Hacking/tuning the jeep ecm

[JeepsAndGuns]

So I have done some google work and constantly come up empty handed. My daily driver is a 93 jeep wrangler 4.0 straight 6. It has the factory sequencial multiport injection. With all the fun I have been having tuning the gm system I put in my cherokee, I would love to be able to tune the system in my wrangler. I know there would be much improvement with a mostly stock engine. But in the future I plan on building it into a stroker. For those who dont know about it. Its where you take the crank and rods from the older 258 straight 6 and put it in the 4.0 block and use the 4.0 pistions and you get around 4.6-4.7L out of it. Very popular thing to do with these engines. I plan on doing it once this one wears out. The normal thing people do is just swap for bigger injectors to compensate for the extra displacement. But I figure there is so much more that could be done because the engine is now pretty far from stock.

The jeep ecm is a underhood weathertight one. I have a extra one and I pulled the cover off and can see through the plastic/gel stuff and see the board and what appears to be the EPROM. The gel seems easy to dig out. If I dig it out and desoder it, what are the chances I would be able to read it with my autoprom and the tunerpro prom I/O and save it to a file? Then, finding someone to write a tunerpro defination file for it?
I'm thinking the ecm being weatherproof is the reason no one has tried to do this before. And I am not asking for someone to write a defination for free. I would be fully willing to pay for this. I would also need a datastream defination too. If these could be made, then I could simply soder in the moates adapter that allows remote mounting of the eeprom, and run a cable to under the dash and mount the eeprom there. Probably make a small box to put it in. I would then reseal the underhood ecm.
The jeep system actually uses lots of real simmilar sensors and even a couple are GM (such as the map sensor, its the exact same one on the chevy tbi systems) It has a 3 wire tps, 4 wire iac, has a cts, iat, cam and crank sensors. I think if I could find someone smart enough and willing, it could be done. Looking at all the many many definations on tunerpros website, I dont see why it couldnt.

What say yall.

[EagleMark]

I think it would be easier to repin what you have to a GM weatherproof under hood ECM. Then tune it...

[JeepsAndGuns]

About the only gm ecm/pcm I think I would swap to, would be the 1220411. Its sequencial, has great aftermarket support, and can run a 6cyl. But its just so freaking expensive to tune. It would also require harness mods, and probably a couple diffrent sensors, and a crank trigger wheel/pickup fabed for it, cause the jeep one would not work. It would be really hard to hack up the factory untouched harness in my jeep (that I have had for a long time, and has always been my baby) If I modded the stock ecm, then thats the only thing modded. If it didnt work, or work out, I could just swap back to the original ecm and be done.

So lets "pretend", for now, swapping to a diffrent ecm/pcm is not a option. I would like to keep the discussion on "is it possiable" I pulled the top cover back off the spare ecm I have, and looked through the gel with a flashlight, and its a 27c256 eprom in it, with the little picture of texas on it, also has a sticker covering the window and a bunch of numbers on it. There is a setting in the moates prom I/O for that chip. So I'm thinking it could be read? The jeep ecm's also have a 7 diget number on them, with the last 3 being twice the size of the first 4. The spare one I have is from a 93 cherokee automatic (my wrangler is a 93 5 speed) I had read the cherokee is supposed to have a "better" timing table. All I noticed was slightly less torque, so I swapped back to my original one.
The first 4 digets are the same on both, so I would assume this would translate into a ecm service number (if we want to think of it like that) and the last 3 digets are whats diffrent. So I would assume thats gonna translate into a BCC or the tune on the chip.

I just want to make sure, that beyond any reasonable doubt, that the jeep ecm is absoultely postatively not hackable/tuneable before I even start to think of swapping to a diffrent/gm pcm. I dont mind chip bruning, and I just LOVE emulation/real time tuning. And emulation is just so expensive to do with the 411.

[cmaje72]

I looked into this a couple years ago when I thought a mopar 5.2 or 5.9 swap might be good into my cherokee. I did not come up with anything except that you needed special hardware to program the PCM's and startup costs were in the $3000 range. So basically unless you were doing it on a shop level where the hardware and software would pay for itself its not DIY friendly. I did not find anyone disassembling the chips either...

[EagleMark]

That's going to be a major project. Since it's such a popular vehicle if it were possable I think it would have been done. What are guys doing when they build an engine for that vehicle?

There's an easier way to make changes to ECM for what's needed to tune the engine after you build it. PiggyBack tuners. They get wired into existing harness and make changes needed in signals to tune the new engine. I have used the Perfect Power products for vehicles such as yours with great results.
http://www.perfectpower.com/index.php?option=com_content&view=article&id=5&Itemid=7

[JeepsAndGuns]

I bet anything it has been done, but like said by cmaje72, its probably been on a shop level where they make/have lots of money and hire someone fulltime to do nothing but hack/tune the ecm.
My guess why it hasnt been done on a wider scale is because it (appears to be) a eprom based ecm, not flash based. The eprom is sodered to the motherboard and then its all encased into the waterproof gel. Its not like the gm computers where you simply take two screws out and can uber easaly remove the chip, read, hack, tune, and reinstall it. I think thats why it has been done so much and easaly on the gm ecm's. And the ford the same way, so many out there, I'm sure the mustang builders pretty much demanded a way to tune the ford computers. So a way was found. The jeep ecm on the other hand is gonna take a little more work to get to the chip. I would have no problem doing this, I however am nowhere near smart enough to read the code and do all that magic to where it can be displayed in a tunerpro format where I can understand it.

Anyone have a lead on any other forums I could join, or people to email to get in touch with someone smart enough to do said work?

[EagleMark]

I'm telling you the piggy back tuners are what guys use in cases like this. I have personally used several from Perfect Power. They will do everything we do here with GM stuff. They also work with all the GM ECMs instead of doing the chips. They also have capabilities for tuning nitrous, turbo and superchargers. Once you find out how much they cost and the ease of installation and use compared to re-inventing the wheel you will believe me.

