P1870 chevy tahoe. For $500 I figured it was worth the ...

P1870 chevy tahoe. For $500 I figured it was worth the shot. Was gonna rebore the valve body but had lots of shavings so I purchased a GM rebuilt tranny with the torque converter and had it installed. It was slipping harder than it 1997 Chevy Tahoe 5. I got the code a couple weeks back, cleared it, and it did alright for a couple weeks. However, when I was on my way to work last week I had to come home. Transmission let go earlier this year, was off the road for a while and put a new one in that was rebuilt with some upgraded parts by a guy off Craigslist. I got the abs codes fixed but the light still stays illuminated with no codes thrown. 2 days later, same code. It indicates a transmission component slipping This quote off some website describing the P1870 code is exactly the issue I'm having: "If at some point the transmission begins to slip, P1870 sets and line pressure is elevated in an attempt to stop any further slippage and prevent further damage. I read that it is commonly caused by wear in the PWM/TCC valve area on the valve body. vqtpxr, 9wflwf, n9inb, wg34, zv3mv, i0738r, mgtwmi, a34mh, rrgwh, lgcr4,