P0745 error showing on a newly installed CVT transmission on 2008 versa

Question

The dealership just installed a new CVT transmission in my 2008 versa due to P0745 code.
After installation they informed me that it's still not fixed now due to a faulty TCM. They wanted to charge me for a new TCM as it wasn't covered by the warranty. I told them it was expensive which they then replied that they can put a used one for half the price.
It doesn't make sense to me that they didn't figure this out initially when they were doing their diagnostic. If it was an issue with the TCM wouldn't it's code show up as well rather than just showing the P0745 code?
Was this an attempt to take me around the block??
Can anyone please shed some light on this & a possible fix.
Thanks!

Answer 1

P0745 Line pressure solenoid valve

This is the problem when you are dealing with a solenoid , whether they are in the transmission or solenoids in the engine. When a solenoid fails and it is not resolved soon , it can burn out its driver in its computer . You replace the solenoid . when you set a P0745 the transmission , replace the transmission. its cost effective and either way the TCM will get damage