How do you replace the PCM on a 1994 Ford Tempo GL?

[Mark]

THE SERVICE LIGHT COMES ON MY DADS CAR AND THE CODES THAT COMES UP SAYS, EGR VACUUM REGULAR AND EGR LOW FLOW AND MY DAD CHECKED THE EGR VACUUM REGULATOR AND IT'S FINE.THE CIRCUIT HAS NO GROUND WITH A TEST LIGHT AND THE WIRE GOES TO THE PCM(SECONDARY REGULAR,TOO) GOES TO THE PCM.HELP US WHY THE LIGHT IS ON CONSTANTLY ON THE DASHBOARD WHILE DRIVING.

 

[Mr. KnowItAll]

Unless your car got hit by lightning, I doubt the PCM is damaged.

If you're getting "EGR VACUUM REGULAR AND EGR LOW FLOW " then replace the EGR valve, and clean the ports.

 

[Jeffrey]

Just because the egr looks good the diaphragm could be bad or the port could be blocked i would replace the egr valve