Sensor Based Automatic Flex Fuel - Sensor and Wiring Install Guide

sms2022 · Apr 23, 2024

Attached is a guide with full bill of materials and part numbers through summit racing for setting up sensor based flex fuel on a left hand driver 2018-2023 GT.

As far as I know, the only software that supports sensor based flex is PCMTec / @Rolls. This system will automatically adapt from pump gas to E85. It’s not a normal flex tune as it can be run full time and will run a full power E85 map if the sensor reads 85% ethanol. It interpolates between a 93 map and the e85 map for flex in between. @Rolls, please correct me if any of this is wrong and I will edit.

Several tuners offer tuning with PCMTec software but I cannot recommend Ray at @DRP Motorsports enough. First, he offers remote tuning for this setup and other than Lund was the only one doing so when I reached out to tuners earlier this year.

Second, Ray has been nothing but responsive, helpful, and nailed the tune on the first try. According to him I can run anything from 87 pump gas to pure E85 and the system will adapt. The car runs flawlessly on his tune and idles smoother than factory. DRP is also a forum sponsor and has many YouTube videos on PCMTec features running on his shop car, a whipped 2019 GT. You can purchase tuning right through his website

now for disclaimers/notes about my guide:

You will need/want PCMTec’s guide on their install in a RHD mustang as it has some good tips and clarifications.

Note: I am not a pro and I wrote this on my phone. There may be typos. If you note any errors or wants more clarification/pics let me know and I will revise. Install at your own risk. Triple check for fuel leaks! I checked every drive for the first 500 miles and now check every fill up.

note that nobody is paying me or offering me any benefit for doing this. I paid full price for tuning, full price for parts, etc. I wrote this because I just think it is an badass system that I would love to see more people run and have more features/methods become available as more people run it and have more ideas.

hope this helps everyone get into the world of sensor flex as it is far superior to the factory “inferred” flex that most tuners offer.

Juggernaut · Apr 23, 2024

Great work! Thank you for sharing

Rolls · Apr 25, 2024

Out of all the dealers we have dealt with Ray has been phenomenal to work with. I am not a tuner myself and cannot/will not comment on tuners tuning capability however I can't recommend himself or anyone else on our workshop page enough. He gave us a go when many others wouldn't, spend hours doing training with us and has given our software the time it requires to learn it.

Kabayo · May 8, 2024

Kabayo · May 8, 2024

All this stuff people tell you to get. Not everyone is related to Musk.

Rolls · May 9, 2024

Kabayo said:
All this stuff people tell you to get. Not everyone is related to Musk.

That is why we have produced a reference design and sent it to anyone who is a registered member. There are hundreds of ways the kit can be built, and also 15 different vehicle types it supports, as such the kit needs to be designed for the vehicle in question.

Also tuning a flex fuel car requires a PCMTEC tuner, we recommend you contact your tuner and ask them to contact us for support regarding a kit. There are several people building them and many shops do their own in house (as shipping is expensive).

sms2022 · May 9, 2024

Kabayo said:
All this stuff people tell you to get. Not everyone is related to Musk.

You saying it’s too expensive or too technologically confusing?

It is fairly expensive but these cars aren’t cheap and if you’re going to tune it might as well go all out imo. If you don’t want a tune like this there’s plenty of cheaper options that still work great, just require more monitoring and adjusting on your end which I didn’t want.

If you’re saying it’s too complex, I disagree it’s actually pretty easy to do. You’re welcome to shoot me a pm if you’re confused about one of the steps and I can walk you through it.

Rolls · Jul 18, 2024

FYI we have an updated Rev 7 guide whihc. If you contact support we can send it to you.

This guide doesn't include the requirement of setting the ECA-2 CAN ID which is required for it to function. There are two IDs depending on which vehicle you are using.

sms2022 · Jul 18, 2024

Rolls said:
FYI we have an updated Rev 7 guide whihc. If you contact support we can send it to you.

This guide doesn't include the requirement of setting the ECA-2 CAN ID which is required for it to function. There are two IDs depending on which vehicle you are using.

Correct. I didn’t want to copy your guys’ guide completely especially since I put this out on the forums publicly. That’s why I put right in there that you’ll still need the PCMTec guide. This guide really only contains my revisions to your steps in the RHD guide re: the fuel line, routing the wire into the cabin, and making the T-harness. The rest is just a basic overview so people looking at both guides understand what to reference next when going back to your guide.

sorry, probably should have made that clearer.

Nck22cordoba · Aug 21, 2024

@sms2022
Will this BOM also work for a 2022 Mach1?
I have been gaining more and more interest on getting my Mach1 a tune and flirting with the idea of going E85.

sms2022 · Aug 21, 2024

Nck22cordoba said:
@sms2022
Will this BOM also work for a 2022 Mach1?
I have been gaining more and more interest on getting my Mach1 a tune and flirting with the idea of going E85.

It should. The engines are the same besides the intake and factory tune and you’re not touching the intake and the tune is irrelevant obviously. I haven’t tested it though as I don’t have a mach 1. As long as your fuel line comes out by the firewall and connects in the same spot to the intake you should be good. I have a picture showing my hookup.

Rolls · Aug 21, 2024

You may have to wire in post SDLC (eg to the BCM or somewhere else post the OBD connector for the CAN input) other than that that vehicle is supported)