['89 5.0 LX]

1989 5.0 Mustang LX. When accelerating, check engine light illuminates briefly. OBD code reader indicates '031- EGR positioner sensor below minimum voltage'. Is this an electrical problem or a mechanical problem with the EGR valve?

[jim293]

Welcome lets try your question in this section.

[89coupe]

It could be either one. Usualy its the EVP sensor on the back of the EGR valve.

Was this code a KOEO code you retrieved?

['89 5.0 LX]

Yes, it is a KOEO 31 code.

[89coupe]

Make sure you have 5v between the orange wire and black wire, and 5v between the Green wire and black wire on the EGR electrical connector with it unplugged from the EGR valve.

If not, clean the 10 PIN connectors behind the intake. Hook them back up and run the KOEO test again.

You also need to run the KOER test.

If so it looks like the EVP sensor is faulty.

['89 5.0 LX]

Getting 5v between orange wire and black wire, no volts between green wire and black wire. All connectors look clean and tight. Trying to run wires for shorts- can't see anything obvious.

[89coupe]

Clean the 10 PINs first.

['89 5.0 LX]

Did clean and reattach the 10 pin connectors and that seems to have corrected the 'check engine' light problem! Thanks for your help!!

[89coupe]

Now if Reggie would give me a raise!

No short jokes either old man.