Confirmed equipment was in hard lock out on service code 2 flashes on the RTRM LED 2. The ignition module was not calling for any heat therefore no diagnostic LEDs or flash codes and normal operation only on the RTOM driving the plenum fan assembly Confirmed y1 and y2 cooling calls with no operation of any modes. Per tech support, lock out #2 could be related to any add-on accessories, cooling mode, or heating mode. Diagnostics can only be led in one direction with DC voltage testing during lockout. After resetting the equipment all systems appeared to run normal. Cycled system back and forth at least 3 to 4 times between heating and cooling and high and low stages. All operation appears normal Air filters are an acceptable condition Repaired loose connection at the flame sensor and resurfaced sensing rod. Confirmed high stage cooling mode running at 39°