Ecu prom problems

[3X00-Modified]

I'd start with Ebay and then move to car-part.com

[Asylum]

What is your issue?

It is very seldom the ECU actually goes bad on ODD-1 cars.

And yours is the obviously the most used one in '89.

Can't be that hard to fine one.

[woody90gtz]

I picked up a spare at a local junkyard. I think yours is a 7730 like mine which are very common.

Eric I've had one go bad on me before, it's not that uncommon. Typically the car will just die unexpectedly and fail to restart. It will crank and not light.

[Rettax3]

No, I'm with Eric (umm, Asylum Eric, that is ) on this one. They can go bad, but it is rare. It will probably start to become more common now, as they are just getting older, but typically GM's ECMs from that era are nearly bullet-proof. Meier4356, is your car equipped with the digital instruments, or analog? Digitals used a specific, unique (to my knowledge, at least) ECM, good luck finding one for sale, they are really hard to come by anymore. I'm not sure if it is just the PROM that is different, or the entire computer, but if you need the whole thing, that wouldn't matter.

[Rettax3]

That will be a problem for you then. A non-digital ECM will NOT run your digital cluster, period. Tach (and I think speedo, too) will not function without the digi-ECM, and even the temperature gauge runs data from the ECM on your car, instead of a second individual sensor in the rear cylinder-head, like the analog cars have. Fuel-senders are also different on the analog cars (three wire, instead of four), but that can be worked around by adding a ground-line, I think. I found the procedure on here before, if you need it and can't find it, let me know, I think I copied it onto my computer. What is the problem you have, or do you just want a spare?

[Cliff8928]

The items which are provided through serial data to the cluster are RPM, Voltage and Coolant temp.

I ran my 89 GT with a J-Body PROM for a while without those working… I don't think there's any difference in a digital or non digital PROM…

Either way… Any prom listed at http://calid.gm.com/ will be correct for your car.

[RobertISaar]

That will be a problem for you then. A non-digital ECM will NOT run your digital cluster, period. Tach (and I think speedo, too) will not function without the digi-ECM, and even the temperature gauge runs data from the ECM on your car, instead of a second individual sensor in the rear cylinder-head, like the analog cars have. Fuel-senders are also different on the analog cars (three wire, instead of four), but that can be worked around by adding a ground-line, I think. I found the procedure on here before, if you need it and can't find it, let me know, I think I copied it onto my computer. What is the problem you have, or do you just want a spare?

ECM isn't the cause of that. any 1227730 is identical to any other 1227730. the difference that would cause that specific issue is the wrong MEMCAL(or at least calibration) for the application.

[woody90gtz]

Annnnnnnnnd mine crapped out on me again. Good timing since it was already parked in storage for the winter. lol

[Rettax3]

That will be a problem for you then. A non-digital ECM will NOT run your digital cluster, period. Tach (and I think speedo, too) will not function without the digi-ECM, and even the temperature gauge runs data from the ECM on your car, instead of a second individual sensor in the rear cylinder-head, like the analog cars have. Fuel-senders are also different on the analog cars (three wire, instead of four), but that can be worked around by adding a ground-line, I think. I found the procedure on here before, if you need it and can't find it, let me know, I think I copied it onto my computer. What is the problem you have, or do you just want a spare?

ECM isn't the cause of that. any 1227730 is identical to any other 1227730. the difference that would cause that specific issue is the wrong MEMCAL(or at least calibration) for the application.

He is asking for a PROM, or an ECM and PROM... So he needs a digital-instrument one or his instruments will not run right, that is what I was saying. If the ECMs are otherwise the same, that is fine (for someone who doesn't need a PROM too), but the wiring to/from the ECM is different too. I don't know if the analog instrument ECMs just have unpopulated terminals for those wires or if the differences are more fundamental than that, I never bothered to check on the differences on that level, but I will take your word for it...

[RobertISaar]

if i have an example application, i could check to see if the diagrams are different.

[Rettax3]

What would you need, so far as info, to confirm the ECM pinouts? I do know that the OBD connector on the digitals runs an orange wire (serial data) both to the ECM AND the instruments, for tach signal. They also (as I already mentioned) have a wire output to the instruments for coolant temperature that the analogs don't have. I've forgotten most of the other details regarding the ECM specifically (I can tell you definitively that the connectors into the instruments themselves are totally different -even located differently- between the two versions and do not interchange at all, but that doesn't matter to an ECM issue). I own three '90 Berettas, two digital and one analog (or it was originally ). I can always pull the ECMs out and check the pinouts on them physically if absolutely needed, and I did find the digital instruments pinout diagram I have and it tells which wires go to the ECM, Haynes/Chiltons have diagrams for the analog cars, and Haynes even has a separate diagram for the digitals, but without specific pin-location data like the Chiltons provide...

[RobertISaar]

well, a target year would really be all that is necessary.... 87 and 88 2.8 should be more or less identical. i don't know if berettas had the whole MAF disable recall issue that W-bodies did for 88 model years. 89 would definitely be MAF-less but otherwise the same, 90 would probably be different from 89 for a few reasons(EGR comes to mind).

the digi dashes weren't available in 91/later, correct? so those aren't relevant unless adapting an A1 calibration with an older car.

[Rettax3]

Yes, that is all correct. For clarity:
-Digital instrumentation was available on the Berettas only in the early-gen interiors, so '90 and earlier. I have no idea about the '87s specifically though, they kind of had their own thing going on there. It was optional on GTs, GTUs, and Indys, was NOT available on GTZs and rare or non-existent on base-models, and only came with V-6 equipped cars but could be had with either manual or automatic transmission options.*
-'87 and '88 V-6 Berettas were equipped with a MAF, and it was later phased-out by a factory program update -as you've already said.
-'89 2.8 and '90 3.1 were mostly the same, EGR was different (I think the EGR change actually happened mid-year, as some '90 3.1s supposedly had the older-style EGR, but I'm not certain on that one; I just can't recall what I've actually seen and I don't totally trust rumors or "but I had a..." tales), some wire color-codes were changed, but all sensors and even fuel injectors were the same.

*I'm sure someone on here had/has a special-ordered digi-dash base, or once saw an original digi-GTZ, or whatever. Pics prove it, more or less, and I never claimed to be a 100% accurate fountain of Beretta lore -heck, I argued against the existence of a Quad Z-26, because I had read over and over again back on bstuff that it wasn't made, until it was shoved in my face that they had a small number of them in '94, so... GM loves to make exceptions to their own rules -but this is accurate to 99.9% of the million+ Berettas that got cranked-out each year. Bottom line -don't take my word for it if you know better yourself, and never trust the guy who claims to never make mistakes.

For a target-year, I would suggest going with '89, since that is what this guy is working on. I think he is going to have a hard time finding a suitable replacement, so if you can find an alternative, that would help him out.

[RobertISaar]

89 2.8 l-body ECM diagrams(appear to be the same between digital and analog):
http://imgur.com/HprQcNO,tUfpaaY,Yovhigx

89 l-body digi cluster:
http://imgur.com/AiftpEI,0gkItiH

89 l-body analog sport cluster:
http://imgur.com/OJNhplT,YYPWHNq,JGaQO6l

finding an ECM/MEMCAL combo for something so relatively uncommon isn't going to be fun. ECMs are easy to find since they were used with almost every MPFI 60V6 application for roughly 5 or 6 years, but the MEMCAL is going to be problematic..... the easiest route i could imagine would be copying a known-good calibration for this specific application.

[Asylum]

Who the hell said they built a million + a year?

They didn't even built a million in total!!!