuck checked pin 21 and got code 37 whicth is voltage to low less than 9 volt,s can anybody tell me what ineed to correct this problemm any help is useful,,, thank,s