s14 fuel pump relay question
89 M3 S14 race car....
came in as a no start, no fuel pressure....
tested system and found fuel/02 relay ground trigger not getting ground from the ecm pin #20 brown/yellow. I can ground the wire right at the ecm ruling out a wiring issue. car runs fine with this grounded, no other issues.
tested for power on 2 main relay wires at ecm 35 and 18, starter wire power to ecm (#4), all have battery voltage when expected.
My question is.....what inputs does the ecm require so it can send ground to fuel relay on pin #20?