fuse pull on 2012

[tonyko1]

Originally Posted by NFERNOSS

It's there on the right side (passenger side) behind faux carpet. Can't see how it works according to schematic!

Green (B+ fuse in trunk), Red (ign fuses in underhood fuse block).

Bingo, the fuse-pull is a crock, ha! I did it myself a month or so ago and didn't notice any change. I did denote that on one of the many threads about this.

Well, what is a placebo effect worth, same with buying a lottery ticket, lot of daydreaming distractions for a buck.

[NFERNOSS]

@ stieger, yes the TSB did come out in 2009 and was specific to the 10 MY. I witnessed this firsthand when they arrived and salesmen were putting the wrong fuel in them. Had the situation not been corrected, GM would have made revisions to the original PI (wasn't really a TSB) and added any additional affected years. Would I pull the carpet? Yes, because that is the correct procedure "and" fuse to pull. Reread the PI if you have it, no mention of fuse 5 cause it doesn't do anything. 20 is pulled because there are other fuses on that line, thus they do not want any parasitic feedback from the other items.

[OmniCamaro]

[The Stig]

Originally Posted by NFERNOSS

@ stieger, yes the TSB did come out in 2009 and was specific to the 10 MY. I witnessed this firsthand when they arrived and salesmen were putting the wrong fuel in them. Had the situation not been corrected, GM would have made revisions to the original PI (wasn't really a TSB) and added any additional affected years. Would I pull the carpet? Yes, because that is the correct procedure "and" fuse to pull. Reread the PI if you have it, no mention of fuse 5 cause it doesn't do anything. 20 is pulled because there are other fuses on that line, thus they do not want any parasitic feedback from the other items.

Please post a copy of PIP4728 as I do not have a copy. I would like to see where it doesn't mention fuse #5.

Per the schematic you posted earlier it looks like (again I'm not an electrical engineer - speaking of, are you an electrical engineer? ) fuses #5 and #20 are further down/up the line than the B+ fuse. And from what I've learned on here and from YouTube videos is that if you interrupt a circuit anywhere it turns the lightbulb off (that's what we used anyway).

Also, am I reading it right that fuse #5 is the only one directly connected to the battery?

And now for my responses.

Originally Posted by TheHorse13

I decided to ask GM about the #20 and #5 fuse pull and what the effects are on the vehicle. Because this procedure is not a documented process, they would not comment on it.

I asked the question another way and this is a direct quote from GM Engineering (Via Jeff, our forum customer service guy):

There you have it folks. Interpret it any way that you like.

Originally Posted by GMRULZ

I just dynoed mine to get a baseline (600 miles) and it put down 319rwhp twice then we pulled the pcm fuses for it to forget the LTFT (Long Term Fuel Trims), engine had more heatsoak than the first two pulls and it put down 327rwhp...Let me tell you picking up 8rwhp by doing that, this computer has a serious nanny program. The trans tune alone is going to be awesome. It really woke up my A6 Vette. I put ARH headers on it the day after and as soon as the Vararam is ready that will go on and I will get it tuned. So have faith o L99 bretheren...The curious thing I`ve noted is how there is a slight sip in the graph after 5250rpm`s then it picks back up, I`m assuming this may be when the VVT kicks out and is no longer making that extra midrange power. Any tuners can explain that? I`ve seen it on other L99 graphs, but not on the LS3 graphs...

Originally Posted by Camar0wn3d

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.

[NFERNOSS]

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

Subject:Higher Than Expected 0-60 MPH (97 KPH) Acceleration Time

Models:2010 Chevrolet Camaro
with V8 Active Fuel Management Engine (RPO L99)
and 6 Speed Automatic Transmission (RPO MYC)

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
<A href="http://gsi.xw.gm.com/newsi/showDoc.do?docSyskey=2366489&from=bcpi#N65563">Condition/Concern:


Some customers may complain of higher than expected 0-60 MPH (97 KPH) acceleration times when hot ambient temperatures are present. In some cases, they may report 0-60 times around 7 seconds.
This may be the result of the vehicle being filled with regular grade unleaded gasoline at one time. If the vehicle has been filled with regular unleaded gasoline, the ECM may be compensating for the lower octane by retarding the ignition timing during certain driving conditions.
<A href="http://gsi.xw.gm.com/newsi/showDoc.do?docSyskey=2366489&from=bcpi#N65575">Recommendation/Instructions:


If SI diagnosis does not isolate the cause of this concern, perform the suggestions below if the customer wants the best performance from their Camaro:

1. In an area where it is legal to do so, take a snapshot of a 0-60 WOT acceleration event and compare the vehicle speed parameter to the snapshot timer to determine the 0-60 MPH time.
2. Determine what gasoline octane the customer has been filling the vehicle with.
• 2a. If they have never used anything but premium unleaded with a posted octane of 93 or higher, go to step 3.

