Some users reported that they got a problem connecting Toyota Proace 2017+ with Techstream. There is no Proace in the vehicle list. Try different techstream cables (mini vci, mangoose, vxdiag vcx nano toyota) and software versions, all the same.
Here is the clue.
Toyota Proace van is based on a PSA platform. Toyota Proace is a Peugeot Expert and Citroen Jumpy. PSA made Proace for Toyota.
For ProAce project TME has decided the adoption of PSA technical documentation and diagnostic tester.
So you cannot find Proace in Techstream. You will need Diagbox.
Techstream is for all Toyota and Lexus except Supra and ProAce. Supra needs Toyota ISTA* and Proace requires diagbox.
Where to download/get Diagbox for Proace?
Check and download ISTA & Diagbox license for Supra and Proace here.
*Toyota ISTA (which is based on the BMW ISTA) is a seperate software package from Techstream but it does need Techstream installed. It’s specifically for the new Toyota Supras since they’re made by BMW and have different ECUs.