OBDII / CAN Question!

If your OBD2 scanner is PC connected, you can send commands by using a terminal application. You will need the commands for the unit you purchased, as well as the specific command for the HHT, which I do not know. Which OBD2 scanner did you purchase?

 

The important one that is missing is KWP (fast init, 9.6 kbaud). The Prius uses it for option setup on the Gen2. The Gen3 uses CAN for options, but still uses 9.6 KWP for the TPMS.

 

Check out the treads that talk about the ELM 327. The genuine ELM is a custom programmed MicroChip PIC computer that supports all of the protocols that you mentioned. The chip itself is available for about $30. When it first came out, they didn't set the copy protection on it, which allowed other people to copy the code. Since the PIC computer chip costs maybe $5, this allowed other vendors to build clone copies and sell the entire package for less than the original chip.

So everybody except the original developers get a deal on the package, right? Not exactly. There have been a number of improvements on the original, and the copy protection mechanisms are turned on. So if you want a version that works the best, you have to get a device with the $30 chip in it. Or I suppose you could get a $30 device, separately purchase a genuine ELM 327 chip (another $30), and solder in the new chip. Or you could purchase one properly set up for $75+.

I've never tested a genuine ELM device, so I can't tell you if it works with the Prius or not. I've certainly tried to make my $30 clone work, and failed. The $6000 devices that Toyota dealerships use do work.

There's no technical reason that a $30 device like the clone ELMs couldn't be made to work with the Prius. The problem is that the people who know how to do it want a lot more money for their services.

 

There are plenty of ELM 327 devices on EBAY. I have on I purchased there. I use my AutoEnginuity with the Toyota module for $400.00 Here is what it does:
Toyota Engine Module List