Switch to E85 in 01 gmc 1500

[jheiner]

Im a bit new to HPtuners and tuning. No i wont be really tuning but i want to switch over to E85 and i have most the items ( pump injectors sensor tank etc ). My worry is how do i wire the flex sensor into the ecm ( p01 ) and activate it. Can i do this with the ecm i have? Would i need to write a different OS into the ECM and then i would be able to make this happen? I pulled the tune details from previous tuner and am basing everything off of that. TIAInitial tune 6.2.2022.hpt

[5FDP]

Pretty sure the only OS that supports E85 is from a 2002 Tahoe, so you'd have to change that before anything.

[dhoagland]

Pretty sure the only OS that supports E85 is from a 2002 Tahoe, so you'd have to change that before anything.

So for understanding....

It would be best to Flash Via SPS with a correct VIN that supported flex fueling and tune from there (the posted tune seems to have 2 bar OS applied)...

This is better than finding a Tune in the repository (which I did, and it claims to be a fresh SPS flash) and writing entire.
Because writing entire still leaves out 2 segments that could cause issues.

[2xLS1]

So for understanding....

It would be best to Flash Via SPS with a correct VIN that supported flex fueling and tune from there (the posted tune seems to have 2 bar OS applied)...

This is better than finding a Tune in the repository (which I did, and it claims to be a fresh SPS flash) and writing entire.
Because writing entire still leaves out 2 segments that could cause issues.

That does not apply to P01 and P59 PCMs

[Matt Vardaman]

I got a stock file for a 2002 Tahoe with the OS 12216125. I transferred my tune data (MAF curve, VE table, PE, Trans, etc) I bought two more credits to Flash the OS to my 2001 Silverado 5.3. I wired the Flex fuel sensor to the pcm and plumbed it on the feed line. You have to Disable Vats before you do a Write Entire. If done correctly it works just fine. I'm running an AEM 340lph Ethanol/methanol pump with the 50lb/hr flex injectors (part # 12613412) I ran flex fuel on the stock pump and injectors for a week or two without any trouble before I upgraded the fuel system, but that's not recommended because the injector would run out well before 4500rpm on a mild cammed 5.3.

[dhoagland]

That does not apply to P01 and P59 PCMs

Thank You!

[jheiner]

I got a stock file for a 2002 Tahoe with the OS 12216125. I transferred my tune data (MAF curve, VE table, PE, Trans, etc) I bought two more credits to Flash the OS to my 2001 Silverado 5.3. I wired the Flex fuel sensor to the pcm and plumbed it on the feed line. You have to Disable Vats before you do a Write Entire. If done correctly it works just fine. I'm running an AEM 340lph Ethanol/methanol pump with the 50lb/hr flex injectors (part # 12613412) I ran flex fuel on the stock pump and injectors for a week or two without any trouble before I upgraded the fuel system, but that's not recommended because the injector would run out well before 4500rpm on a mild cammed 5.3.

Thanks man. Just downloaded the OS 12216125 file and going to do like you said and transfer my original tune data over. ( have dual screens at work so should make it easier ). Ill have to change the trans setting from 4l60e to 80e. Do you know where you wired the flex fuel sensor into the pcm. think its three wires. 12vdc, ground, and then the signal has to go to pcm correct?

[kevin87turbot]

Thanks man. Just downloaded the OS 12216125 file and going to do like you said and transfer my original tune data over. ( have dual screens at work so should make it easier ). Ill have to change the trans setting from 4l60e to 80e. Do you know where you wired the flex fuel sensor into the pcm. think its three wires. 12vdc, ground, and then the signal has to go to pcm correct?

You'll need to do a segment swap in order to swap to a 4L80E.
The flex fuel sensor will connect to Blue 56 terminal.

[Matt Vardaman]

Thanks man. Just downloaded the OS 12216125 file and going to do like you said and transfer my original tune data over. ( have dual screens at work so should make it easier ). Ill have to change the trans setting from 4l60e to 80e. Do you know where you wired the flex fuel sensor into the pcm. think its three wires. 12vdc, ground, and then the signal has to go to pcm correct?

I'm not a fan of LS1tech but this guy did a decent write-up. https://ls1tech.com/forums/pcm-diagn...-write-up.html

I used that information, but used a less expensive and slightly smaller Gm flex content sensor (continental) and an ICT Billet pigtail.
Part#: ADO-13507128
* Item: SENSOR ASM-FLEX FUEL
* Status: Shipped on 7/27/2021
* Price: $58.99
*
* Part#: ICB-WPFLX40
* Item: WIRE SENSOR PIGTAIL
* Status: Shipped on 7/27/2021
* Price: $14.99
* Quantity: 1

[jameswis01]

Hey there. Just letting you know, I'm about to tackle this same task...
I have a 2000 Silverado, which I'm swapping to a 6.0l... I'm going to be using the newer DBW style intake which DOES NOT have the vacuum operated Fuel Pressure Regulator. I'm going to use a standalone regulator with built in return for my fuel pressure. I'm going to be running 80lb injectors and the Flex Fuel Sensor will be piped in as well.
So far, I have a 2004 Suburban as a parts truck, and I think it has a P59 ECU in it. I may use it and solder in the IAC Transistor ("69200 Singapore" is what the 15pin chip says) that way I don't need the Drive By Wire pedal, but I could go to that later if I wanted.
I'm not sure if my idea will work yet or not.
If you find a Tune that will work with the P01 and allow you to add the Flex Fuel Settings, please let me know which it is, and if it works.
If i get this working, I'll be sure to reply and let you know..
Also, It's my understanding the P59 ECU's are a bit more durable, so maybe there's a thought??? Up to you..
Keep it touch..
Thanks,
James