PROM, memcal, etc.

[ChrisWhewell]

So.. I got a new ecm.  Pulled the old ECM, sweating bullets out there.   The PROM says ATYH 8311 ............ arrgh.    Not on the list of true Reatta proms as far as I can tell...   geez.    I searched and searched, can't find what an 8311 is from.    Anybody know ?    Thank you

[AZVET]

Per a Google search this fits 1990 Buick Reatta, 1990 Oldsmobile Toromado.  The search led me to a GM Parts Direct web site.

Good luck brother!

[ChrisWhewell]

Thanks bro, the new ECM didn't cure my knock sensor problem, diagnostics is still gettting 5000 knocks per second and knock retard is 17 degrees, the max. I guess, next I'll try a new PROM if I can find one

[2seater]

3 hours ago, ChrisWhewell said:

Thanks bro, the new ECM didn't cure my knock sensor problem, diagnostics is still gettting 5000 knocks per second and knock retard is 17 degrees, the max. I guess, next I'll try a new PROM if I can find one

I am pretty sure the knock sensing is in the Prom. If memory serves, I got a spare Prom from Jim Finn.

[Ronnie]

This may sound a little off the wall but... if I was troubleshooting your problem I would take a good knock sensor and connect it to the wiring harness without screwing it into the engine. Then wrap it in a shop towel and lay it somewhere (away from the engine if possible) to isolate it from vibrations. Drive the car and watch the knock counts. If the knock count returns to normal the problem is in the engine. If the knock count is still 5000 the problem is the PROM or possibly a bad connection between the sensor and the ECM

[padgett]

Sounds more like either a bad sensor or a rattle in the engine. Agree try a second sensor but make sure something is screwed into the hole in the block before driving.

 

ps have made the count increment by hitting the valve cover with the butt of a screwdriver.

 

pps 8311 is the last four of the part number and can be displayed in the diagnostics as the PROM ID. However my ATYH bin has an ID of 8064.

Edited August 21, 2018 by padgett (see edit history)

[Ronnie]

If you try what I suggested above you might need to ground the body of the sensor with a jumper wire for it to work.

[ChrisWhewell]

Thanks ya'all, yeah I tried the isolate the knock sensor early on, doesn't make a difference. Also doesnt matter if its grounded or not, its an AC signal. Also tried running it disconnected. I only get 4 degrees of KR that way instead of 17. However, the 043 code will occur when its disconnected, so apparently the wire from the knock sensor to the computer is not discontinuous. I appear to be at the very last step in the FSM for code 043, where it says "Replace Mem-Cal" :( The knock sensor is brand new. I even tested the old one, it tested good but I replaced it anyway Thanks for all the helpful suggestions

Edited August 21, 2018 by ChrisWhewell (see edit history)

[ChrisWhewell]

This is out of hand, I've tried everything in the book, FSM says "replace memcal", yet I write to two long-time chip burners and they reply memcals rarely go bad. Can't seem to find any memcals, after all the time I put in to this car, its frustrating after 3 years it still has bugs. A carburetor and an HEI ignition system is sounding like a good option perhaps. The knock counts are constantly 9999, but sometimes drop to 5xxx. The motor at idle is quiet, and at idle there's no load, its inconceivable there is a single knock event happening. New sensor, new ECM, all voltages check out right on the code 043 page. Yet there is no 043 code set. I'm thinking, maybe to ditch this car, I have better things to waste my time on. Here's the real meaning of the 9999 perhaps https://numerologist.com/numerology/keep-seeing-9999

[ChrisWhewell]

Here's one reply I received Chris, the bad news is I don’t have any OEM Reatta mem-cals to sell you. But the good news is you don’t need one… Let me explain. The knock module circuit boards on these mem-cals are configured to work with a specific type of engine, regardless of what car that engine came in. However, the EPROM chip on these mem-cals contains programming specific to your Reatta. I have a way of loading the correct stock programming your Reatta needs onto a custom tuned chip AND I can supply you with a replacement mem-cal that should have a good knock sensor module on it. Cost for me to supply you with a replacement mem-cal and an adapter with bone stock ATYH programming on it will be $155.00 + shipping. If you want me to make any custom changes to the stock ATYH programming, add $55 to the above price quote. Shipping to a USA address starts at $8.00. That being said, I have to inform you that knock modules RARELY go bad on these mem-cals. So it is very likely you still have another problem causing your issues. And suspecting that, I cannot offer any guarantees what I sell you is going to fix your issue and I cannot offer you a full refund if it doesn’t – even if you return all parts I sell you to me.

