I have the engine code P1870 on my 1997 Chevrolet Blazer

Question

I have 230k miles. rebuilt tranny 34k miles have P1870 code. Shop says they if the valve body was replaced with the tranny rebuild, they cannot replace it again. Just want to verify if that is so.

Answer 1

P1870 Transmission componenet slipping

If it is a rebuilt transmission you would usually see this code condition, it mostly the seal at the torque convertor that cause this code. The transmission rebuilt should be under warranty,

Answer 2

P1870 CHEVROLET - Transmission Component Slipping

Read more: https://www.autocodes.com/p1870_chevrolet.html