Using the GM flex fuel sensor on an Fbody
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Joined: Aug 2005
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Well just so everyone knows zeitronix make an ECA that has the same output as a mg sensor for cheap and comes with a display that list E% as well. I may try to tee the output into my pcm and see if I can make it all work
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So I am very new to the tuning, I have the 411 pcm in my fbody and I already have a inline ethanol content analyzer hooked up. If I wire it into the right pin in my pcm and upload the OS from a Tahoe/suburban with hp tuner could I switch everything to get full functionality without having to relpin anything else? I'm still DBC and I do have a/c but only use a 1bar MAP
So I am very new to the tuning, I have the 411 pcm in my fbody and I already have a inline ethanol content analyzer hooked up. If I wire it into the right pin in my pcm and upload the OS from a Tahoe/suburban with hp tuner could I switch everything to get full functionality without having to relpin anything else? I'm still DBC and I do have a/c but only use a 1bar MAP
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You mean blue 56? What I'm going to try is pinning the sensor, loading the OS and switching the ac to analog(which I understand to be the f-body setting). That being said I assume the pcm would expect the signals the way the a/c is already wired and I would not have to re-pin?
You mean blue 56? What I'm going to try is pinning the sensor, loading the OS and switching the ac to analog(which I understand to be the f-body setting). That being said I assume the pcm would expect the signals the way the a/c is already wired and I would not have to re-pin?
The easiest way to do this on a Fbody is to use a P59 (blue/green) PCM and flash a 2004 GTO OS to it. There are a few pins that have to be swapped and some codes that need turned off in the GTO PCM to make everything work correctly but I have done this on a few setups now with success.
Flex fuel pin is blue connector 56 on the P59 controllers. The P01 controllers (blue/red) is on blue pin 71. There is only one operating system in 2002 on a v8 controller that had flex enabled and had the code to operate it. Unfortunately that operating system has no upgrades for 2-3bar etc so you are stuck using the OEM tune to dial things in. This is why the P59 PCM swap is ideal to make this all work. You need to make sure the P59 controller you purchase has IAC drivers built in. Most all of your express van and V6 PCM's will have the necessary drivers to operate a cable throttle correctly.
Flex fuel pin is blue connector 56 on the P59 controllers. The P01 controllers (blue/red) is on blue pin 71. There is only one operating system in 2002 on a v8 controller that had flex enabled and had the code to operate it. Unfortunately that operating system has no upgrades for 2-3bar etc so you are stuck using the OEM tune to dial things in. This is why the P59 PCM swap is ideal to make this all work. You need to make sure the P59 controller you purchase has IAC drivers built in. Most all of your express van and V6 PCM's will have the necessary drivers to operate a cable throttle correctly.
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Joined: May 2011
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From: Michigan
So is there any way to do this while remaining emissions legal? Would the VIN need to match in order to pass normal emissions testing?
The easiest way to do this on a Fbody is to use a P59 (blue/green) PCM and flash a 2004 GTO OS to it. There are a few pins that have to be swapped and some codes that need turned off in the GTO PCM to make everything work correctly but I have done this on a few setups now with success.
Flex fuel pin is blue connector 56 on the P59 controllers. The P01 controllers (blue/red) is on blue pin 71. There is only one operating system in 2002 on a v8 controller that had flex enabled and had the code to operate it. Unfortunately that operating system has no upgrades for 2-3bar etc so you are stuck using the OEM tune to dial things in. This is why the P59 PCM swap is ideal to make this all work. You need to make sure the P59 controller you purchase has IAC drivers built in. Most all of your express van and V6 PCM's will have the necessary drivers to operate a cable throttle correctly.
Flex fuel pin is blue connector 56 on the P59 controllers. The P01 controllers (blue/red) is on blue pin 71. There is only one operating system in 2002 on a v8 controller that had flex enabled and had the code to operate it. Unfortunately that operating system has no upgrades for 2-3bar etc so you are stuck using the OEM tune to dial things in. This is why the P59 PCM swap is ideal to make this all work. You need to make sure the P59 controller you purchase has IAC drivers built in. Most all of your express van and V6 PCM's will have the necessary drivers to operate a cable throttle correctly.
Thanks for the info! If you get time, you should seriously do a writeup, it'll spread like wildfire man
I don't believe there's a rate. I believe the Flex Fuel modifier table is multiplied by the measured alcohol percentage, and then added to the main spark advance table. The % doesn't change much/often...should only change with a new tank of fuel, so I don't see any need for a rate of change control either...just apply the correction as the % changes.
Last edited by Mike454SS; Oct 6, 2014 at 03:08 PM.
Can anyone who has completed the swap verify they are getting the amount of timing, in the flex fuel adder table, actually added to total timing? I successfully added the sensor to a 2006 silverado and the commanded stoich is changing and the scanner pid "alcohol content" is reading 80% alcohol but the total timing has never budged from 16. Which is what is in the high octane table and what this truck has always ran. We have the bottom row of the "flex fuel" adder table populated with 3. Seems we should be seeing 19 degrees of timing.
Can anyone who has completed the swap verify they are getting the amount of timing, in the flex fuel adder table, actually added to total timing? I successfully added the sensor to a 2006 silverado and the commanded stoich is changing and the scanner pid "alcohol content" is reading 80% alcohol but the total timing has never budged from 16. Which is what is in the high octane table and what this truck has always ran. We have the bottom row of the "flex fuel" adder table populated with 3. Seems we should be seeing 19 degrees of timing.
I ask because an 06 Silverado does not use a flex fuel sensor. It's based off 02 Sensor feedback.