But if anyone would know if your Jeep ECM could be done would be Westers Garage.
http://westersgarage.eidnet.org/index2.html

As far as someone to hire to disassemble a chip, write an XDF and ADX look for Traxion or Cal Editor on:
http://www.monodax.com/forums/forums.php

[1project2many]

Imagine you want to get more power from an engine but you have no idea how it works. You don't have books, you don't have the 'net, and you don't have someone else to ask. You don't know what a cam is, you've never heard of compression ratio, and the word piston has never been spoken near you. You have some tools but they may or may not fit the engine and they may or may not work together to disassemble the engine. You know someone somewhere has modified their engine so you have faith it can be done, but you have no idea what it took them to do it. All you know is if someone did their engine, then they or you should be able to modify yours. Doesn't seem like an easy job, does it?

Making a definition file and coming up with a disassembly is a huge undertaking. Around 2001 Lyndon Wester actually hired a guy to work full time on disassembling GM code for him because it takes so much effort and time to get it done. And that's with a known processor and known examples of code from similar computers. Working with an unknown ecm can take even longer. If it were simply a matter fo finding someone and handing over cash, everything would have been hacked a long time ago. What stops these efforts is the sheer time it takes to work out the details.

You can probably read the eprom in your ecm. But what you'll get won't look like anything you recognize. Will it be code? Or calibration data? Or both? You'll need to pass it throught a disassembler to know that. And in order to know what disassembler to use you'll want to know the type of processor used in the ecm. And then the disassembler may choke multiple times forcing you to make manual modifications and restart the process.

If the ecm is a chrysler design similar to some of the cars and trucks there are a few places to go. Like the GM stuff, you'd better be prepared to do some research first.
http://www.omniglht.com/cal.html
http://www.omniglht.com/sbec.html
http://www.turbo-mopar.com/forums/forumdisplay.php?36-EFI-Tuning
http://www.turbo-mopar.com/forums/knowledge.php?title=Calibrations:LM-SMEC-SBEC-Tuning-FAQ

I wish you guys would stop thinking everything needs to be SFI. The 86-87 GN is sfi and it uses an older "C3" ecm. But the Syclone is batch fire and can do everything the GN does.

[JeepsAndGuns]

Looks like I have plenty of reading to do from all those links. Might take me a little while to get through them. But it looks more promising than all the rest of the info I have been able to find.

[cmaje72]

There appears to be more info out there but still no less spendy solutions since I last searched. Do some searched using JTEC.
More reading:
http://thespeedfreaks.net/showthread.php?4116-SCT-the-real-deal-Or-PCM-Flash
http://www.jeepsunlimited.com/forums/showthread.php?t=474337
http://dodgeram.org/tech/repair/Pcm_diags/Page1.htm

[JeepsAndGuns]

Well it looks like the ecm in my jeep is whats being called a "SBEC" ecm. Its used in lots of the same year range dodge and chrysler vehicles. Seems like the dodge ones have been hacked some and people can and do read the chips, make changes, and burn new chips. But the software appears to be nothing like tunerpro. I havent even found any good info about what tuning software they are using. But I'm still searching and reading.



But just to keep the conversation going, incase tuning the jep ecm doesnt work out, and since the 12200411 gm pcm is so expensive to tune. And since I know nothing about chevy engines and all the diffrent chevy engines. Are there any chevy obd1, tunerpro supported, sequencial multiport, V6 ecm/pcm's that might could be a possiable swap. I'm still gonna exhaust most options I can find to tune the jeep ecm, but like I said, jut to keep the conversation going and explore other options, what is there out there? Not sure if I want to learn another tuning sofware, it took me so long to learn what little I know about tunerpro, and I really like it. So if I it doesnt look like I will be able to fine anyone to make a tunerpro defination, then I may start exploring those other options.

[1project2many]

There are no Chevy engines which meet your criteria.

[dave w]

I'm often asked to tune Jeeps, but I always have to decline. For what it's worth, would the Moates.net Road Runner be an option for the DIY Jeep computer?

dave w

[EagleMark]

There's also a guy who installs a MegaSquirt board in LS1 PCM case... now that I think of it why not gut your case and install a MegaSquirt to the ECM plug! All you need then is a longer cable to reach inside the cab to hook up to the laptop.

[1project2many]

I'd use a 7730 myself. Lots to gain by switching to an ecm you can adjust.

But the Mopar stuff looks kind of neat. I found an article a while back describing the ChryCo approach to fuel and spark and I was trying to find it again. While GM took to making tables, Chrysler used functions. So they've got "ramps" for spark and for fuel based on coolant temp, rpm, iat, tps, & etc. After working with cells and specific rpm/map intersections the Dodge approach seems lacking but when you think about the VE smoothers and the way many people fill in spark and VE tables, we do the same thing.

Was a guy a long time ago who swapped a GM ecm onto a Jeep I6. Was one of the first ones I know of. I think it was Jeremy Gonyou, same guy that got a job at Ford by reverse engineering GM code. :) Can't find any references right now but it wasn't a bad project for something done back in the dark ages.

[JeepsAndGuns]

Megasquirt looks like a very nice system and I have nothing personally aganst it. But in the back of my mind I just dont want to run a fully custom ecm. I cant help but thinking if something freak happens and the ecm get fried (bad alt, idiot hooks up booster cables wrong, many things could happen) I am now stuck with a jeep I cant drive untill I order a very expensive replacement. If I use a common junkyard sourced ecm/pcm, if something happens I could go into most any parts store or junkyard and get a replacement, I can also buy and keep a couple of spares.

Looking on tunerpro at nothing but the dowload page, I saw a couple V6 ecm's that are supported. (but didnt dl and look at the definations) Plus I dont know much about these engines either.




