Having some trans issues. Where to start.

[NSperduto]

2004 with a 48RE. Last year or two the truck was having some late downshift from 2-1. (I don't drive the truck a lot) I bought a transducer and selonoid and dropped it off at a shop of a friend. I asked him to flush the trans, and change the tranducer and selonoid. He did that but also said there was a piece of snap ring in the pan and thought because I had 180,000 miles on it I should put in a new trans. Instead I took it home and was going to change the snap ring in the over drive unit. The housing was cracked so I wound up putting in a rebuilt overdrive unit. I started driving the truck again and the truck still had the late downshift from 2-1 but I drove anyway. Fast forward a year and about 10,000 miles later. Tonight, now the truck won't downshift into 1st gear, automatically or manually. I scanned the computer and have a P0868. I couldn't clear it with my app. The fluid is full. I've read more about people saying to replace the selonoid and transducer and about the GM upgrade. But I would think if it were those I'd still be able to manually shift it into first?

Any suggestions or help would be appreciated.

 

[cerberusiam]

It is likely the transducer again or the VB harness. The solenoid just reacts to what it is being told unless it jams which if you have the older style it could. You can try transducer and solenoid again or even the DNC aftermarket manifold with the GM style solenoid. I have one and only thing I need to do periodically is replace the transducer.