First of all, I think this one deserves a disclaimer. Ok. Here goes. proceed at your own risk. If at any point you dont feel comfortable with what your doing, please either stop while you can or let a pro take over. You may want to buy an extra ecu just in case something goes horribly wrong. The methods I use may be considered a bit risky by some, but there is always an either (a) more expensive or (b) more challanging/time consuming way to do things. I think that about covers it...
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First things first. Why would you want to do this? Its obviously a pretty chalanging task and is going to cost a little pocket-change to get going in the first place, so whats the point? Plus, wouldnt nissan want to put the best tune on their cars from the factory? Why would they give us the shaft in such a fashion? The answers? because. Altima's arent for us performance lovers. Theyre grocery getters and nissan knew it, so they are tuned for efficienty and the ability to run on the chitty 87 octane gas. Well there are a couple of cool things about reflashing your own ecu. (Even if your still na...)
First off, upgradability. If you want a more aggressive N/A tune for now, but want to go turbo later on, you have the ability without spending any more money. Just pop out your chips and rewrite em' (or use new chips if you buy the cheapo non-erasable or UV erasble crap...who does that anymore?)
Secondly, you learn alot about whats going on in your car just by working with this stuff.
Thirdly. Jimmy wolf is expensive and enthalpy isnt much better. Plus each time you upgrade your shite, you gotta pay out the ass for a re-tune. Hence the upgradability mentioned about becomes even cooler.
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What your going to need:
-A computer with a parallel port for the prom' burner. (more than likely, all the cheep burners use a parallel port atleast...)
-An ECU. I would reccomend hitting up ebay so you can be doing this and not have your car out of commision at the same time. Be sure to get an ecu with matching transmission type as your car. Some ppl say that it matters...but I dont know if I believe them.
-A daughterboard. WTF is a daughterboard? Basically its a little PCB circut that adapts 2 8-bit eprom's into a 16-bit bus, and then adapts that to a 40 pin header like plugs into your harddrive in your computer. Once you see the pictures, it will be obvious what I'm talking about. Dont worry yet. Any daughterboard that is for the s13 will work (dosent matter if its from a sr or a ka...just as long as its for an s13..) These can be baught either from
www.bikirom.com as the old-style boards,
www.plmsdevelopments.com, or just on random forums. Calum makes alot of these and DeviousKA does as well, so try ztechz forums of eccs.hybridka.com 's for sale section...
-at least 2 eeproms of size 256 or higher or their flash equilivant. Sometimes ppl sell these with the boards as a package deal, but other times you gotta find em yourself. Theyre pretty cheap tho... Also, be sure that your buying the right package. A PLCC is completely different from a DIP package, so I wouldnt buy prom'z before you get your daughterboard (or atleast decide which you are going to buy) If you arent sure what Im talking about, ask the person you get the daughterboard from whether you need to buy plcc or dip package proms. Im sure they'll know.
-low-wattage soldering iron and solder for electronics. (for obvious reasons...)
-Eeprom burner. I use the willem's enhanced you can get on ebay fromn hongkong. It's cheep and works like a champ.
-standard tuning equiptment. If you wanna tune your engine, you gotta know what's goin' on in there. wideband and a consult adapter for checking your exact timing and TP are essential. (moreon consult later) Knock sensors are nice as well...I knew I would find a use for this safc2 someday
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Until we get a big enough list of ecu roms, everyone who wants to take this on is going to have to get a consult adapter. The good news is theyre fairly inexpensive and they're REALLY good tools to have on hand anyway for anything from Tuning (which your obviously interested in) to just pulling codes from your ecu. It even gives you calculated values like TP which, as you will find, are confusing as all hell. Anywho, you can get these from the for sale forums on ztechz or eccs.hybridka.com. (those sites rock too, but theyre not frequently visited.) If your a cheapass like me, you could also just make one up yourself.
here's the parts list and the schematic can be found...oh i dont know...perhaps right
here . The choice is yours...
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Instalation!
