Honda Civic VX failed NOx, EGR system not working

I have a 1993 Honda Civic VX (non-Calif model). I am having problems
passing a smog check because NOx values at 15MPH are too high. I know
the problem lies in my EGR system. The EGR valve is not opening
because the EGR solenoid valve does not receive a signal from the
computer (ECU). I have verified the operations of the EGR valve and
EGR solenoid by jumpering a direct wire to the battery. When I do
this the EGR solenoid and EGR valve opens and everything works great.
I do NOT get any Check Engine light to help me narrow down the
problem. Any help is greatly appreciated.