I am sure that everyone has heard about pulling fuse #2 to change the adaptives to get your auto transmission to shift crisper. A technician, on a Charger website, wrote an interesting article back in 2008 against this practice. It is worth a read: "Adaptive strategy: The common misconception here is that it relearns itself in a couple of trips. Adaptive strategy is simply the small changes your pcm makes to make the vehicle run efficiently due to small changes that occur in your engine. Be it gas, cai, clogged filters, whatever. You dont want the cel coming on for the smallest of things nor does your dealer. Therefore there is some give in the parameters held by the pcm. Now there are certain things that have to happen after, a fuse pull, to relearn adaptives. They dont just relearn after two trips to mickey d's. These items are outlined in the service manual but they are similar to this: a accel from 50-70 a decel from 70-60 without brake application a idle of 20 seconds or more and so on and so on. This is called a drive cycle. Now for one of us who drives to work on the interstate we may very well finish a drive cycle in as little as two trips, but lots of people never even see the interstate in their car or drive completely different than us. Some people may not make one drive cycle a month and the computer must have two of these completed cycles to have the relearn complete. The adaptives are learned constantly 24/7 key in or out of the vehicle, and the modules communicate with each other for up to 48 hours after key off. Pulling fuses when installing a CAI, will not make the system learn any faster. It constantly does these tests 24/7 due to all the changes in cars, gas , filters etc. Remember, in most R/Ts and above they're are well over 35 modules in the car. (Please don't ask me to list them) When we pull the "magic fuses" we set a lost communication code in every single module in the car. Remember this is not OBDII where all modules communicate with the pcm. This is a CAN system. Every module from heated seat to radio, to drivers door module talks with everything from abs, esp, bas, and tcm. They all communicate. Taking the radio out of your car will set a lost communication code in every module of the car including your heated seats. This is the first code seen by the Starscan and the first code diagnosed by the technician. So here's the warranty situation. You have an airbag light due to the ocd in the passenger seat needing recalibrated. However during the last week you also pulled fuses thinking it would make you super fast. You take your car in and the tech sees 35 lost communication codes and one code in the ocd for a recal being lost. What does the tech do? He has to fix the lost communication code first because no other code is valid if the module cant even keep power. He puts the Starscan away and starts looking at your battery for dying, as that's really the only reason you should have lost communication with all the modules. He checks it and its fine. He clears codes and sends you on your way. Low and behold your airbag light comes back on cause the problem never got looked at or fixed and instead of realizing it may have been your fault you come on here and write a thread about how the stupid tech cleared codes and sent you on your way. Next issue. CELs come on for a reason guys. When your check engine light comes on it doesn't mean go and pull fuses. It is a recording of what happened and the only way your vehicle can be diagnosed. Anybody that pulls fuses in order to clear the CEL (unless you know, and or are the cause of the light) is just as good as putting electric tape over the light. If your someone that gets flat tires and instead of fixing the safety hazard you just fill up your tire every morning that continue pulling the fuses and read another thread. For the rest of us, that set code is the only way of diagnosing the issue. If you pull your fuses you have killed that code and all the tech has to go off of is a lost communication code in which he's gonna once again check the battery. Also remember , when checking codes on your EVIC, these codes are only from your pcm. This is one of 35 modules on the car. If you have an airbag light or tranny problem that code is not going to show on the EVIC. This is a window to only one module. Removing fuses has no benefit whatsoever. If you have headers, and you want your code for o2 sensors deleted before you go in for service on a esp light, than please by all means get a code reader and delete the code from the pcm. No other way can you clear just certain codes. Every other way will clear all codes and or set lost communication codes in all the modules. Now the imaginary burst of power we all get in our ass-o-meter from fuse pulling: Your car has several tables. The primary being fuel. Ideal fuel is set at 0%, in a perfect world that's where your fuel would be but it can travel +- 25%. This is for many reasons. If the filter on the fuel pump starts getting clogged you don't want your car to starve of fuel , and you don't want your check engine light coming on for stupid stuff. Therefore the computer has the ability to add fuel 1-2% to compensate this issue. You get bad gas, the computer can do the same. You put on headers, intake, heads, cam, and don't touch the fuel system, the computer can compensate up to 25% before throwing the CEL. Now on Dodges, as we have a map sensor system, we tend to run rich. Dodges normally run -15% optimally, which means it takes fuel away from basic setup. We run rich because on map cars the the map/maf is the biggest input to fuel. As we all know the map sensors sit within a foot of the fuel rails but on a maf car they are more than a couple feet away. Dodges are a Mass Air Pressure car so the computer has less time to calculate the fuel table as the air is already flowing through the intake so we tend to run a little rich and the pcm cuts back until it has learned the car. On Ford/Chevy mass aif flow cars the sensor is over by the air filter so the car has more time to calculate fuel load before that air gets to the combustion chamber. those cars tend to run lean and the computer adds fuel as needed. When we go out and pull fuses our car may jump from taking 15% fuel away to 0% which means it adds a burst of fuel. this "imaginary burst of power" is made from the car dumping too much fuel than you need. Does this mean power? NO. It means a waste of fuel , waste of gas mileage, and more emissions. The primary feeling you get is from the tcm reset and the shift pressure and timing changing. Immediately the car is relearning what you wiped out and is fixing the issue. Unless you do something huge, such as blower, stroking, cam and heads, then yes pull the iod (which the manual tells you to do anytime you wont be driving the car for a few days anyway) otherwise your car may not run at first while it is relearning the adaptives as it was setup for the stock car. However, headers, cai's, catbacks will not ever even be noticed by the pcm (cai's sometime at full throttle change a/f but that's it) so don't pull fuses when you install small things as those. I've even seen a thread where someone pulled fuses after installing rockblockers. Please guys , the modules on the car are there for a reason. Safety. They aren't there to annoy you, or make your day worse. they are inputs and outputs for brakes, airbags, seat tensioners, speed control and everything. There is a right way to fix problems on the car and there is the Jerry Springer way. Please, for the cars sake, fix it right and fix it correctly. Especially if your a parent. Please don't put the safety of your car on the line for a "imaginary burst of power".
