Scanner- 4l80e Pressure control

I have an on going thread in the LS section but since this pertains to 4l80e's in general I may as well post here.

I have been dealing with the chatter on my 4l80e in 1st gear. Fresh rebuild, HD-2 and a 3600 stall (fairly tight though) 411 pcm with the 4l80e segmant. Turns out last year I didnt notice I had all the MIL's and Faults set to know. I forgot to copy the full diagnostics segment. Other than the 1st gear chatter at 140 degrees the thing drove/shifted beautiful. As soon as second gear hit the chatter was gone. Almost feels like slipping a clutch that is destroyed.

So I reactivated all the codes, drove it this year and it pretty well put it in limp mode, shifting like crap, chattering around 110 degrees and I came up with a P0713 (temp sensor) and P0748 (Pressure control solenoid). I replaced the internal harness which fixed the P0713, but I still have the P0748. I should have tested this when I had the pan off.

Is there a good way to test this via the scanner? I activated all of the EPC pids, figuring with the Key forward it would show the resistance, im getting nothing though. I triple checked all wiring to the PCM etc.

I have also hear this issue occurs with higher stall converters BUT usually comes and goes.

Any ideas?

Thanks