I recently obtained a mini VCI cable and techstream software to perform some dealer 'customizations' that I've been wanting on my own car. I have a 2006 Lexus GS300 Cypress Pearl and another 2016 Lexus IS200t Ultrasonic Blue Mica 2.0.
Normally, you get one session with the dealer for free when you buy the car new. I bought my car used and wasnt keen on paying a dealer to do this so I bought the tool myself.
I order mine from fobdii.com for about $20 bucks. Mine just came in. Firmware 1.4.1 running on win10 64bit.
This is the one I ordered, http://www.fobdii.com/wholesale-498-mini-vci-single-cable-for-toyota.html . I only needed to turn off the DRLs.
Wowzer. I found some code stored for the ABS, low or high power supply voltage and a malfunctioning humidity sensor circuit. It showed me my transmission codes before they popped up as actual MILs. Included freeze frame data too.
Update - I've played with the cable a bit more. Looks like I have the ability to register new TPMS! I'll have to wait until my new sensors come in.
It'll do all the personalized settings and diagnostics but it won't reprogram the ecu, create a new key or register new tpms sensors. I also obtained the latest techstream for my 64bit system. FYI: The cable comes with a mini Techstream software CD, but i don't use the software, I find myseelf a good place to download v12.10.019 software together with mvci driver, registration key and manual etc.
Here's the link:
https://drive.google.com/drive/folders/0B-3Zt8Mtu_YDN1VCQ2VNU2luS3M
It's a diagnostic tool to help pin point the issue or customize certain settings. It pretty much a more advance OBDII code scanner but for Toyota\Lexus\Scion. Car Diagnostic Tool You can clear the DTCs and see if you issues will come back. Not only can it do customizations, but it can do some in depth diagnostics and scans.
The greatest parts about Techstream is the code it reads from the stored memory even though it doesn't throw a light on the dash. It also depend on the cable. The cheaper cable may not program a TPMS sensor, program a key, or factory reset the transmission behavior but it should read from all the computers.
Update - I was able to register new TPMS sensor even though the seller claims it does not register new sensors.
Definitely a worthy investment if you like doing work yourself and have a stable of Toyota cars.