Help me run a flex fuel setup on a C5Z06 n/a 427

[hodge9386]

yes. the only thing different between the 04z and 04 tahoe pcm i got that had flex fuel already enabled was the fuel segments. I emailed they guy at lt1swap.com awhile back and he told me if i plan on running the factory c5 o2 sensors just leave them grounded to the car.

This is the 04 tahoe pcm i got compared to at 04 z06
segments.jpg

[hodge9386]

This is what the guy from lt1swap told me.

The PCM’s are pretty much pin compatible with exception as you noted, extra o2 sensor grounds on the 03+ blue/green pcm. The alternator field duty cycle wire also moved, but not sure if 99 vette used that wire or not. If you leave your o2 sensors that are in the 99 in place, don’t change anything, you will be fine. You don’t have to add grounds to the PCM. Those are only there IF you use o2 sensors that are PWM heater controlled.



Fan controls are in the pcm, just have to turn them on in the programming, same pin locations as the 99 pcm.



all the power, grounds, data, sensor signals are identical locations. The two pcm’s have identical low reference and 5 volt reference locations by pin#, but pinouts will show different locations….any 5 volt ref pin will work for anything needing a 5v reference…and same with the low reference pins.



There was flex fuel operating systems on the 12200411 PCM used in 2001-2002….The drive by wire on the blue/green pcm will likely require a different tac module.

[podium]

That's cool. Saves a lot of headache. Sounds like I would just have to move the alt wire to use the p59 if i keep my 01 02 sensor set up.

[hodge9386]

So it looks like there is a alternator L Terminal on red 15 and Alternator F Terminal on red 52. which one do i need to move to green 15?

[podium]

Wish I would have planned ahead and licensed a 04 Tahoe OS for my 05 silverado instead of the 05 OS avalanche I licensed. Could have saved 2 credits.

[hodge9386]

I wouldnt think they would be much different

[hodge9386]

This is what im using. Keep in mind though I havent 100% verified that flex fuel is working yet. I ordered the flex fuel kit today and when it gets in i will plug it in and see if it reads the sensor. Being that this is a pcm from a z vin tahoe and flex was enabled in the tune from the factory i dont see why it wont work.

os p59.jpg

[podium]

So it looks like there is a alternator L Terminal on red 15 and Alternator F Terminal on red 52. which one do i need to move to green 15?

Generator on is green 15. I would assume red 15.

There isn't a second alternator wire on the 04 pin out. Might have to Google the differences. I think one of the wires needs a 12 volt constant. I had to do that in a swapped car I did when the wire guy forgot to wire it in.

[podium]

I wouldnt think they would be much different

OS is different. I could have used the same OS for the truck and Vette if i did the Tahoe. Avalanche OS won't work with the vette.

[hodge9386]

the code im getting is for the f terminal

[hodge9386]

I think i need to move the wire in now green (old red) 52 to green 75.

http://www.lt1swap.com/2004vortec_pcm.htm

[LSxpwrdZ]

The segment swapped files will jack with traction control, abs, electronic throttle control and other misc things in the background that we don't have access to.

No segment swaps needed, no wiring changes needed. The o2's are pwm controlled heater grounds on the P59 however the older P01 PCM cars have the heater circuit through the fuse box so the heater circuit codes just need to be killed. I take that a step further and zero the PWM tables out for the heater circuit.

This is a stock 2004 C5Z06 M6 OS with flex fuel enabled. We do this conversion in house only currently.

2000 C5 P59 Flex Fuel.png

[podium]

The segment swapped files will jack with traction control, abs, electronic throttle control and other misc things in the background that we don't have access to.

No segment swaps needed, no wiring changes needed. The o2's are pwm controlled heater grounds on the P59 however the older P01 PCM cars have the heater circuit through the fuse box so the heater circuit codes just need to be killed. I take that a step further and zero the PWM tables out for the heater circuit.

This is a stock 2004 C5Z06 M6 OS with flex fuel enabled. We do this conversion in house only currently.

2000 C5 P59 Flex Fuel.png

What if he was to use the z06 OS and then segment swap the Tahoe fuel segment? In theory, that should work.

[LSxpwrdZ]

What if he was to use the z06 OS and then segment swap the Tahoe fuel segment? In theory, that should work.

Nope, Tahoe uses a different pedal and TAC module. That is in the engine segment where all the flex fuel stuff is as well. It will run the car but the throttle and some other functions will be "quirky". We do not have access to even 1/4 of the electronic throttle parameters either so copying the existing tables back to the stock C5 values won't help.

[hodge9386]

So basically just do a complete 04 z06 segment swap? then turn on the flex fuel with the master enable?

[podium]

Nope, Tahoe uses a different pedal and TAC module. That is in the engine segment where all the flex fuel stuff is as well. It will run the car but the throttle and some other functions will be "quirky". We do not have access to even 1/4 of the electronic throttle parameters either so copying the existing tables back to the stock C5 values won't help.

Well that sucks. Thanks for being honest about why it won't work.



Will you ever offer the flex fuel for customers that are not local?

[podium]

So basically just do a complete 04 z06 segment swap? then turn on the flex fuel with the master enable?

Even though it say it has flex fuel it doesn't. There is a ton of hidden parameters we cant see with hp tuners. The c5 os doesnt have the hidden flex fuel stuff. I thought the same thing with my 05 truck. Just wire in a sensor, turn it on and go. Doesn't work like that though and that's why I had to run a avalanche OS.

[hodge9386]

his screenshot above shows it working

[podium]

his screenshot above shows it working

He is deep into the programming of the program. He didnt do a simple segment swap.

[hodge9386]

I moved the alternator field wire from red 52 to red 75 and i do longer have the charging fault. Only fault i have left is the map fault. everything seems to be working fine, both fans work, throttle seems to be fine, o2s are switching fine, fuel trims are working, maf and map are all working fine. My flex fuel sensor will be here in a couple days so i guess we will see if the flex fuel part will work or not.