16196387


1FA.xdf (http://www.gearhead-efi.com/Fuel-Injection/download/bindefs/GM/1FA.xdf)


1FA.ads (http://www.gearhead-efi.com/Fuel-Injection/download/datastreams/GM/1FA.ads)


94-95 3.1L (L82) A-body (Century, etc)
ADS also spplies to W-Body







16183247
16197428


V5 ONLY -
5B.xdf (http://www.gearhead-efi.com/Fuel-Injection/download/bindefs/GM/5B_TPV5.xdf)


V5 ONLY - (http://www.gearhead-efi.com/Fuel-Injection/download/bindefs/GM/5B_TPV5.xdf)5B_V5.adx (http://www.gearhead-efi.com/Fuel-Injection/download/datastreams/GM/5B_V5.adx)


94-95 Series 1 3.8L (L27) and 94-95 Series 3.8L SC (L67)









16196401


2E.xdf (http://www.gearhead-efi.com/Fuel-Injection/download/bindefs/GM/2E.xdf)
V5 ONLY -
2E_tpv5.xdf (http://www.gearhead-efi.com/Fuel-Injection/download/bindefs/GM/2E_tpv5.xdf)


2E.ads (http://www.gearhead-efi.com/Fuel-Injection/download/datastreams/GM/2E.ads)


94-95 LQ1 3.4L V6

[cmaje72]

Well it looks like the ecm in my jeep is whats being called a "SBEC" ecm. .
Ahh I missed that its a Yj. I had TJ in my head. When I was looking for this stuff i was looking at the OBD2 ecu's.

[EagleMark]

Megasquirt looks like a very nice system and I have nothing personally aganst it. But in the back of my mind I just dont want to run a fully custom ecm. I cant help but thinking if something freak happens and the ecm get fried (bad alt, idiot hooks up booster cables wrong, many things could happen) I am now stuck with a jeep I cant drive untill I order a very expensive replacement. If I use a common junkyard sourced ecm/pcm, if something happens I could go into most any parts store or junkyard and get a replacement, I can also buy and keep a couple of spares.

Looking on tunerpro at nothing but the dowload page, I saw a couple V6 ecm's that are supported. (but didnt dl and look at the definations) Plus I dont know much about these engines either.





16196387



1FA.xdf (http://www.gearhead-efi.com/Fuel-Injection/download/bindefs/GM/1FA.xdf)



1FA.ads (http://www.gearhead-efi.com/Fuel-Injection/download/datastreams/GM/1FA.ads)



94-95 3.1L (L82) A-body (Century, etc)
ADS also spplies to W-Body









16183247
16197428



V5 ONLY -
5B.xdf (http://www.gearhead-efi.com/Fuel-Injection/download/bindefs/GM/5B_TPV5.xdf)



V5 ONLY - (http://www.gearhead-efi.com/Fuel-Injection/download/bindefs/GM/5B_TPV5.xdf)5B_V5.adx (http://www.gearhead-efi.com/Fuel-Injection/download/datastreams/GM/5B_V5.adx)



94-95 Series 1 3.8L (L27) and 94-95 Series 3.8L SC (L67)











16196401



2E.xdf (http://www.gearhead-efi.com/Fuel-Injection/download/bindefs/GM/2E.xdf)
V5 ONLY -
2E_tpv5.xdf (http://www.gearhead-efi.com/Fuel-Injection/download/bindefs/GM/2E_tpv5.xdf)



2E.ads (http://www.gearhead-efi.com/Fuel-Injection/download/datastreams/GM/2E.ads)



94-95 LQ1 3.4L V6



There's lots of choices for an GM ECM ready to go for 6 cylinder and well supported by TunerPro. Numbers go down because you want to replace/repin yours and use existing location under hood. The perfect choice is 1227727. But it is not sequential. Only one I know of that is under hood and sequential OBDI is for an LT1 16188051-16191333-$EE But it's for 8 cylinder, even if the PCM could do six cylinder building a six cylinder OptiSpark distributor would be mind boggling.

Now if you would just forget about sequential and run a batch fire ECM the answer is simple. 1227727 GM ECM used in many six cylinder under hood cars.

It made me remember a conversation with a Detroit Fuel Injection engeneer who has been working on developing EFI from it's inception for GM then Ford. Sequential FI was developed to meet EPA standards for idle and off idle. The way he described it was once an engine reaches like 1200 RPM it does not matter, injectors are firing so fast it does not make a hill of beans. More RPM and they hardly flinch at turning off, high RPM and they are just about wide open constantly. So why is SFI such a big deal?

[JeepsAndGuns]

The factory ecm is underhood, but I wouldnt ignore anoher option if it was a under dash unit. It wouldnt be much more work just to run some extra wire and mount it inside. Whats the datalog speed on that ecm? If my plan for tuning my factory one bombs, then I would want at least the same datalog speed at the 7427 I have in my cherokee, or faster.
Also, It would be nice if I could reuse as many of my factory sensors as I could. I already have a 1x cam sensor, and it look a lot like the gm ones I have seen pictured on here. Its also a speed denisity (MAP) based system. I think DIS would be a added plus, if possiable. I dont really want to swap to a older modded non FI distributor, I would want a crank triggered system. I know my factory crank trigger would not work, as the notches in the flywheel wont match up to anything gm uses. But my harmonic blalancer has a nice lip around it that would lend itself to being machined real easy.

[EagleMark]

1227727 is the same as your 97427, even the memcal looks the same. It is an underhood weather proof version of the 1227730 that looks like your 97427.

Not sure about all sensors, when I checked the 2001 to 2004 4.0L tuned port intake it looked like TPS, MAP, IAC and injectors would work. I had one for an old 258 I was going to do a 4.0L HO head on.

Never checked the Jeep distributor because I was going to do this:
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?21-Building-a-GM-EFI-Small-Cap-Distributor-for-TBI-Conversions!

If going to DIS jeep has a distributor with just a cam sensor on top, no cap...

[Alioth]

The SBEC2 in the pre-OBD2 4.0 HO also acts as a TCU and as a stone age body control module. You like your power door locks (y/n)? You have to retain it on some level, even if it does not control the engine any longer, or else rewire the entire vehicle. This means the odd 8v volt Chrysler triggering pattern needs to be retained, too, for AT vehicles. Transmission control is relatively straightforward if AT as the AW4 is the A340x in Toyota products (Supra/Taco) is whatever Volvo called their flavor of the Aisin-Warner slushbox. If push comes to shove, the AW4 is easily controlled... I don't have the link handy, but one guy on the Jeep forums set his up push button style a la Edsel. :P

B&G can tune the SBEC2, they have screenshots of Tunerpro on their website. Gut feeling says they took some of the turbo Dodge ECU knowledge, and were kicked info from one of the large tuning companies that decided not to pursue older vehicles. http://www.bgperformancepcm.com/

I'd like to tune the stock SBEC2, personally. The 411 PCM is also cool, but there's something elegant about not having to invent cam/crank pickups. MS1/MS2 is a your mileage may - and will - vary proposition.

[EagleMark]

Sure sounds like that Piggy Back tuner would take care of any engine mod tuning you need without all the other issues with tranmission and body control issues...

[JeepsAndGuns]

The SBEC2 in the pre-OBD2 4.0 HO also acts as a TCU and as a stone age body control module. You like your power door locks (y/n)? You have to retain it on some level, even if it does not control the engine any longer, or else rewire the entire vehicle. This means the odd 8v volt Chrysler triggering pattern needs to be retained, too, for AT vehicles. Transmission control is relatively straightforward if AT as the AW4 is the A340x in Toyota products (Supra/Taco) is whatever Volvo called their flavor of the Aisin-Warner slushbox. If push comes to shove, the AW4 is easily controlled... I don't have the link handy, but one guy on the Jeep forums set his up push button style a la Edsel. :P

B&G can tune the SBEC2, they have screenshots of Tunerpro on their website. Gut feeling says they took some of the turbo Dodge ECU knowledge, and were kicked info from one of the large tuning companies that decided not to pursue older vehicles. http://www.bgperformancepcm.com/

I'd like to tune the stock SBEC2, personally. The 411 PCM is also cool, but there's something elegant about not having to invent cam/crank pickups. MS1/MS2 is a your mileage may - and will - vary proposition.

This is in a soft top manual transmission jeep wrangler. It controlls nothing but the engine. :laugh:
I have forgotten one thing. It also regulates the alternator. But that wouldnt be hard to bypass, as there are kits to convert it.
I too have come upon BG preformance while googleing. I shot off a nice lengthy email to them explaining my situation, and my desires, and asked if they had any options, or knew of any. That was monday, I have had no response. I have a feeling I wont get one. Mabey I should call. :innocent2:


Eaglemark, I have one of those cam sensors from the 99 and up 4.0. I picked it up at the pull a part for cheap. The engine I got it from was stripped to the block and the cylinders got rained in. That cam sensor was about the only thing left on it that was good. I got it and the wiring pigtail. Not really sure why I got it either, but I did. Its basicly a distributor cut in half and the sensor stuck on top. The stock 91 and up 4.0 dist has nothing in it but the rotor and 1x cam sensor. I can take a couple pics of mine if you want to see it. Sometime around 94 or 95, they changed it slightly, and moved the sensors location inside the dist to where it can be replaced without removeing the dist and removing the gear and shaft from the housing.
99 is when the 4.0 went DIS. Its also when they changed the intake manifold design. The 99 and up intakes are a popular swap onto older 4.0's for a slight power boost. I have one here but have just been too lazy to swap it on and see for myself.
I looked at the 7730 on ebay and it doesnt look anything like the 7427. The plugs are on the side, the memcal is in a diffrent spot, and there is a 3rd yellow plug. What goes there? The 7727 has 4 plugs. What defanition would I want to use, I saw like 3 or 4 on tunerpros webside. Were they ever used with DIS? And also, what datalog speed are they?

And last, I stumbled across this. Seems rather interesting.....
http://www.thirdgen.org/techboard/diy-prom/616203-xdfs-tuning-ls1-pcms.html

[d0nk3y]

When I first started out in "industry", I worked for Mitsubishi on a joint project with Chrysler calibrating the Talon / Eclipse 2.0L A588 engines (circa model year 1996). We used an "Interrogator box" or "Ibox" to record data and interface with the SBEC in the cars. They wouldn't give us a PCM that was changeable "real-time" (and I cannot remember what the heck they called it, but the only external difference was one wire broke out of the ecu and it was connected to run one way and disconnected to make changes. IIRC, of course.

I used to have copies of the SBEC code and would make changes via hex editor and burning a new chip. The Ibox had two ZIF sockets - I'd put the new chip on the left and it would run the vehicle with my changes.... so there has to be a way. Give me some time, I'll check with my old coworkers to see if there is a way to do something. We were using the older SBEC controllers for sure, because the software guys on the project figured out a way to squeeze the additional OBDII code into the SBEC and saved the program millions of dollars not having to migrate to the SBECII.

[JeepsAndGuns]

Sounds nice. I am definately not having much luck on my research. But I have been kinda busy/distracted lately.
Definately keep me updated on what ya find out.
Getting the chip out wont be the problem, geting the info on the chip into a format I can understand is.

[Alioth]

I'm guessing BG never got back to you, huh?

[JeepsAndGuns]

Nope, never heard back from them. I havent called either, usally too busy during the day, and when I do have the time, I never think of it.

[JeepsAndGuns]

Taken from another thread on this site:


ALDL.ds files are available from vehicle manufactures so scan tools can be made to work.


So anyone know if one for my factory jeep ecm could be found and made to work with tunerpro? Would be nice if I could atleast scan and mabey datalog my stock ecm, just to see whats going on.

[EagleMark]

I don't think they are just out there for public, we are lucky to have the ones from GM.

But that is only data and codes what is coming out of ECM on serial data line. Not what's on chip or where/how to change it.

[JeepsAndGuns]

Yea I understand its only data coming out of the ecm, and not a way to tune. But I still think it would be nice to be able to datalog, even though I cant tune it. It might give more insight into possiable intermittent problems that can be tricky to track down. With 270K on all the original sensors (except o2 and injectors) I am just waiting for something to go out.

So if the files are not out there for public use, how were the GM ones obtained?

[rts91tsi]

So if the files are not out there for public use, how were the GM ones obtained?

I can't say much as far as how the GM files were obtained, but as far as the DSM stuff I'm into, a group of like minded folks put in a lot of work and research to disassemble the code. From reading through some old archives from Todd Day(pretty much the pioneer for DSM code hacking), I do know that he had some help from the GM community.

All of the DSM ECU code related documents and files are on the Yahoo group, and there is a Jeep group, as well as a Dodge group. Give it a shot if you haven't already. http://autos.groups.yahoo.com/group/jeep/

[EagleMark]

So if the files are not out there for public use, how were the GM ones obtained?Someone in the business of making scantools slipped us a copy? I don't know where they originated?

[EagleMark]

OBDII now that is easy cause they all must meet same standard...

http://en.wikipedia.org/wiki/OBD-II_PIDs

[JeepsAndGuns]

Well if the datastream for OBD2 is standarized, what about code, and tuning? Could you swap to a OBD2 jeep ecm and harness and have easyer tuning than the obd1?

That 99 grand cherokee I bought is OBD2, it has DIS, witch I think is cool.

[rts91tsi]

I am curious which microprocessor your ECU has. I have been searching around via Google and found that some of the SBECs used the exact same Motorola processor that the DSMs use, for which there is documentation available.

[EagleMark]

OBDII is in everthing 1996 and newer, but tuning software is very expensive and more complex, thats if the Jeep engine is covered under any of them...

These are for PIDS, the error codes, the ALDL side and they are all not identical but have standardized most paremeters for emissions, each manfacturer still has other PIDS and they can change from car to car, car to truck, auto to manual etc... and I know very little about this subject. My Scan Tool tells me anything I need to know about any OBDII car... and OBDI for that matter.

[1project2many]

So if the files are not out there for public use, how were the GM ones obtained?

Stuff leaked out or was "tossed" out the back door. The last thing to appear was the datastream defs. For a long time the only thing out there was the ecmguy hacs and maybe one or two other independently done files. Then stuff started showing up here and there which had GM written all over it. The 7749 and $58 are so well documented because someone in England got a copy of the GM variable list and made tuning software long before most of the gmecm guys were a cohesive group.


So anyone know if one for my factory jeep ecm could be found and made to work with tunerpro? Would be nice if I could atleast scan and mabey datalog my stock ecm, just to see whats going on.

One way to get an idea what's happening is to monitor the communications on the data line to / from scantool. This is how some of the early GM OBDII programming routines were worked out. Snap-on and others pay Chrysler for information from the data link so their scantools will work so it's not like it's a deep, dark secret. It's just an expensive secret.

[EagleMark]

Freind of mine whos a tech said most of the guys use this because it does everything a SnapOn does at 1/4 the money... well now it's 1/10th the money... I have it and it's amazing! Does all OBDI and OBDII, records data, cable to download and get upgrades each year. Mine came good through 2010 cars 2 years ago... I paid $100 more than what it is today...

http://www.amazon.com/AutoXray-AX7000-Diagnostic-Playback-Capability/dp/B001LJIZHO/ref=sr_1_1?ie=UTF8&qid=1324609726&sr=8-1

[1project2many]

We've got over $10k in our Snappy scantool and now the Snap-On dealer wants us to trade it on on a new model. I said "Make scantool software to use on the laptop and quit charging me for hardware that I don't like" but that took off like the proverbial lead dirigible

[EagleMark]

There's so many OBDII options for plugs and software for laptops... there's got to be one that is on a professional grade level? From what I know about the fleet you maintane it's just GM? That would be easier... EFI Live scan?

[JeepsAndGuns]

Seems like a program you can put on a laptop and then use a simple USB cable with interchangeable ends to connect to the diffrent aldl plugs would make way more sense than the seperate scantools. You would have a bigger screen, and more room to store more data, and then a simple update over the internet to keep it up to date. Could be cheaper too, as you dont have to pay for the actual scan tool unit. All you need is the cable, and the disc to load the program from. Heck, it could even be downloaded over the internet.

[JeepsAndGuns]

I am curious which microprocessor your ECU has. I have been searching around via Google and found that some of the SBECs used the exact same Motorola processor that the DSMs use, for which there is documentation available.

Not sure how I could find out. If your not having any luck finding out, I doubt I would have any luck. Would the numbers off my ecm help? Its the factory original ecm, and its a 93 wrangler 4.0 inline six, and a 5 speed manual trans.
Also, pardon my ignorance, but what is DSM?

[rts91tsi]

Not sure how I could find out. If your not having any luck finding out, I doubt I would have any luck. Would the numbers off my ecm help? Its the factory original ecm, and its a 93 wrangler 4.0 inline six, and a 5 speed manual trans.
Also, pardon my ignorance, but what is DSM?

The link I posted will show you where to look for the microprocessor, then get the numbers/letters off the top of the chip.http://starparts.chrysler.com/starlibrary/marketing/reman/Electric.pdf

I also found a Snap-On PDF, that has specific ranges for data items that may be useful to building an ADX. http://www1.snapon.com/display/DocMgmtDisplayFile.aspx?fileid=4669

Once you find those numbers, if documentation is available for the processor, it should contain a listing of the opcodes necessary for operation and execution of the eprom's bin. Then the real fun begins! :idea:
De-solder the EPROM, figure out the offset for the chip being used, read and upload the chips contents to a file on the computer. Depending on how much information you want to find out, there is a program called Binutils, that should be able to help if you want to disassemble the code. http://www.gnu.org/software/binutils/

DSM is an acronym for Diamond Star Motors, the collaboration between Chrysler and Mitsubishi, which is mostly associated with Eagle Talons, Plymouth Lasers, and Mitsubishi Eclipses. These cars were produced at a factory in Normal, IL and technically an American made car.

[EagleMark]

Then if you can figure it out? I read on TGO that a guy is commenting a disassembled code and he is up to 20,000 lines and about half done! He new were most things were. TunerPro software is 40,000 lines of code I read somewhere Mark has into it...

I have over 100 hours into making an adx for LT1 and half the code was written by TunerPro, I just entered parameter information, it's only 2000 lines... and I had the address of where things were.

Cracking GM code was done as a project at Ohio State University way back when by genius type computer geeks who knew microprocessor languages and took a team and years to get it done... luckily all the rest of GM code was similar so we have hacks for most...

I commend you for even thinking about doing this and the conversation is great! I am enjoying it... but even if you had the info you are talking about years of work... but you are getting closer and may find a way! :thumbsup:

[hexdmy]

My specialty is calibrating the SBEC2 and JTEC engine controllers, like the one used on your Jeep. A couple of pointers ,

- Chrysler ecus use a special serial communication routine that runs at 7812.5 and 62500 baud .

- TunerPro will work for the 3D tables (yes SBEC2 ecus use 3D tables) and constants, but will not work for the functions, as Chrysler uses a 16 bit slope value between breakpoints.

- You can connect a Moates Ostrich to the ecu and emulate as long as your ecu is not using a latched chip.

[EagleMark]

So it can be done?

I just looked through TunerPro and each value in xdf (bin side) and adx (data acqusistion side) had 8, 16 and 32 bit options. Does that make it doable?

[hexdmy]

TunerPro cannot adjust the functions used in the SBEC ecu. You would need to use software like DCAL .

[1project2many]

De-solder the EPROM, figure out the offset for the chip being used, read and upload the chips contents to a file on the computer.&

Do the DSM ecu's EPROMs contain executable code? Early GM ecm's placed code on a separate PROM while the removeable EPROM contained primarily calibration data which made things much tougher in the beginning.


Cracking GM code was done as a project at Ohio State University way back when by genius type computer geeks who knew microprocessor languages and took a team and years to get it done... luckily all the rest of GM code was similar so we have hacks for most...

I uderstand the point behind this but I want to set this straight. The only connection to OSU was that the DIY_EFI mailing list was hosted there when enough like minded guys were on the list to get the project started. Most of the guys in the project were not computer geeks who knew microprocessor language. And for all intents and purposes, if the effort resembled a team it was only very loosely so. There were a couple of guys who had some really kewl skills and had done exceptional things working out their own disassemblies. There were some engineers and electronics techs and few guys who had experience with network administration. But there were also plenty of guys who were into cars and had a little advanced skill with automotive systems and believed they could get the GM code figured out. We kludged around in the beginning working out data locations and functions for a very limited amount of stuff. Every now and then someone would find a tidbit or a piece of software that gave a good clue. But the real advancements came when "Ecmguy" decided to reward the efforts being made by releasing a few of his hacs to the public. Without that, the entire effort would probably have fizzled. After that, more and more previously unknown data started coming to light, most of it from outside the group that started the project. What's important is this:

You didn't have to be a genius to make tuning a possibility, but you had to be willing to put in effort and it did require some outside help.

If you could learn how an engine worked chances were you could learn enough to work with code.

You had to pay attention to detail and you had to be veeery patient. Many hours can be burned up with very little apparent progress.

There are some quality hacs around from unexpected sources:

An Avionics tech for a DOD facility. This guy told me he made it a point to spend 20 - 30 hrs per week working on disassembly. He had great access to Motorola documentation, much of which described example circuits and code which exactly matched GM circuits and code.

A Surgeon who taught himself Motorola machine opcodes and used previously existing hacs to do a few uncommon masks such as a turbocharged lotus and a ZR1. He found it relaxing.

A dentist and a network admin who spent a bunch of time working out code for the 7749 / $58. I believe they were the first to release a 3 bar calibration for the SyTy world.

An Apple computer guru. He liked Fieros and got curious abuut what was in his car's ecm.

An engineering student who wrote some interesting papers because he was curious about how the ECM code actually worked.

It would be unfair to believe you couldn't do this because it takes some god-like ability or talent. But it does take time, dedication, help, and desire.

/soapbox

[JeepsAndGuns]

My specialty is calibrating the SBEC2 and JTEC engine controllers, like the one used on your Jeep. A couple of pointers ,

- Chrysler ecus use a special serial communication routine that runs at 7812.5 and 62500 baud .

- TunerPro will work for the 3D tables (yes SBEC2 ecus use 3D tables) and constants, but will not work for the functions, as Chrysler uses a 16 bit slope value between breakpoints.

- You can connect a Moates Ostrich to the ecu and emulate as long as your ecu is not using a latched chip.

So can I use the moates autoprom to read the EPROM? And for that much, if you can use the ostrich to emulate, I'm guessing I could also use the autoprom?
If so, do you know what offsets I need to use to read the chip. I can get the chip out, and probably read it, but as far as actually cracking the code and writing definations is over my head. Thats why I am willing to pay someone to do it.

I am currently visiting family for the holidays, so once I get back I will get the numbers/letters off the microprocessor.

[JeepsAndGuns]

TunerPro cannot adjust the functions used in the SBEC ecu. You would need to use software like DCAL .

Still learning. What is ment by functions?

[1project2many]

Thats why I am willing to pay someone to do it.
You probably do not make enough to pay someone to do this work. It takes a lot of time.


Still learning. What is ment by functions?
Math. Mopar systems used math equations instead of lookup tables in some areas. You would need to edit the equation instead of tables full of data.

[JeepsAndGuns]

The link I posted will show you where to look for the microprocessor, then get the numbers/letters off the top of the chip.http://starparts.chrysler.com/starlibrary/marketing/reman/Electric.pdf


Ok, back home. I pulled the top off the spare ecm I have, and it looks a little diffrent on the inside than the one in that link, but I think I got the correct numbers.
The numbers goes as follows:

SC80571VFN
672T02
C96N
ZQESI9312

Also the eprom is a 27C256-20

[rts91tsi]

Do the DSM ecu's EPROMs contain executable code? Early GM ecm's placed code on a separate PROM while the removeable EPROM contained primarily calibration data which made things much tougher in the beginning.

Yeah, the DSM's EPROM contains executable code.

[rts91tsi]

Ok, back home. I pulled the top off the spare ecm I have, and it looks a little diffrent on the inside than the one in that link, but I think I got the correct numbers.
The numbers goes as follows:

SC80571VFN
672T02
C96N
ZQESI9312

Also the eprom is a 27C256-20

The SC80571VFN is a Motorola processor. I'm not familiar with it, but there is info out there about them.
http://www.seekchip.com/icstock-S/SC80571VFN.html
(http://www.seekchip.com/icstock-S/SC80571VFN.html)
The C96N is also a Motorola Processor which also has documentation.
http://www.alldatasheet.com/view.jsp?Searchword=MC68HC11A0P-C96N

There are also a few tools out there if you are serious about making your own hack. This IDE should work for the C96N, and has colored syntax for opcodes.
http://autos.groups.yahoo.com/group/dsm-ecu/message/8159

[shelgame]

I do a lot of stuff with the turbo Mopar ECU's. All of the SBEC's and SBECII's use a 68HC11A series processor.

I have many of the Jeep bins already and have kind of started dis-assembling the code. But, I need to get back into it. I had a '95 GC last year that I had intended to do a cal for, but just didn't get back to the code. Too busy with other projects. Anyway, the GC was too rusty for me to use as a project (I know, big shock, a rusty Jeep in Michigan). But, I'm still interested in hacking the code. I'd be happy to help as I find stuff...

[shelgame]

You probably do not make enough to pay someone to do this work. It takes a lot of time.


Math. Mopar systems used math equations instead of lookup tables in some areas. You would need to edit the equation instead of tables full of data.

I think he meant the 2D tables. Chrysler used a unique format for the 2D lookup tables. Instead of just putting in X,Y coordinates and using straight interpolation (which must calculate the slope to complete the interpolation); they actually simply encoded the pre-calculated slope into the table. Takes up twice as much storage, but probably only a tenth of the computation time. They started using that format back in '84 in the very first ECU which used a 6805(?) processor that had no divide instruction built in. So, the interpolation would have tken even longer to complete. It was just much easier to give up a little data space to save that precious computation time. Pretty ingenious if you ask me. Since it was a unique format to Chrysler, they kept it even when they went to the more powerfull 6811 (which actually can do division pretty easily).

Because they encoded the slope, TunerPro cannot fully recalculate the 2D tables when a point is moved. TunerPro isn't setup to do the slope. The only programs that do it are D-Cal, CHeM, and the newer MP Tuner.

For what it's worth, I have completely dis-assembled the turbo code back to my own source code that can compile a brand spakin' new binary.

[JeepsAndGuns]

So, basicly your saying tunerpro is not gonna work with the jeep bin files?

My jeep is a 93 wrangler 4.0L 5 speed. The spare ecm I have is actually from a 93 cherokee 4.0L auto. I dont mind opening its and removing the eprom, I just cant do that to one in my wrangler, cause I still need to drive it.
If you have experance with these, do you happen to know the diffrence between auto and manual bins? I had originally bought the cherokee ecm because I red online that they were supposed to have a "better" timing curve to them. I swapped it in and everything ran the same, the only thing I noticed was I actually lost a little torque. So I put my original back in. Would be curious to know the diffrences in the two.
But as I stated before, its all way over my head. I am at the mercy of smarter people who can hack it and get it to the point I can load it into a user friendly tunings sowfware where I can then make desired changes and burn back to a chip.

[shelgame]

So, basicly your saying tunerpro is not gonna work with the jeep bin files?

My jeep is a 93 wrangler 4.0L 5 speed. The spare ecm I have is actually from a 93 cherokee 4.0L auto. I dont mind opening its and removing the eprom, I just cant do that to one in my wrangler, cause I still need to drive it.
If you have experance with these, do you happen to know the diffrence between auto and manual bins? I had originally bought the cherokee ecm because I red online that they were supposed to have a "better" timing curve to them. I swapped it in and everything ran the same, the only thing I noticed was I actually lost a little torque. So I put my original back in. Would be curious to know the diffrences in the two.
But as I stated before, its all way over my head. I am at the mercy of smarter people who can hack it and get it to the point I can load it into a user friendly tunings sowfware where I can then make desired changes and burn back to a chip.

Uusally, the only difference between manual and auto is in the idle control. But, it's possible that the auto trans cal has a bit more timing in places. Though, not likely overall...

[JeepsAndGuns]

I guess the only way to really tell would be to actually compare the bin files. If I could get this cherokee auto trans ecm and bin file defined and tuneable, then I would purchase another wrangler manual ecm to take apart and get the chip/bin out of it so it could be hacked/defined.

[ssmacwilliams]

Have you gotten any further on your jeep obd1 project? I have a 95 wrangler 6 cyl auto,and am looking into doing the same thing. I would like to output everything out to my android tablet, but I am coming up empty as well... I have done a little development of apps for the android and have the IDE to do it, but I am running into the same problem you are. Of course it looks you like you are heads and sholders beyond my full grasp of the project... I did find something that my aide in the communicaiton between a tablet and the jeep. This guy is using bluetooth to connect to a honda.http://www.linszter.net/?lang=en http://www.linszter.net/2011/08/09/ttl-bluetooth-adapter-a-honda-datalog-programhoz/?lang=en But I believe the crux of the matter is the what you have already denoted and that is the "bin" files. I am work with databases on a daily basis and quite often I have to compare 2 database to find modifications that were done. I use some free software called Schema Compare or something like that... I am not sure it will work on a bin file, but it would hurt to give it a shot. Please keep me in the loop I would like to be involved in something like this if you are still pursuing it.

[JeepsAndGuns]

I have pretty much all but given up on the stock Jeep ECM. Its a great ecu, tough and durable, but as far as tuning support, there pretty much none. An those who can do it, will not share. This thread acted like it was gonna take off and go somewhere, but ended up smashing into a brick wall.

I have decided to instead, to convert it over to a GM 1227727 ECM. A few little mods to the engine (dist. and alt.), and hooking up the harness and I should be in business. There is way more tuning support for GM ECM's.

[sev]

I have pretty much all but given up on the stock Jeep ECM. Its a great ecu, tough and durable, but as far as tuning support, there pretty much none. An those who can do it, will not share. This thread acted like it was gonna take off and go somewhere, but ended up smashing into a brick wall.

I have decided to instead, to convert it over to a GM 1227727 ECM. A few little mods to the engine (dist. and alt.), and hooking up the harness and I should be in business. There is way more tuning support for GM ECM's.

I know this thread has been dead for 5 years, but for those interested.

There's actually been a concerted effort to tune the sbec-2 for jeeps over on turbo-mopar.com. While my knowledge is limited on engine management, Ive been giving a few of the guys over there a hand with testing/figuring out some of this stuff.

Turns out the SBEC-II in jeep is similar, though not identical to the SBEC's used in turbo chryslers and others. There's been some good progress on reverse engineering the code and finding 3d tables/parameters for OBD-1 jeeps. There exists a suite of tools called MPTune and MPScan that are written by one of the very talented guys on Turbo-Mopar that allow for datalogging and tuning of these old chrysler ECUs. The effort that was mounted was to figure out the tables for the Jeep ECUs in order to utilize MPTune to be able to write new calibrations.


Separate form this effort, I actually purchased a tune from Chris Jensen, who is known for tuning SBEC/JTEC based Vipers and such. He also does jeeps and did end up street tuning my OBD-1 jeep. Though we agreed that any effort on turbo-mopar would be separate from the tune he provided me. Aka, We made a gentlemen's agreement him I would keep the tune he sold me away from the internet and I respect that. I only bring it up to mention it is possible and has been done before by professionals.

The cool thing with these SBEC-IIs are theyre pretty cheap, plentiful and interchangeable. The later ones are flashable, but the earlier ones need to be socketed. Socketing them is pretty easy if you know how to solder and are patient. I was able to put a socket on a spare SBEC-II I had in order to have Chris tune it for me. My experience with Jeep SBEC's are they have a built in Latch chip so just a regular run of the mill 27sf256 chip will work in the socket.

I can say Chris's tune provided my stockish 4.0 with a very noticeable gain in power and drivability! So there is definitely room for improvement on the table. He did tell me that in his experience, Chrysler seemed to put a huge margin of error for timing on 4.0s and there definitely is room for improvement.

Here's the thread this stuff was happening on, it's sort of slowed down but I think there's still interest:

http://www.turbo-mopar.com/forums/showthread.php?71712-94-Jeep-Cherokee-Tuning
http://www.turbo-mopar.com/forums/showthread.php?81501-Jeep-SBEC-Flashing-Questions
http://www.turbo-mopar.com/forums/showthread.php?81173-91-95-Jeep-SBEC-tuning

[sev]

I am curious which microprocessor your ECU has. I have been searching around via Google and found that some of the SBECs used the exact same Motorola processor that the DSMs use, for which there is documentation available.

SBEC-IIs used in the jeep are 68HC11s

( I know.. 7 years later...)

[JeepsAndGuns]

Very interesting. If someone makes a complete XDF (or whatever it is called in their program) for the jeep 4.0 cal, I would be very interested. I have yet to convert mine over the the GM ecm (life has been getting in the way)

[34blazer]

Very interesting. If someone makes a complete XDF (or whatever it is called in their program) for the jeep 4.0 cal, I would be very interested. I have yet to convert mine over the the GM ecm (life has been getting in the way)

JG, working on piggybacking the JTEC in my Ram with a 7727. About 2/3 complete. Maybe ill share once its running, hopefully.

[vwnut8392]

I have done some work on the renix jeep ECU for the 4.0. i liked it because of the fact that its a true speed density ECU. my goal was to see if it was possible for it to be used in a turbo 4.0 application with larger MAP sensor and scale in larger injectors for more fuel. finding the basic timing and fueling tables was fairly easy using winOLS. i have since made basic timing and fueling adjustments to the ECU and it made a world of a difference in how it ran. in a non turbo application all you really need to work with is timing and fueling mapping to have a basic tune that will work. well just giving some info even though you was working with the later ECU thats not the bastard like the one i have as everyone calls it.

[jtwthaxj]

I have a 4.7L stroker in my 1997 XJ, during the build I knew tuning would be difficult, but I didn't realize it would be next to impossible. Sev, I have found Chris's company online and wanted to see if you thought he may tune other vehicles remotely? I found a guy a while back "flyinryan" of flyinryantuning, but by the time I contacted him he said he no longer did the remote tuning. My XJ definitely has plenty of grunt since doing the swap, but it is still kind of sluggish compared to what I was hoping for. (I know it's a toaster on wheels and lacks the aerodynamics of a Porsche, but was hoping for a little more.)

thanks!

[sev]

I have a 4.7L stroker in my 1997 XJ, during the build I knew tuning would be difficult, but I didn't realize it would be next to impossible. Sev, I have found Chris's company online and wanted to see if you thought he may tune other vehicles remotely? I found a guy a while back "flyinryan" of flyinryantuning, but by the time I contacted him he said he no longer did the remote tuning. My XJ definitely has plenty of grunt since doing the swap, but it is still kind of sluggish compared to what I was hoping for. (I know it's a toaster on wheels and lacks the aerodynamics of a Porsche, but was hoping for a little more.)

thanks!


Sorry for the late reply. I know Chris specializes in tuning J-tecs, which is the ECU your 97 cherokee uses. I am not sure if he does remote tuning, but I would wager to guess he probably would. Have you tried emailing him?

Chris@christuned.com

He's a busy guy, so it might take a little while to get back to you, but he's one of the best.

[Shawanda]

I have, and looked through the gel with a flashlight, and its a 27c256 eprom in it, with the little picture of texas on it, also has a sticker covering the window and a bunch of numbers on it. There is a setting in the moates prom I/O for that chip. So I'm thinking it could be read jeep ecm's also have a 7 diget number on them, with the last 3 being twice the size of the first 4.

[1gcrazy]

I have an ibox. No idea how to use it.