OK, so I got the code and did the search on the forum but still have some questions.
1) Will replacing the valve body solve my problems?
2) Can I replace it without removing the trans from the vehicle?
3) Any suggestions?

 

ok so you have the P1870 code. you're lacking details, so, what symptoms are you experiencing?

 

1) If, after following the flow chart exactly as written, the result specifically instructs you to replace the valve body, it will fix the problem.

2) Yes, it can be replaced without removing the transmission.

3) Follow the flow chart, https://blazerforum.com/forum/diagno...plained-18227/