94 Sentra XE 1.6L with AT

at the COIL SIDE of fuel pump relay, with ignition switch on, there
is positive voltage at terminal 1 of relay but at terminal 2 which is
the
"ground" side of the relay, there is no ground and the relay cannot
close, hence no power to fuel pump.

traced the black/yellow "ground" wire back to the ECM, pulled
code for MPFI which indicated EFI system was normal (5 long
& 5 short blinks).

WHY WOULD ECM NOT ALLOW FUEL PUMP TO OPERATE
WHEN (IT THINKS) SYSTEM IS NORMAL???

MUST I REPLACE ECM?