• 2b. If they occasionally use regular or mid-grade gasoline, the gasoline must be removed from the tank and it must be refilled with premium fuel of 93 octane or greater. This can be done by advising the customer to switch to premium fuel of 93 octane or greater and returning after a few tanks of premium fuel have been consumed. Or, if immediate results are necessary, drain the fuel tank, refill it with premium fuel of 93 octane or greater, and drive the vehicle at least 15 miles to purge the old fuel out of the fuel rail and lines.

3. Reprogram the ECM with the latest TIS2Web calibrations to reset the ECM adapts. Normally this reset can also be accomplished by pulling the 2 main ECM fuses (F13R (F10R on 11-12 MY) and F20U) shown in the ECM Power, Ground, MIL, and Serial Data Schematic (SI Document # 2209065).
4. In an area where it is legal to do so, take another snapshot of a 0-60 WOT acceleration event and compare it to the original snapshot to determine if the 0-60 MPH time has increased. If an increase is noted, advise the customer that they should only use premium unleaded gasoline with a posted octane rating of 93 or higher to continue getting the best performance from their Camaro. This is outlined on page 8-45 of the owner's manual. GM Connect Message G_0000037144 was also sent out on 9/2/2009 about filling stock units with premium gasoline.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

[The Stig]

Originally Posted by NFERNOSS

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

Subject:Higher Than Expected 0-60 MPH (97 KPH) Acceleration Time

Models:2010 Chevrolet Camaro
with V8 Active Fuel Management Engine (RPO L99)
and 6 Speed Automatic Transmission (RPO MYC)

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
<A href="http://gsi.xw.gm.com/newsi/showDoc.do?docSyskey=2366489&from=bcpi#N65563">Condition/Concern:


Some customers may complain of higher than expected 0-60 MPH (97 KPH) acceleration times when hot ambient temperatures are present. In some cases, they may report 0-60 times around 7 seconds.
This may be the result of the vehicle being filled with regular grade unleaded gasoline at one time. If the vehicle has been filled with regular unleaded gasoline, the ECM may be compensating for the lower octane by retarding the ignition timing during certain driving conditions.
<A href="http://gsi.xw.gm.com/newsi/showDoc.do?docSyskey=2366489&from=bcpi#N65575">Recommendation/Instructions:


If SI diagnosis does not isolate the cause of this concern, perform the suggestions below if the customer wants the best performance from their Camaro:

1. In an area where it is legal to do so, take a snapshot of a 0-60 WOT acceleration event and compare the vehicle speed parameter to the snapshot timer to determine the 0-60 MPH time.
2. Determine what gasoline octane the customer has been filling the vehicle with.
• 2a. If they have never used anything but premium unleaded with a posted octane of 93 or higher, go to step 3.

• 2b. If they occasionally use regular or mid-grade gasoline, the gasoline must be removed from the tank and it must be refilled with premium fuel of 93 octane or greater. This can be done by advising the customer to switch to premium fuel of 93 octane or greater and returning after a few tanks of premium fuel have been consumed. Or, if immediate results are necessary, drain the fuel tank, refill it with premium fuel of 93 octane or greater, and drive the vehicle at least 15 miles to purge the old fuel out of the fuel rail and lines.

3. Reprogram the ECM with the latest TIS2Web calibrations to reset the ECM adapts. Normally this reset can also be accomplished by pulling the 2 main ECM fuses (F13R (F10R on 11-12 MY) and F20U) shown in the ECM Power, Ground, MIL, and Serial Data Schematic (SI Document # 2209065).
4. In an area where it is legal to do so, take another snapshot of a 0-60 WOT acceleration event and compare it to the original snapshot to determine if the 0-60 MPH time has increased. If an increase is noted, advise the customer that they should only use premium unleaded gasoline with a posted octane rating of 93 or higher to continue getting the best performance from their Camaro. This is outlined on page 8-45 of the owner's manual. GM Connect Message G_0000037144 was also sent out on 9/2/2009 about filling stock units with premium gasoline.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

So to answer the OP's question. Yes, the Fuse Pull does work on 2012 camaros. Thank you for posting the PIP NFERNOSS.

[NFERNOSS]

Now, am I an electrical engineer? No, a 32 year GM Tech, which means I repair engineer mistakes in my employers eyes. I specialize in electrical repair and do 99% of the Corvette work here, which includes the classics (I have a '66' 427 Convertible sitting in one of my stalls as we speak).

The first piece of info is correct. There are no octane (or fuel) tables. It uses spark timing tables to adjust for the variance in octane. Seeing no spark knock from the sensors "should" allow the ECM to go back to the High Octane table.

The piece with the dyno graph. The author doesn't know what he is talking about. There is no VVT on the L99's. Only displacement on demand (DOD), which any L99 owner will attest only comes into play during certain cruising situations and coastdown for the most part. My '09' 4WD is Procharged and I have it turned off, makes no difference in fuel mileage.

The last piece which mentions the LS1. That PCM uses a completely different system. There are only two fuses, one for battery supply, the other is ignition to turn on the PCM. Here again, I owned at one time a 2004 GTO with the LS1 that was running a Maggie with meth injection and nitrous. I know the system well, as I spent many hours with my HP Tuners program messing with it. It's two octane tables were set identical so as not to go into a low performance issue (some with tunes have commented about this here already).

If you look at my schematic, the F10RA fuse supplies constant battery voltage to the ECM. The F20UA fuse is powered up by the "Ignition Run Relay" which the BCM switches on being the Power Mode Master. The F5UA fuse then gets power along with other fuses on that circuit for other items when the ECM closes a ground within itself to power up the Engine Controls Ignition Relay, this also totally powers up the ECM.

[NFERNOSS]

Originally Posted by stieger

So to answer the OP's question. Yes, the Fuse Pull does work on 2012 camaros. Thank you for posting the PIP NFERNOSS.

I added the 11-12 MY part, it is not part of the PI. Did it only to show the fuse designation differences between years.

[The Stig]

Originally Posted by NFERNOSS

Now, am I an electrical engineer? No, a 32 year GM Tech, which means I repair engineer mistakes in my employers eyes. I specialize in electrical repair and do 99% of the Corvette work here, which includes the classics (I have a '66' 427 Convertible sitting in one of my stalls as we speak).

The first piece of info is correct. There are no octane (or fuel) tables. It uses spark timing tables to adjust for the variance in octane. Seeing no spark knock from the sensors "should" allow the ECM to go back to the High Octane table.

The piece with the dyno graph. The author doesn't know what he is talking about. There is no VVT on the L99's. Only displacement on demand (DOD), which any L99 owner will attest only comes into play during certain cruising situations and coastdown for the most part. My '09' 4WD is Procharged and I have it turned off, makes no difference in fuel mileage.

The last piece which mentions the LS1. That PCM uses a completely different system. There are only two fuses, one for battery supply, the other is ignition to turn on the PCM. Here again, I owned at one time a 2004 GTO with the LS1 that was running a Maggie with meth injection and nitrous. I know the system well, as I spent many hours with my HP Tuners program messing with it. It's two octane tables were set identical so as not to go into a low performance issue (some with tunes have commented about this here already).

If you look at my schematic, the F10RA fuse supplies constant battery voltage to the ECM. The F20UA fuse is powered up by the "Ignition Run Relay" which the BCM switches on being the Power Mode Master. The F5UA fuse then gets power along with other fuses on that circuit for other items when the ECM closes a ground within itself to power up the Engine Controls Ignition Relay, this also totally powers up the ECM.

Huh.

Guess its all in our heads then.

[PQ]

NFERNOSS, is there a reason that you come in here acting like a total douche bag from the go? Did we, somehow, offend you with this.

You are obviously more 'in the know' and 'qualified' than we are. We are not GM techs. Only a bunch of guys trying to figure out why our cars were driving .8 seconds too slow consistantly. Placeabo my ass. I have dyno sheets and videos and timed runs to back up my claim. AND the engineers who came down here to Alabama to drive one of our cars. (before you audited and graded their work of course)

Two GM engineers came down HERE to Alabama DROVE a car with the problem. AND acknowledged the problem and set it right before they left. It was only then that we figured out the fuse pull. It is WELL documented how and why we used those fuses. If the info or one of the fuses didn't need to be in the equation then it's certainly NOT our fault for not knowing and assuming it was necessary since the fuse pull OBVIOUSLY instantly gave my car that .8 second on THE FIRST RUN after a hundred runs prior.

But nevermind those engineers. You are apparently the guy who engineers AFTER the engineers.

So tell me Professor, what deduction were we supposed to make? We tried and tried to get someone who knew these systems in here to explain. But to no avail. But now we have YOU.

So instead of acting like a dickhead, how about laying out for us is a less sarcastic, smartassed way?

You can't deny that our cars were 'fixed' using the fuse pull. If you do could you please tell us the basis of your denial, given our success using it?

We've been waiting for you actually. We'd like to know what the deal really is.

If it's placeabo then how did my car record a quarter mile .8 seconds faster in average and litteraly .5 seconds faster (on the VERY FIRST run, after the fuse pull) than the fastest time I recorded in over a hundred runs?

Again, we'd love to make this as accurate as we can, and get to the bottom of it once and for all, IF you can do it without the condecending way that you come off.

[NFERNOSS]

Douche and dickhead......lol.......WOW! I've been called an a$$hole before, but never those names.
I am trying to figure this out as well, as to why those two fuses, which schematically do not remove power from the ECM, are claiming to work for you guys (and gals). Not trying to be condescending, stieger and I were having a lively conversation I thought. Even the PI from 2009 for the 2010's clearly does not mention the 5 fuse under the hood, it points out the B+ fuse in the trunk. I myself am trying to understand how it is possible this is working.

[PQ]

Originally Posted by NFERNOSS

Douche and dickhead......lol.......WOW! I've been called an a$$hole before, but never those names.
I am trying to figure this out as well, as to why those two fuses, which schematically do not remove power from the ECM, are claiming to work for you guys (and gals). Not trying to be condescending, stieger and I were having a lively conversation I thought. Even the PI from 2009 for the 2010's clearly does not mention the 5 fuse under the hood, it points out the B+ fuse in the trunk. I myself am trying to understand how it is possible this is working.

I strategically said 'Acting Like'............

This way I'm not outside of forum rules.

All we know is what I just posted. We got the idea after the engineers left Bama and Scotts car was running lights out and mine was still posting 14 second quarter mile and 6.2 second 0-60s.

When the engineers left they never told Scott what they did. Only that they found the issue. I should say HIS issue) Scott saw the thread where the tuner pulled those two threads before he tuned GMRULZ's car to 'Get the ecm to factory defaults'.

I had already done a battery disconnect for the night, and before and after dynos........... no difference and tried fuel boost and several other small things to no avail.

Scott called me that August 2009 Sunday morning and I refused to pull the fuses figuring it was a big waste of time. He talked me into it and I did it. No harm. Well when I put them back in 3 hours or so later after he called me back, I went immediately out to run the car on the clock and video. It sounded better on start up. And when I ran it I recorded a 5.2 second 0-60. I thought it was a mistake. (but the way my car felt and sounded I figured it was accurate) Me previous best singe run recorded 5.7 and was a cool and dry morning. I did a few more runs and all were under 5.3 seconds 0-60. So about 5 runs ALL better than the fastest run I had made in the 2 months prior to that and all WELL faster than my Average of around 6.2 seconds. I even recorded a run of 4.9 seconds. Which was .8 fast than the fastest pre-fuse pull.

As far as the next two MYs, I asked the few people I know at GM and they confirmed that they had no new info but that it more than likely hadn't been addressed on the assembly line. That coupled with the claims that we were getting.

Were some of those placeabo? I suppose it's possible. But I had moved on with my mods anyway so wasn't in a place to have any first hand knowledge.

I have asked guys ALL THE WHILE since to time their cars and document it the way I did. Nobody has done it. Not my fault but leaves questions for sure.

I do not know how to read electrical schematics. I did not find what we figured to be a battery back-up in line from the battery to ECM. Not sure why the battery disconnect didn't help me the first time.

I do know that I have dyno sheets showing my first pull being rich as hell and pulling 297 RWHP as apposed to running a healthy mixture and 335 after the fuse pull.

I have asked ANYONE who could explain it better to help out and have had a few try but nobody has come in here to explain it without first telling us we were imagining our gains.

Makes me laugh me ass off when someone comes in and says "This is BS, I pulled mine and nothing happened".

People misunderstand what we are saying. The fuse pull was NEVER said to be able to ADD power to a healthy SS. Just to adjust a nannied condition in one that was affected by low octane gas.

[MYDLIFECRISIS]

I did the fuse pull and my car "woke up". I'm not an engineer, but I did stay at a Holiday Inn Express last night.

[tonyko1]

Sorry guys, and gals, the schematics if correct, and I do trust they are more so than any anecdotal evidence stated here suggests.................pulling those fuses does NOTHING.