[padgett]

What you need is to do a proper diagnosis and not just throw parts at it. Do you know Barney Eaton in Georgetown, he can probably offer a comparison.

 

ps back when doing proms I always changed the fans ON themperature to 185 LO and 190 HI with a 180F Stant Superstat.

[ChrisWhewell]

Thanks, I'm cooled off a bit now. There's quite a few NOS memcals available for 1990 LN3 engines with autotrans, I'll get one and pop it in.

[2seater]

43 minutes ago, ChrisWhewell said:

Thanks, I'm cooled off a bit now. There's quite a few NOS memcals available for 1990 LN3 engines with autotrans, I'll get one and pop it in.

I hope one of them works for you. I just checked to see if I have a spare Memcal but the two I have that are physically unmodified carry different programming from Ryan at GM Tuners and I don't have the proper header to reprogram one yet. Just for reference, my early '90, used an ANWU Memcal, vin xx145, so I believe others may work except for small tweaks that were done during the production run? The ANWU was labeled on the outside of the ECM case.

[ChrisWhewell]

I picked up a 16165848 for $31 off ebay. Literature source I saw, said it was from an 89 LN3 motor with an automatic trans. Its alleged to be new old stock. We'll see if it works, I can't think of any reason why it shouldn't. There's like 1000 different gm part numbers for LN3 modules, I can't imagine any of them are really all that different.

[padgett]

Differences are usually year, model, axle ratio/speedo, and Federal vs California. Many are very similar but part number sounds later. Think the BCM handles the dash display.

Edited August 26, 2018 by padgett (see edit history)

[ChrisWhewell]

yes ! Axle ratio on new chip is F17 (2.84), stock chip is F79 (2.97). So, I imagine, if it matters, the speedo might be off, or else it will shift later by a slight amount. Maybe this will be a poor man's performance upgrade, I never liked it shifting so soon anyway. I wonder how much of a difference it will make, if at all.......

Edited August 26, 2018 by ChrisWhewell (see edit history)

[Ronnie]

 It won't make any difference in shifting. The '90 transmission shift points aren't controlled by the ECM. It might make a slight difference in when the torque converter locks up.

[2seater]

Pretty sure the odometer is in the BCM but there are two items in the Memcal that appear to affect the speedometer. One is a pulse per mile setting which doesn't seem to be adjustable but there is also a pulse divider for the display and that seems to be adjustable to accurize the speedometer. There might be some inaccuracy of the speedo if the tire size for the donor car was substantially different. 

[DAVES89]

kdirk should be here for this. He would know.

[ChrisWhewell]

It should be a good learning experience anyhow. I saw on some camaro and pontiac forums, similar topic discussed. It was alleged that the same memcal was used on vehicles having differing axle ratios, and was asserted that it makes no difference. Allegedly the chip I'm getting fits the following: 1989-1991 Electra / LeSabre; 1990 Olds 98; 1989, 1991 Olds 88; 1989-1991 Bonneville. All with the LN3. Supposedly it'll be here Friday next.

[ChrisWhewell]

It would be nice if it makes the TC lock up later. All I want in the world right now is to feel the raw power of the LN3 unleashed, when the timing isn't retarded 17 degrees !! I promise to not hotrod around. lol

Edited August 27, 2018 by ChrisWhewell (see edit history)

[2seater]

1 hour ago, ChrisWhewell said:

It would be nice if it makes the TC lock up later. All I want in the world right now is to feel the raw power of the LN3 unleashed, when the timing isn't retarded 17 degrees !! I promise to not hotrod around. lol

That is definitely adjustable in the chip. I set mine to only lockup if above 55mph but expect a small mileage penalty. Once upon a time I had a lockup delay cable from JC Whitney I believe?. It installed between the plug and socket on the transmission. It prevented lockup unless in 4th gear, or about 50 mph, but I gave it away some time ago. I have a diagram I made of the circuitry somewhere and will post if interested.

[ChrisWhewell]

UPdate. I put the NOS memcal from a Lesabre with an LN3, into the Reatta. Started right up, idle is very smooth, smoother than with stock Reatta memcal. But... rpm gauge and eng. temp. gauge do not work. Also, if you remember my posts from 2 years back, when the rpm gauge isn't working, the AC won't kick on, so I have no AC. Also, in diagnostic mode, the engine data won't display. So, I took it for a spin. It definitely has noticeably much much more power. Therefore, it appears from seat of the pants that the knock retard of -17 degrees I was experiencing with the stock memcal, has been remedied by the new memcal. Wow, what a difference. Too bad no AC. Here is a riddle: "What's rarer than a 1990 Reatta ?" Answer: a good memcal for a 1990 Reatta. I found this interesting entry, concerning hard starts and memcals, unrelated to my issue but apparently there were a lot of memcals with problems. https://workshop-manuals.com/buick/reatta/v6-231_3.8l_vin_c_sfi/powertrain_management/computers_and_control_systems/memory_calibration_unit/component_information/technical_service_bulletins/customer_interest/906e8/

[DAVES89]

Go to www.car-part.com and look for a junk yard and get  a ECM from a 1990 Reatta.

