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- - Fuse Pull: Low Octane Fuel Fix For L99 and LS3. Reset Fuel Map for High Octane Fuel. (https://www.camaro5.com/forums/showthread.php?t=38964)

Fuse Pull: Low Octane Fuel Fix For L99 and LS3. Reset Fuel Map for High Octane Fuel.

As reported on Homepage.

Okay - after seeing a request for a sticky on how this is done, if someone can post up a couple pics' and exactly how/what to do to correct the power issue with L99s and low octane table, then I'll sticky it here. I think it can go over to the DYI Section too, however, I think it'll do more good here for now. Unless Admin'/Mods' say otherwise, I'll leave it here.

So, again, if someone can snap a few pics', so the DYI'er knows exactly what he/she's doing, and do a quick write-up, and maybe short background on why, I'll change this to a sticky and obviously give credit where it's due.

It should be understood that there is always a risk in DYI'ing, and that this site, Administrators, Moderators, and Members hold no responsibility for any conditions that may arise from performing this on your car; it is completely the responsibility of the DYI'er and owner of the car. This is not a guaranteed fix; only things that some members have shared through their own experimentation.

Waiting on some more confirmation from a member who is working with their dealer to verify the good/bad with regard to this proceedure.

UPDATE: While not officially confirmed, '10 and '11 models do not have modified calibrations to correct this issue. It does NOT appear there is a reflash to correct this. Reliable source(s) say that either a TECH II reflash or this procedure are the only ways to correct this issue. It's unknown if this will change in the future, however, if low octane is detected, the only way for the PCM to get back into the high octane table is outlined a sentence ago.

#PIP4728: Higher Than Expected 0-60 MPH (97 KPH) Acceleration Time- (Nov 4, 2009)
How about that :thumbsup::chevy:

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Some interesting reads:
http://www.camaro5.com/forums/showthread.php?t=38915
http://www.camaro5.com/forums/showthread.php?t=38838
http://www.camaro5.com/forums/showthread.php?t=38872
http://www.camaro5.com/forums/showthread.php?t=39028

Does it really work?... http://www.camaro5.com/forums/showthread.php?t=36837 There's one test...

Make sure the engine and ignition are turned off

Locate Fuse Panel in front of the passenger's side front strut tower and pull the cover

Remove #5 and #20 (15A fuses) (photo of location below)

Let the car sit for at least several hours (overnight is preferable)

Install #5 and #20 (15A) fuses

Install Fuse Panel cover

Restart vehicle and enjoy

Note: Do not unplug the battery. It has no effect.

Attachment 48815

Data collected from: Scott@Bjorn3D, CamaroSpike23, PQ, GMRULZ, tribone

Nice, we should try to dyno it and see if it does anything. :)

I have read the threads, are there any downsides to this? Our car driving for 40 mins with a hot motor right up on a dyno made 315rwhp

Nice post! I'm wondering though, is it really necessary to let it sit for hours with the fuses out? What is the reason for that? Any time I've reset stuff in my Fusion, I just pull the fuses out just to see if it's not blown, then put it back in... :iono:

Just curious if there's a reason that I may not know about :D

I'm thinking I'm gonna try this when I get my car back though!

By the way... the OP lists irpq11's thread twice. In addition, the following threads are related:

http://www.camaro5.com/forums/showthread.php?t=38872
http://www.camaro5.com/forums/showthread.php?t=39028

Just in case you want to add them to the list :thumbsup:

Here's a pic guys.

Attachment 48807

Can someone post a vid of how to take them out because I'm kind of scared lol

The white/grey grabber at the bottom right of the pic Hulk1212 is used to pull them out. Once you use that its a piece of cake to get them out.

why is this only an L99 problem? have no LS3s seen this?

Quote:

Originally Posted by Indpowr (Post 839804)

I have read the threads, are there any downsides to this? Our car driving for 40 mins with a hot motor right up on a dyno made 315rwhp

:iono: I'll certainly report it right away if my car blows up. :laugh:

Quote:

Originally Posted by DDustiNN (Post 840126)

Probably not for hours. I just wanted to make damn sure it was long enough.

Quote:

Originally Posted by matteo (Post 840322)

why is this only an L99 problem? have no LS3s seen this?

There haven't really been any LS3s reported as being really slow.

However, if you check the boards there is one claim that he benefited real good from this.

This place rocks for information!!!

Went to my dealer to get my tires sensors reset (Changed rims and tires) and told him about the fuse mod and he was amazed out how much more info is on the web and expecially in this forum than he has available to him from GM.

I gave this a try after thinking my Camaro seemed a little bit laggy to 60. Last night around 10:30 I pulled the two fuses, this morning around 6:20 I put them back in. Found a nice spot away from the city and made a 0-60 run in drive mode, both traction modes off. It was fast! Really Fast!

However, I was not happy during the night last night we had a 10 degree drop in temp. So it was around 59 this morning. Hopefully it will warm up some today and I will be able to get in another run after work.

Quote:

Originally Posted by DDustiNN (Post 840157)

Edited - thanks for pointing that out. I missed that, lol :thumbsup:

Quote:

Originally Posted by tribone (Post 840182)

Here's a pic guys.

Attachment 48807

Great pic', and thanks.

Quote:

Originally Posted by irpq11 (Post 840448)

:iono: I'll certainly report it right away if my car blows up. :laugh:

Probably not for hours. I just wanted to make damn sure it was long enough.

There haven't really been any LS3s reported as being really slow.

However, if you check the boards there is one claim that he benefited real good from this.

I'm interested in seeing if this affects the LS3 cars as much as it seems it does the L99s. I think the L99 is more dogged-down with nanny controls because of the tranny (self-preservation...) but that'd be something I'd try just in case. :iono:

Quote:

Originally Posted by wh0rsep0wer (Post 841329)

I tuned in HPTuners on my LS1 and if it is the same for an L99/LS3, this is what happens when you pull the fuses:

There are two tables values used for spark timing - high octane table and low octane table. If you use 93 octane from day one, your computer is using spark timing from the high octane table. If you got a tank of 87 from the dealer, the engine experienced premature detonation and the knock sensors went crazy, and told the computer to use the low octane timing table. What is supposed to happen is after a while of not seeing detonation from the knock sensors, the computer (ECU)tries the high octane spark timing table again. (This doesn't appear to be happening - THIS IS THE PROBLEM!!!!).

The values in the high octane and low octane tables are NON-VOLATILE MEMORY (meaning they are there even if you lose power -like when you do the fuse pull). These tables are usually adjusted when you get a custom tune, and burned into the non-volatile memory. So therefore if you get a custom tune YOU WILL NOT LOSE THESE "TUNED" VALUES with the fuse pull.

What WILL happen with the fuse pull is your volatile memory will be reset. This includes long term + short term fuel trims, knock retard, etc... but what is important in this case is the little parameter that determines which spark table to use will reset...meaning if you were running from the low octane tables before (safe + slow mode), after the fuse pull it will force the computer to try the high octane table again (super giggle fun happy rockin' mode).

However it is important to note that you shouldn't need to try the fuse pull if you've only used high octane gas since getting a custom tune, because burning the tune to the ECU resets all volatile memory. This is why it will go through the idle re-learn process and may run a little weird for the first 20 minutes or so after burning a tune or pulling the fuses.

Pulling the fuses is no different from recovering from a dead battery. The only reason I could see that it would be a problem to pull the fuses is if GM wanted to run diagnostics on the cars with the problem and needed to see the volatile values.

I thought this would be a good place for this quote. :thumbsup: