Wrangler JK Alc % and Flex Fuel Multipliers

I'm trying to tune my stock '14 Wrangler to operate Flex Fuel on gasoline and E85, and hoping someone might be able to help. So far the cal is still stock.

After 1-2 months of driving only on E85 (80% ethanol), my "Alcohol Percent" bit in the VCM scanner is still sitting at "0%" and the "Fuel Type (SAE)" bit still reads "Gas". The LTFTs are at 30-33% across the map and I'm getting "System Too Lean" error codes (P0171 and P0174). Perhaps I need to do something like the Hellcat FFV patch? But not sure if this applicable for a Wrangler PCM.

Let me give a little more detail.
1. '14 Grand Cherokees with the same 3.6L Pentastar as my JK were flex fuel from the factory, but not the Wranglers.
https://www.edmunds.com/jeep/grand-cherokee/2014/
https://www.edmunds.com/jeep/wrangler/2014/

2. However, the hpt cal file off my JK shows tables and multipliers to adjust for flex fuel operation based on alcohol % (fueling, spark, etc.). But I'm not sure how the PCM determines "Alcohol %" to be able to input it into these tables/multipliers...

3. I've compared my Wrangler hpt file to a FFV Grand Cherokee stock hpt file from the HPT repository and found small differences, but none relating to alcohol % tables or FFV multipliers (fueling, spark, etc.). So it seems the groundwork has already been laid for me to operate my JK flex fuel like the Grand Cherokees.

4. However, as mentioned, after 1-2 months of driving on 80% ethanol, the bits in the VCM scanner for Alcohol % still read "0%" and Fuel Type (SAE) still reads "Gas". So it appears my PCM is not enabling those alcohol tables or multipliers. As a result, I'm getting lean error codes.

5. Neither the FFV Grand Cherokees nor the Wranglers have wideband O2 sensors or an in-line fuel alcohol sensor. So I assume the Chrysler FFVs sense alcohol % based on the LTFT or some other calculation based method? My LTFTs across the operating map have risen to 30-33%, but my PCM still doesn't recognize the increased alcohol content.

6. It seems the only times it runs lean are when the PCM goes into Open Loop. During Closed Loop, seems I'm dittering around stoich just fine.

Questions:
1. Why doesn't my JK recognize the alcohol level if it appears the cal file has all the alcohol tables and multipliers for FFV operation? Is there a hidden bit that I need to turn on? Can HP Tuners add it to the VCM Editor? I've checked all through the hpt file, but haven't found anything to activate an "alcohol %" variable.

2. What's actually causing the lean error codes? Am I past a threshold LTFT? Is it from the O2 sensors zeroing out in OL operation? Or from the calculated AFR (from air charge and fuel mass)? Once/if I can get the Alc % and Fuel Type working, will it stop throwing Lean Error Codes and not lean out in Open Loop?

3. Do I need a Wrangler or 3.6L pentastar specific flex fuel patch? Could I use the Hellcat patch? I'm not sure how to get it and I didn't see it when I opened "OS" in the VCM Editor, as I read in one of the Hellcat FFV patch threads. (But perhaps I needed to be connected to my PCM on the vehicle?) FYI, I'm running the latest versions of VCM Editor and Scanner.

Thank you all for helping me better understand what is going on/what I need to do!

Sounds like you have a lot of work to do, first yes, you need to do the OS patch on your stock file, save then modify from there. Hellcat patch? They are not flex from the factory either so don't bother with that. Setting up flex involves a good knowledge and is very complicated task to take on. There are tables all over the tune that must all be setup for it to work. Keep in mind that your cal may not have a patch, so your option is dedicated. You are getting lean codes because it's adding so much fuel to run correctly, with PE is Open Loop so I'm surprised it hasn't blown up yet.

Blue Bee, thanks for the reply.
How do I do the "OS patch"? When I click on the "OS" tab in my VCM Editor with the stock cal file loaded, all I see is a blank window... Does this mean (like you said) my cal might not have a patch? Could you please explain?
Once I load the OS patch, what can I expect it to do?

I believe you are right, that Hellcat's are not flex from the factory. From what I understood, isn't that why they need to install the "flex fuel" patch? (I'm just trying to piece together bits and pieces from the Hellcat flex fuel patch posts I read.

The stock Wrangler tune file already has alcohol multiplier tables for things like fuel mass, spark timing, etc. And those tables are the same as the alcohol tables for the stock Grand Cherokee tune file that is flex fuel from the factory. The question I have is how to get my Wrangler's PCM to recognize the alcohol content like the PCM of the Grand Cherokee Flex Fuel would. Is there some bit that needs to be turned on?

As long as the PCM is running in closed loop mode, I can see in the O2 sensor voltages that the engine is dittering around stoich. However, the narrow band O2 sensors flat line low voltage (lean) when I am in accel/decel in open loop. So I haven't been doing much of that to not damage the engine. I suspect the lean error codes are caused by the Fuel Trim settings to keep the engine operating stoich in closed loop.

Again, thanks for any help you all can provide.

Quote:

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Originally Posted by Torqued Up

Blue Bee, thanks for the reply.
How do I do the "OS patch"? When I click on the "OS" tab in my VCM Editor with the stock cal file loaded, all I see is a blank window... Does this mean (like you said) my cal might not have a patch? Could you please explain?
Once I load the OS patch, what can I expect it to do?

I believe you are right, that Hellcat's are not flex from the factory. From what I understood, isn't that why they need to install the "flex fuel" patch? (I'm just trying to piece together bits and pieces from the Hellcat flex fuel patch posts I read.

The stock Wrangler tune file already has alcohol multiplier tables for things like fuel mass, spark timing, etc. And those tables are the same as the alcohol tables for the stock Grand Cherokee tune file that is flex fuel from the factory. The question I have is how to get my Wrangler's PCM to recognize the alcohol content like the PCM of the Grand Cherokee Flex Fuel would. Is there some bit that needs to be turned on?

As long as the PCM is running in closed loop mode, I can see in the O2 sensor voltages that the engine is dittering around stoich. However, the narrow band O2 sensors flat line low voltage (lean) when I am in accel/decel in open loop. So I haven't been doing much of that to not damage the engine. I suspect the lean error codes are caused by the Fuel Trim settings to keep the engine operating stoich in closed loop.

Again, thanks for any help you all can provide.

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Yea if it's blank then there is no patch currently for your cal. You can send in a support ticket and ask them if they will do it. All the patch does is expand axis' in the places you need like stoich so you have a E% axis basically. HPT doesn't allow you to add the breakpoints, you can with other software so your last resort would be to tune it with something else if they don't add the "patch".

If your stock file has some of the tables then it's capable it's just not all mapped out yet in your cal.

Of course in CL it's near stoich and yes the massive corrections it must make is why it's throwing a lean code, keep in mind that the % it's adding in CL is how lean it is in OL because OL doesn't get corrections.

Thanks Blue Bee. The cal file definitely has quite a few alcohol % axes already, and everything looks identical to the flex fuel Grand Cherokee. But I'm guessing the reason the alcohol % in the scanner is not active is because there is something not "turned on" or there is something missing. Hopefully HPT can help point me in the right direction. Thanks again.

Hi! Did you find a solution? I?m trying to make my own 05 300c 5.7 hemi flexfuel. Pcm is a motorola NGC 3.