VF Tuner ECU/TCU Tuning for the GX550

[munkeeboi]

Unfortunately, flashing between tunes cannot be done on the fly. You will need an internet connection, the wiflash module and a laptop each time you want to swap tunes. Depending on how you wire your canbus cable, you may need to pop the side panel open as well

But if all goes according to plan, switching tunes shouldn’t take more than 10 min

 

[Bluegill]

Report from halfway from my trip. Mileage is slighly better +.5 mpg on this trip compared to last. Avg speed was 70 mph on cruise control. Plus side is this better mileage is after installing the westcott lift. Interesting part is that I went 346 miles before the gas light went on. My fill up when it clicked off was 17.6 gallons. Hmmmmm…

What size tires are you running?

I can't believe you are showing 17.1 mpg on the dash and went 346 miles and filled up only 17.6 gallons. Did you have your wife out back pushing the whole time?

 

[munkeeboi]

Running 275/60/20 (~33”)

It’s LA to Sacramento so it was a combo of up and down hill stretches. Trying to understand it myself. I know I topped off before leaving, but not an additional 4-5 gallons.

 

[VF Tuner]

Running 275/60/20 (~33”)

It’s LA to Sacramento so it was a combo of up and down hill stretches. Trying to understand it myself. I know I topped off before leaving, but not an additional 4-5 gallons.

even our 4 cylinder hybrid land cruiser barely sees 15mpg...

 

[rrk]

I live in Washington state where we only have 92. Which tune to run 91 or 93?

 

[munkeeboi]

91 tune? I'm figuring you can always go over what the tune is rated for, but never under.

 

[VF Tuner]

I live in Washington state where we only have 92. Which tune to run 91 or 93?

91 octane tune.

 

[Bluegill]

The CAN connect for my gx550: hope this helps
View attachment 9552View attachment 9553View attachment 9554

Thank you for posting this - I could not find any info on connecting the CAN cable on VF's website. Getting the blank cap off and then getting the CAN cable connected is a major pain.

I got everything connected and I zip-tied the flash device back there like thankcu35 did in his pictures above.

I tried reading the ECU and ran into some errors. Now I have a check engine light and multiple system malfunctions. Not going well over here. I shouldn't have tried this on a weekend!

 

[VF Tuner]

Thank you for posting this - I could not find any info on connecting the CAN cable on VF's website. Getting the blank cap off and then getting the CAN cable connected is a major pain.

I got everything connected and I zip-tied the flash device back there like thankcu35 did in his pictures above.

I tried reading the ECU and ran into some errors. Now I have a check engine light and multiple system malfunctions. Not going well over here. I shouldn't have tried this on a weekend!

Email us and we will get your covered, even on the weekend

 

[Bluegill]

email sent before I posted here

Safe to drive? I need to drive to my son's soccer game! I don't care about the nanny sensors, just want to make sure I'm not going mess anything up with the Check Engine light on (or get stranded....I'd never hear the end of it from my wife).

 

[thangcu35]

email sent before I posted here

Safe to drive? I need to drive to my son's soccer game! I don't care about the nanny sensors, just want to make sure I'm not going mess anything up with the Check Engine light on (or get stranded....I'd never hear the end of it from my wife).

lol no worries, I’m sure most of us had to change underpants at least once when going through with the flashing session. VF will get you straight though.

 

[Bluegill]

All good, will clear the faults and try to flash in a bit!

I'm a long-time Land Rover guy so I'm no stranger to fault codes...but I'd never hear the end of it from my wife it's self-inflicted on my new toy.

 

[Bluegill]

All good now, I do believe we are tuned.

 

[Mojobaggins]

Going thru the process and so confused. Been emailing with support, I was sent a guide to connect to the OBD2 port to get the ECU ID. And that's where I am.

Emailed support with the ECU ID and didn't hear back. Emailed them again and they said they emailed with all of the info and attached calibration file and that they were attaching the directions and file to this email. And got nothing but links to pdfs to connect the CAN connect cable and read the ECU flashing guide.

Wish there was a complete set of directions.

Am I close here?
1. Connecting to the OBD2 port to pull ECU ID and email support with it.
2. Connect via CAN connect cable and read/download Lexus ECU file?
3. Flash ECU(thought the flash bypassed the ECU) with the calibration file they send you? And is the Template Toyota Gen4 2.4 / 3.5 Turbo the calibration file?

 

[Mainelexus]

please let us know what you find out. I was under the impression you had to hook up the Can cable for things to connect to, not use the obd 2 port.

 

[munkeeboi]

Going thru the process and so confused. Been emailing with support, I was sent a guide to connect to the OBD2 port to get the ECU ID. And that's where I am.

Emailed support with the ECU ID and didn't hear back. Emailed them again and they said they emailed with all of the info and attached calibration file and that they were attaching the directions and file to this email. And got nothing but links to pdfs to connect the CAN connect cable and read the ECU flashing guide.

Wish there was a complete set of directions.

Am I close here?
1. Connecting to the OBD2 port to pull ECU ID and email support with it.
2. Connect via CAN connect cable and read/download Lexus ECU file?
3. Flash ECU(thought the flash bypassed the ECU) with the calibration file they send you? And is the Template Toyota Gen4 2.4 / 3.5 Turbo the calibration file?

You can get the ECU id by plugging the wiflash device directly through the obd port. All other reading and flashing needs to be through the CANbus cable behind the side panel.

Once you have the tune files, You read your existing ECU through the CANbus cable and make a backup of your stock Ecu settings.

Once you have your back up made. I went ahead and restarted the car to make sure the car didn’t time out on me during the flash (happened me the first time I flashed and ended up needing to recover my ECU). Flash the tune using the wiflash on the CANbus cable. Use the vftuner and clear any errors when done.

As for the support emails, Check for a response from support. When they got sent to me, I recall the tune files and support instructions were imbedded in the email and were not be separate attachments. Check your spam folder

 

[Bluegill]

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!

 

[munkeeboi]

Hopefully, they just take your post and add pictures to it. Well done.

 

[Mainelexus]

Thank you very much Bill. It would be great if VF would chime in and let us know if we can all just skip to step two, or if we should still be trying step one. I guess I am not sure how you would flash back to stock if you don't save your original ecu programming on the computer.

 

[munkeeboi]

Apparently, flashing through the canbus, you cannot brick your ecu.