My fuel alcohol composition is reading 78% on my 2009 Tahoe 5.3 Flex.

A quick search on Google tells me I can't reset it without a GM Tech2 tool or the like. There's quite a few Chinese knockoffs online, but I have no idea what is the best one to get. Anybody have any experience with these that can point me in the right direction?

Thanks in advance!

Edit to clarify: I have two 2009 vehicles. I'm also about to take delivery of a 2023 GMC Sierra. It looks like there is the Tech2 and something called a MDI. What's the difference? If I understand correctly, the Tech2 won't work on any vehicles after 2013. If I go with the MDI, will it work on the '09s as well as the '23?

You're correct that the Tech2's updates stopped with MY2013. I have a chinese clone Tech2 that reads and programs my GTO's systems just fine. My "expensive" ThinkPro scan tool can't read the GTO's BCM which I suspect is due to the Tech2's candi interface.

MDI runs on computer based software and may require a subscription from GM to access all the features. The Tech2 is a stand alone device that has all the software built in unless you need to program modules. Then it'll connect to a computer

If you just want to reset the flex sensor, this comes with Tech2Win and works fine. It may take a little playing around with to get to work, but it's ~$300 cheaper than a Tech2 clone. I've used it to reset the flex sensor on an LS swap before.

https://www.amazon.com/gp/product/B0743BFLXB/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

If you think you'll be working on multiple years/brands of cars, it may be worth stepping up to a prosumer tool instead of the MDI clones. They're only $200-400 more expensive than a clone Tech2 and work well with most newer vehicles. Autel has some tools in the $600-900 range with bidirectional controls.

This Thinktool dongle also does bidirectional controls but IDK if it'll work to reset a flex sensor. Might be worth asking the seller. I've been tempted to buy it for $100

https://www.amazon.com/Thinkdiag-Bluetooth-Bidirectional-Diagnostic-Functions/dp/B08YWTJY4F/

Thank you! Great info.

I've inquired with the seller on that last one. Will post up the answer I get.

Todd 02 said:

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Thank you! Great info.

I've inquired with the seller on that last one. Will post up the answer I get.

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I'm curious what they say! I think the Android app is very similar to their tablet app and the bluetooth dongle/MDI looks very similar to the one they sell in their more expensive prosumer scan tools that don't include a J-box.

I'll say, Think's support hasn't been great. I reported the GTO issue back in June. Received a response they were working on it and nothing more. There was a big GM update in August so I tried it again. Still says the BCM isn't on the can network and can't read it. Submitted another support request. Got another message on the scan tool saying they were investigating and would email me. So far, no emails, and it still says they're investigating.

Granted, the GTO is a *******ized GM product since both Holden and Pontiac are dead so I don't expect much support there

If you reset it, will it stick?

Toyota 5.7 FFVs had this issue for 2-3 yrs and all the DIY solutions appear to be temporary and get reset by the ECU in pretty short order.

Ethanol Composition was 78%.

Bought the device txyaloo recommended and was able to perform a relearn. Ethanol Composition is now at 3%. My scanner is no longer throwing codes for fuel being too rich.

Will monitor and post results.