[padgett]

I sent copies of all of my .bins to Sinister, have you asked them. Should have a stock  one. ATYH is the basis you want. Moates.net has adapters.

[ChrisWhewell]

Thank you. I'm beginning to wonder two things: 1) where on memcal is the diagnostics info for Reatta stored, is it on the eeprom, or the other chip ? 2) Same for the knock retard circuit, is that in the eeprom or the other chip ? Question 3, what I call the "other chip" that's not the eeprom, are they the same for all memcals ? What I'm suggesting is, a fourth question of whether re-programming the eeprom will solve my retarded knock retard problem i was having with the stock memcal. Knock counts were 5000-9999. If I knew absolutely that an eeprom re-program job would solve that, I'd do it in a minute, regrettably, I lack knowledge about the "other chip" in the memcal...

[2seater]

52 minutes ago, ChrisWhewell said:

Thank you. I'm beginning to wonder two things: 1) where on memcal is the diagnostics info for Reatta stored, is it on the eeprom, or the other chip ? 2) Same for the knock retard circuit, is that in the eeprom or the other chip ? Question 3, what I call the "other chip" that's not the eeprom, are they the same for all memcals ? What I'm suggesting is, a fourth question of whether re-programming the eeprom will solve my retarded knock retard problem i was having with the stock memcal. Knock counts were 5000-9999. If I knew absolutely that an eeprom re-program job would solve that, I'd do it in a minute, regrettably, I lack knowledge about the "other chip" in the memcal...

I am guessing the "other chip" referred to is the conventional 256k chip embedded in the larger circuit board inside the blue housing? Hopefully Padgett can better define this, but the reprogrammable part is indeed the smaller chip. I do not think the small chip does any of the storage, at least I have never found it. It is primarily the instructions on what to do with information that comes into the ECM. I know the attack and recovery instructions for knock are contained on the small chip, but I do not know if wiping and reprogramming the chip will fix a problem or not? As Padgett suggested, contacting Ryan at Sinister Performance/GM Tuners may be able to help. He has been very helpful to me in the past. My first "performance" Memcals were done by Ed Wright at Superchips, and later Ryan helped me extensively with reprogramming for my original turbocharging experiments. He did several chips for me, and finally modified a Memcal to hold a ZIF socket in place of the 256k chip so cheap and readily available chips could be programmed and easily changed.  

[ChrisWhewell]

Thanks. That's the thing.... if the problem with the knock signal processing is on the small chip, then reprogramming the EEPROM won't fix that. I've already had the ECM in and out of this car 5 times, I am a professional ECM swapper at this stage, a position which I hope I can fire myself from soon. :)

[2seater]

3 hours ago, ChrisWhewell said:

Thanks. That's the thing.... if the problem with the knock signal processing is on the small chip, then reprogramming the EEPROM won't fix that. I've already had the ECM in and out of this car 5 times, I am a professional ECM swapper at this stage, a position which I hope I can fire myself from soon.

The small chip is the only part of the larger Memcal/EEPROM that does get reprogrammed. I don't know all the details of what resides on the rest of the assembly but I know some of it is the base operating systems such as the limp home mode and open loop operation. I do not know for certain if knock processing is all done on the small chip, just that there are parameters that can be adjusted that affect it, but usually that is left alone as the factory settings work well. I am not versed well enough in this field to know all the details. I will see if I can find any better info. to illustrate what I mean.

[2seater]

I can't seem to get anything else to work, nor can I post a .pdf, so I suggest going to the TunerCat site: http://tunercat.com/

 

On the left side, scroll down to the "ECM Definition Files", click on that. When the files come up, scroll down to the Buick/Olds/Pontiac cars and $5B2 definition file. Click on the Info button on the right side. This is the list of what is contained on the 256k chip embedded in the Memcal. Many, but not all, parameters can be modified. Hope this helps. It's all free open source information. Too bad the BCM isn't the same?

