New TPMS Activation

[kismetus]

Do the TPMS sensor require >1PSI and activation before they go live?

 

Purchased sets of (New/NOS) clamp-on OEM TPMS. I'm trying to test/activate before installing to save time and money. I've several that fail to activate using MaxiTPMS TS201 and some that do. I'm working on a jig to prove it to myself in any case - empirical data based on experience or technical doc's would be helpful