Yes the EVR (electronic voltage regulator) has been known to go bad but since your ESS is not sending a signal to the PCM you need to find out why.
Are you getting voltage to the ESS ( it should recieve 5 volts from PCM)?
Do you have a ground? One of the three wires is a ground wire if not getting ground you need to add a remote ground wire.
power wire=violet/white
ground wire= black/light blue
signal wire= gray/black
I just checked the wires and have
power wire=violet/white ======= 5 VOLTS
ground wire= black/light blue === 8. 45 VOLTS
signal wire= gray/black ======= NO READING WITH ENGINE RUNNING
Should I be getting any kind of a volt reading from the signal wire