 

 

[ChrisWhewell]

Thanks. I retrieved the file. thanks thanks thanks !! I'm calling the chip that is removeable, the EEPROM, and the other one that's not removeable, the smaller chip. Moates has a board one can removed the EEPROM from the memcal and solder his board in, which makes swapping EEPROMS easy. Maybe I have my terminology confused. I'm thinking of the two "chips" that make up the memcal, one is more removable than the other, and the removable one is what gets programmed, and the other one doesnt.

Edited September 1, 2018 by ChrisWhewell (see edit history)

[KDirk]

OK. Gonna throw in on this. First, the memcal contains two components within the carrier. First is a 27C256 UVEpsom, soldered to the contacts in the carrier. Removal of this IC is difficult and it best, if reporgramming one, to remove the UV block sticker and use a UV eraser chamber and then reprogram. This IC contains all the operating code for the cars engine. 

 

The second component is a dual inline  package circuit board with some surface mount components on it that serves as backup logic for limp home mode in the even of a EPROM failure. This part stores nothing, and there is nothing to reprogram. I honestly don't know what, if any, effect it would have on normal operation if the backup logic failed but the EPROM was still good. 

 

All that said, have you already replaced the ECM? I have seen ECMS that exhibit failures on only one input/output port while remaining normally functional otherwise. I had the happen on one of my 88's where the O2 sensor already read open, and was the ECM , rather than the sensor or wiring.

 

 If you have the correct MEM-CAL for the year and model, there shouldn't be issues like you are having excepting a ECM or MEM-CAL defect. And just to clear up one detail, this is a 90 your are working on, correct?

[ChrisWhewell]

Thanks, yes its 1990. I replaced the ECM two weeks ago. It sounds like I need to have the 27C256 reprogrammed

[KDirk]

Be forewarned with regard to reprogramming that the original EPROM may not always reliably take a new image due to age. We are now finding that some chips past the 25-30 year mark exhibit a tendency to have bytes that simply will not hold data for a new write cycle, even when properly erased (which is required before writing a new ROM image to the chip).

 

Hopefully you will not find that to be the case, but putting it out there as it is becoming a more common problem with legacy hardware like this. Anyway, if you get it re-programmed, will be interesting to see if that corrects the issues you are having. 

[ChrisWhewell]

Thank you. Yes, the age is a factor, I should probably get a new chip. , the original one probably failed due to age. Once I think about it for a while, I'll come up with a neat way to get the old chip un-soldered, and put one of those aftermarket ZIF boards in. At least the car is driveable, and its going to start to get cooler outside, so not having AC won't be as much of a concern. Thanks again.

[KDirk]

I've removed a few successfully by using a pair of dental picks. One to hold the carrier contact in place, a second to gently pry the IC pin and break the solder joint. I've found no good way to unsolder these so far. I have a hot air rework station and couldn't get the solder to melt temp without damaging the carrier assembly. Even with the smallest tip, using a soldering pencil to melt the joints is next to impossible. Good luck. 

[padgett]

My method is to save the original contents and code, then cut each lead and remove individually using a solder sucker. Then clean the holes with a piece of solid core wire. If have room, I replace with a ZIF socket.

[2seater]

Thanks for jumping in  As I mentioned, Ryan at Sinister/GMTuners did the zif socket for me, but while it works great for easy chip replacement, the programable part, It is too tall to let the ECM fit back into the stock location. Mine just lays on the floor while I work on the tuning aspects. If the 256k chip won't take programming, it could be replaced with a new blank replacement. I think one of Moates emulators should connect to the zif socket too to perhaps speed up tuning process?  

[2seater]

Here is a quick pic of the Memcal w/zif scket and chip installed. Please note this is a replacement ECM I purchased that came with the ATYK Memcal where my original is ANWU. I use the spare ECM to power test MAF's on the flowbench also. There may be lower profile zif's available? This one has a lever on the end to completely release the chip for removal.

 

[ChrisWhewell]

One answer is to obtain a male and female socket that matches the memcal, then, add wire between them so you effectively have an extension cord. plug the male into the ecm and mount in stock position. The female socket gets put into its own small enclosure, which can be remotely located at any desired place, like in the glovebox would be great. Then, changing memcal would be a one-minute operation. For removing eeprom from memcal, I'm thinking of a tiny flat copper bar that can contact all the pins on one side, simultaneously. Solder sucker is good, but I've also used solder blower, i.e., my compressed air nozzle. Heat the solder to melting, then pffft, blow it into oblivion. Mask off the SMT chip, and don't breathe the vapors. Otherwise, its the Padgett snip method.