I called Autel TPMS support and they told me the reason the sensor won't program is because I need to renew the license for my MP808TS. I don't see how they can tell that with the error code -1. That is basically an unhandled exception in the programming world.
The last time I had TPMS issues with my Autel scanner, their support person told me the TPMS section for my scanner was supposed to include free lifetime updates. After that, they turned a knob on their end and my TPMS program started working normally again.
That being said, I have 2 options now. I can go buy a brand new hand-held TPMS tool for a couple hundred dollars and get free lifetime updates, or I can pay $650.00 US to renew my MP808TS license to allow the tool to download the TPMS updates that are free on the significantly-cheaper hand-held tools. I don't really understand what Autel is trying to do here, because I think they are making the majority of their TPMS profits on the sensors, not the scan tools. This is why it makes no sense for them to deny the free lifetime updates they told me were included with my MP808TS ($1000 US). All they have accomplished by denying the free updates is the loss of an MX-sensor customer because now I have to go back to using pre-programmed OEM sensors instead of buying their expensive Autel sensors. Note: The Autel diagnostic program and the Autel TPMS program do not run in the same process on my tool. I can only run one of these programs at a time on the MP808TS. If either one is running, I have to exit that program before I can launch the other.
As a part-time mechanic, the price of the Autel annual subscription is prohibitively high for me. I work on older vehicles, so I'm fine with the functionality of the scanner as it is. However, Autel has made a change to the MX-sensors that is not backwards-compatible, which (apparently) is why my tool will no longer program them. That is wrong. They should either make the new sensors backwards-compatible, or call the new sensors "Version 2" or similar so we can still use our TPMS tools without an expensive upgrade.
The takeaway here is it doesn't make good financial sense to buy an Autel scan tool that includes TPMS functionality because you can get free lifetime updates by purchasing the significantly-cheaper hand-held units that will never require additional license fees. If you work for a business that is willing to pay the annual extortion fees, then by all means buy the scan tool with an integrated TPMS program.
I'd also like to mention another thing I've learned from talking with Autel support personnel. They tell me I purchased a non-US version of the MP808TS. That was a shock to me because I purchased the tool from Motorzone on Amazon USA, and they claim, "Motorzone is the main legal distributor of Autel." I was told yesterday in a very flippant manner that Autel has NO AUTHORIZED SELLERS ON AMAZON.
I purchased my MX-sensors from The Autel Store on Amazon USA. The Autel support person I talked with yesterday told me that store is NOT AN AUTHORIZED SELLER for Autel. All of this leaves a bad taste in my mouth. I am now looking for a different brand of scan tool for my shop, and will no longer use the MX-sensors going forward.