Code 31 on a 1990 for 5.0
I have been stumped on the code 31. I have replaced both
the egr and the egr sensor but I still I'm having code 31
come up. I have checked to see if they got power and they
do so I don't know what is going on.
in the diagram, egr, three wire connector. The wire that is primarily black is ground. The wire that is primarily orange is 5 volt ref. The wire that primarily brown is signal. As you can see, several sensors share the same ground. Two other sensors share the same ref voltage as egr. A problem with other sensors on shared circuits might cause a problem with egr? You can digital multimeter to check voltage, ref voltage and signal. Make sure no exhaust passages are clogged.
