I am having problems with my shift solenoid B.

My cel throws Shift solenoid b, both solenoids have been replaced. From what ive heard this can be caused by something with the ignition module? or a connector on the power wire?

Before replacing the ignition module is there something I can check? The problem arose not long after having my heater core replaced, and I am thinking something was messed up when removing the dash.

car shifts through 1st and 2nd fine, then gets to 3rd and comes out of gear, before slamming into 3rd, then it has to slam out of 3rd aswell. how it acts depends on what type of slope i am on. then once i come to my first complete stop after this has happened the car only operates in 4th gear.

The car is in near perfect condition other than this problem and I need to get it fixed because I bought this to flip.

 

I am having the same problem with my trans 1st and 2nd sometimes reverse hardly ever I took it to the shop got a quote for 1400 can anyone give me.any insight to save some
money