I agree that the overall directions are a bit disjointed and this product would greatly benefit from 1 cohesive "2024-2025 LEXUS GX550 TUNING INSTRUCTIONS" document. The instructions should be written exclusively for the specific device - apparently VF Tuner makes a "WiFlash" device and a "Legacy" device and we all have the WiFlash device. I have no idea what a Legacy device is and I had no idea that I would have to distinguish between a WiFlash and a Legacy device. The instructions should also be written only for the vehicle for which you purchased the product.
This is a typical case of the instructions evolving over time and incorporating more and more vehicles, tunes, devices, etc. It's also a classic case of the VFT guys being too deep in the product & process - it's all crystal clear to them because they are the experts and they know what they're doing but we are diving in cold. I'm pretty good with the mechanicals but I have never delved into software tuning or coding before. This is all Greek to me.
After digging through the various links and guides, the process I ended up following was:
1. Download the VF Tuner (VFT) Software and Drivers onto your laptop.
2. Find the unique serial number for your specific device by connecting the WiFlash module to your laptop with the USB cable and then plugging the
WiFlash directly into the OBDII port under the dash. Open the WiFlash software on your laptop and get the serial number. Email the serial number to VFT at
support@ovtune.zendesk.com.
3. Receive confirmation back from VFT that your device is now registered, re-boot the VFT software with the same USB & OBDII connection described above, then IDENTIFY (not READ) the ECU details of your vehicle. I then emailed back my ECU ID and vehicle details to VFT.
4. VFT then emailed back their 2-part email where the actual flashing of the tune takes place:
There are two (2) parts to this email:
Part 1: Reading the ECU so you have a stock file
Part 2: The Tune Files
From here on out, you will need to install the CAN Connect cable to your vehicle (attached in this email is the guide) and your WiFlash device should be connected to that CAN Connect device for ECU Read and Flashing. This is where you have to get behind the dash and remove the blank plug from the CAN connector and plug in the VFT adapter. I had no idea where to find this plug - VFT's email said a guide was attached but I've had problems all along finding and opening VFT's attachments - as munkeeboi already mentioned, the attachments are embedded in the emails and they don't show up like every other attachment I get via emails. I found thangcu35's photos posted earlier in this thread and that showed me what I needed to know.
Continuing with VFT's 2-part email, still on part 1:
This ECU can be read. Please redo the ECU Identification process, and then the "ECU Read" button should be available.
After the read process, there will be a window that will pop-up asking you to name the file and save to a folder in your computer of your choosing.
Save the file. This will be your stock file. You can flash this in case you need to go back to stock in the future for any reason. My ECU read went on for about 10 minutes with the progress bar a bit past half-way, then I received an error code "Unable to receive ECU Block!" and everything froze up. After another 12 minutes with no change on the progress bar the vehicle shut down to conserve the battery and I disconnected the USB cable and re-booted the VFT software and tried again. I got the same error message immediately.
I emailed VFT and they had me use the
DIAGNOSTICS TAB in the program and click the "dtc / clear dtc all modules" button under Toyota gen4 options. Worked perfectly and cleared all codes. VFT further informed me that
since your ECU is an already supported ECU you do not have to read it you can flash the tunes. In other words, I could go straight to part 2 of the 2-part email and start flashing. Then why did their instructions tell me to start with Part 1?
Now on Part 2 of their email:
=== PART 2: TUNE FILES ===
Attached with this email is the latest calibration files that we have for your vehicle's ECU ID.
The files are in a .ZIP or .RAR format in order to compress the files and save space. You will have to decompress/extract the files. There are videos online on how you can do this. You may need to download a free compression program like WinRar or 7zip.
Again, I couldn't find the attached zip file at first and I had to open their email in a separate window to find it and download it. Then you extract the zipped tune files and save them in the VFT software master folder on your computer (there's 6 tune files: 1 each for 87 octane, 87 octane plus TCU which I assume means transmission tuning, then the same 2 options for 91 and 93 octane).
Then follow the VFT software menus to flash. Follow the instructions and click the
WiFlash icon, click
Calibration File and find the tune file that you saved on your computer, then click the
Flash button. I chose the tune file named
6AG40 8A2226025300 91 Octane OTS + TCU Version 3.vfc which I assumed was for 91 octane gas and it also contained the transmission tune.
Then as a final step I used the
Diagnostics tab to clear the fault codes that arose again. And it's done! I can definitely tell that I am now tuned.
In summary, the various instructions and guides contain a ton of info that has nothing to do with this Lexus GX550 WiFlash tuning device. Just remember that we are the
Toyota Gen 4 3.5L 2.4L Turbo. It would be much clearer if we had clear & concise instructions referencing the "2024-2025 Lexus GX550." It should really be cleaned up to make this much clearer and easier. VFT guys, I hate to admit it, but you need to speak to some of us like we are children completely new to the world of ECU tuning!