The toolz:
Vaccum Cleaner w/ wand attachment
electrical tape
drinking straw
screwdriver (philips) (+)
solder and soldering iron (25ish watts)
patience
First of all, your going to want to unscrew the 4 phillips head screws on the top and bottom of the ecu and remove the panels that the screws were attaching to the ecu. What you have should look like this:
(Picture of header)<--coming soon
Here comes the fun part. Take your vaccum cleaner's wand attachment and tape the straw to the opening, using extra electrical tape to seal the connection. Also, add a bit of electrical tape to the tip of the straw to prevent static discharge. (If you have an anti-static wristband, put it on the vaccum wand for added protection against static) (Thanks to scarboroughdub on the bikirom forums for this technique...its effective as hell. Also thanks for the picture...I hope you dont mind that I borrowed it but if you do just let me know)
Apply the soldering iron tip to one side of the solder and the vaccum to the other and just watch it get sucked away.
[sidenote]
Just so you know, this can be done using a solder sucker or desoldering braid, but these methods are frustrating or involve buying crap that is fairly expensive. But if your uncomfortable with the vaccum method, desolder however you'd like.(electronics repair shops have the tools to do this in like 5 minutes)
Once you've got everything sucked clean (You dont need it to be immaculately clean, just so theres a pretty sizable hole in the middle) You can start soldering the 20x2 connector onto the 20x2 header! This is probably the most skill-intensive part of the install as far as soldering goes, so there is no shame in taking it to an electronic's repair place in town and payin 15 bucks to have it done perfectly and in a friggin hurry. If you wanna atleast try your hand at it before you give up, you can generally clean it up pretty well with the vaccum technique if screw up a lil.
Once your done it should look like this:
From there, you can simply "plug in" the daughterboard. And vioula! Your the proud owner of a chippable ecu!
NOTE!! Your ECU will not read from the eproms on the daughterboard untill you move a jumper (0 ohm resistor...same dif I guess) from the CJ1 to the CJ2 position and solder it down. But PLEASE dont to this untill you have dumped your original ecu'c contents using the consult cable and the camulsult software linked to in the tuning sticky.
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Burning the EPROMS!
This is where the computer with a parallel port is going to come in. Alot of newer laptops have axed the bulky parallel port, so be aware that you'll need one if you use the cheap programmers on ebay (willem enhanced

)
The software with the burner will tell you the right configuration for the little dip-switches on the burner whenever you tell it what kind of chip your writing to. Be sure to note again whether its a 28-DIP package or a 32-PLCC package type eprom for the burner software configuration.
If your daughterboard requires you to split the binary into an "odd" and an "even" file, that can be done using the RomEditor Software found in the Tuning Sticky under the file menu I believe. (Ill check later) The old-style bikiboard is an odd-even style while the plmsdevelopment's one has you burn the same .bin to both chips. (pretty sweet considering rom-editor's odd even file splitting kinda sucks...bt it works if you work with it long enough...)
Now plug your proms in and install the ecu. If you havent done so already, desolder the 0 ohm resistor from the CJ1 position and resolder in the CJ2 position so the ecu reads from the daughterboard. Take it out to your car, plug it up, and turn it on. If you did everything correct your car should run like nothing ever happened to it.
uh oh. it run like ass? if so, check all your connections with a multimeter, try reburning your eeprom's, check with a magnifying glass to make sure you didnt short anyhting on the header while soldering or anything like that. If you've done all that and are convinced that you zapped something important somewhere along the way, be thankful that you only ruined a backup ecu! (sorry tho...)
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So at this point your ecu is ready for modification to its fuel and ignition maps, rev limiter, speed limiter, open/closed cycle oporation points. The sky is the limit really. If your flowing more air than usual (ahem...turbo), then you can change your whole TP scale for improved map resolution. The tuning part of this is a WHOLE nother' big writeup (theres a pretty good sticky on this called "how your ecu thinks") , but you now have the foundation in place. So hop to! There's horsepower to be had here! And it auint too expensive either. Just takes a wee bit of time and knowledge. Enjoi guys. -David