Early this year everyone here with gracious help pointed me in the direction until we found slide valves wore out. Rebuilt them and she has run like a top until this evening. I got a call around 6 circuit A is tripping on code 190 low superheat. I couldn't sleep so went out tonight to check it out while it's cool and quiet no one to bug me.

On startup the unit runs for about 30-45 seconds not long enough to get any stable system readings then shuts down pops 190.
All condenser fans are working cocrrectly and the coil has been pressure washed every quarter by me.
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All of the readings below were taken with the machine off and about 2-5 minutes after it tripped out

I think the Evap refrigerant pressure sensor is where the majority of my trouble lies but please double check my logic. I used a brand new sman 2000 for all psi readings I took for this.

Sensor 1 evap refrigerant temp sensor reeadings taken at the access port 3 inches in front of the sensor but behind the exv I read 98 psi on my gauge manifold and at the UCM I was reading 175psi for evap refrig press. my assumption sensor toast wo removing sensor to do full test as per trane TSB.

Sensor 2 compressor suction temp. 98 psi actual reading on svc valve at compressor. Pt chart conversion shows 58 degree at 98 psi for r-22. The UCM was displaying 77 degrees suction temp. My thoughts this sensor is out of calibration as well.
Did I use the correct train of thought for sensor 2 diagnostics.

Sensor 3 condenser refrigerant temp sensor. 165 psi reading on my gauges the UCM showed 166 for condenser refrigerant pressure.
Based off my findings this sensor is AOK.

Sorry for the novel but after reading through this It's looking like evap refrigerant temp sensor and compressor suction temp sensor are out of range and the cause of my problems.

Just wanted to bounce this off a few others and get feedback or suggestions. Again I apologize for the length of this.