Check on the main board the number of cooling stages (ESC “3” Times > Scroll up to “Configurations Menu” > Enter > Scroll up to “Configurations Misc.” > Enter > Scroll up to “Configure # of Cool Stages” > Enter > Make sure the “# of cool stages” is 2) – If not Push up and change to 2 and press enter
On main board go Down or up until you are on “Diagnostics”?
Check Status Menu (On main board go Down or up until you are on “Status Menu” > Enter> Up push all the way up to “Colling Stages” > Enter > If Y2 has a number)
If Y2 is calling, go to your terminal strip and check the 24V Wire (On the terminal Strip Place you Voltmeter on “common” & “Y2” and it should read 24VAC)
Need to check Refrigerant Pressures (Put gauges on service ports on compressor) Above 50PSI