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Working on an '87, automatic, 350.. We suspect a bad ecm. Does anyone know enough about those model years to help sort out options we might have in finding a replacement? The part# seems to be used in other vehicles as well.. I'd rather be trying to negotiate for an S-10 part than one for a 30 year old Corvette. Any help would be greatly appreciated!
A correct ECM 1227165 does fit an S10 but only '87 - '89 2.5E Engines so that decision wouldn't work for negotiations. A 2.5E is quite rare. Anyone selling the 1227165 probably knows what fits. The 1227165 has many newer replacement numbers. It also was used for several F bodied GM. It fit maybe a single year Cavalier also, an '86 2.0P w/manual trans I think. If you need one you need one.
Searching for another ecm has been challenging. It seems they are available.. for a price. Unfortunately, no one is willing to say whether there is a way to tell if it's the ecm or the chip that needs replacing.. and the chip is as expensive as the ecm. I'm really surprised that there isn't someone out there with the right tools and background to start an ecm supply business. With all of the cars running around with computers these days, certainly there would be need of such a service? There MUST be a way to examine the working states of an ecm to attempt to identify failed functions although I suspect it would be further complicated by the need to have the mem-cal installed which might also be suspect.. Please forgive my prattling away here.. This is wayy beyond my abilities here and I'm pressing the grey matter pretty hard right now. Thanks to all that've commented.. If I can resolve this, you folks will be the first to know!
I'm in Las Vegas.. We are simply guessing that it's the ecm that's needing attention at this point. The diagnostic code 12 that a healthy ecm is supposed to display when you ground out the diagnostic circuit on the ALDL connector is not happening plus, I have been told the owners son spent time trying to "get around" the VATS system and so this seems to be a reasonable assumption. The ecm we have is a 1227165 unit and we are looking for a replacement.. Finding one with a mem-cal would be pure BONUS! What do you need me to do?
Is there any advantage to finding one of these "newer replacement numbers"? I'm assuming that we would need the associated mem-cal as well then? Thanks for your comments.. We appreciate the help!
Is there any advantage to finding one of these "newer replacement numbers"? I'm assuming that we would need the associated mem-cal as well then? Thanks for your comments.. We appreciate the help!
Is yours in the car presently? If it's out there should be information on the PROM/mem-cal that can identify what you have. If you wanted to actually replace the PROM/mem-cal then it should match the car options. Yours is '87, A4 with what rear axle ratio?
This looks like the procedure we used out of the shop manual to diagnose the problem. We have a scanner, OTC model 3211 that works with OBD1 but it wouldn't connect with the vehicle so we went to the diagnostic procedures to find out why. We located the "No ALDL" chart and it directed us to "chart 2" when we did not have a "code 12" function. We have a steady "Service Engine Soon" light whenever the key is turned to the ON position, but there is no flashing code 12 as there would be if the diagnostic terminal on the ALDL connector were shorted (intentionally or not). We pulled the ecm, the "Service Engine Soon" light went out and the diagnostic circuit was verified to be operating correctly (not OPEN or SHORTED).AT THIS POINT, the car will start up and run but, it is literally DROWNING in fuel and runs like it is only firing on 6 or 7 cylinders. We have replaced the majority of the sensors at this point (tps, IAC, MAF..etc), new plugs and wires.. all without making much of a difference in the way the engine was running. We went through the diagnostic chart procedures as new ideas about the problem came along but in spite of the result we received, we still had the problem with the ALDL connector not working and that missing "code 12". HISTORY.. Prior to our purchase of the car, the previous owner attempted to get the car started but wasn't able to get any further than it would allow with a VATS system with a bad module. After seeing that we weren't going to find another VATS module, we installed a VATS bypass purchased off the web and the starting issue was resolved. (At this point the scanner WOULD connect and displayed a "rich condition" code. The O2 sensors were replaced but, nothing changed. The engine is being FLOODED with fuel and new regulator and injectors did not change that. NOW.. The engine starts and runs, but just barely.. The scanner will not connect to the car, and everything we have tried seems to point to the ecm but, that is mostly just our "best guess" now. Once again, Thanks to ALL of you for your interest in this! My money says it's the ecm.. It's literally ALL that's left!!
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Did you continue? It is going to ask you to verify the wiring between the ALDL and the ECM. Did you inspect the ALDL to see if the pins are spread to far apart ? Did you check ground to see if it is good. I believe the ECM ground is G104 on the block above the oil filter near the drivers side downpipe / O2 sensor. You grounded pin A at the ECM ??
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Yes to all you've asked.. We inspected the ALDL and the ecm connector for anything loose or irregular. The ground verified good. We have followed the diagnostic instructions a couple times to make sure we aren't missing something but, the code 12 display isn't happening. I purchased the scanner to work on this car when we encountered the extreme rich issue. It seemed to work initially displaying both fault codes and real time data if you started the car. Presently it will not connect. I have checked it on my own car to verify there wasn't something wrong with the scanner.
My memcal looks to be the same, I have an 87 automatic. Just checking one simple thing. With key on engine off, when you short pin A to pin B on the ALDL does anything happen, fans come on or any clicking ??
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Last edited by Vets-Vet; Mar 13, 2024 at 08:20 AM.
Ok.. key on, then apply short to A and B.. Fan comes on and there's a relay that clicks.. possibly the egr switching..
Ok.. Key OFF.. nothing happens.. no buzz, whirr or clicking at all.. Sorry for the confusion, the clinic has me fasting today.
CRAP! Just read it again.. Looks like I had it right the first time! Not a good day to be taking my word on things folks.. Question everything I claim and fer gawd sake do not loan me money! Hahahahah!!
Last edited by Ed Shaw; Mar 13, 2024 at 04:13 PM.
Reason: Misunderstood directions..
Ok so what is the car doing to where you think it needs a new ECM? Most of the components used in that ECM are obsolete which is the issue with rebuilding them. I am working on a solution for it but it will not be available for at least a year. I can also program the prom if need be but I am interested in what is wrong with the car first that led to this diagnosis.
Justin
Ok so what is the car doing to where you think it needs a new ECM? Most of the components used in that ECM are obsolete which is the issue with rebuilding them. I am working on a solution for it but it will not be available for at least a year. I can also program the prom if need be but I am interested in what is wrong with the car first that led to this diagnosis.
Justin
Hi Justin.. In a nutshell, the car is literally POURING fuel into the engine. We have replaced the injectors, fuel sending assembly, pressure regulator. plugs, wires, TPS, IAC.. ad nauseum, ad infinitum.. What clued us in to the ecm possibly being the issue was the lack of the "code 12" that is supposed to happen when you short pins A&B on the diagnostic connector. We followed the guidance provided in the shop manual for "No ADSL Code 12" and the subsequent chart that led us to and everything points towards the ecm being an issue. It's beginning to look like the problem comes and goes as we originally used an OTC model 3211 scanner (does OBD 1&2) and successfully accessed the ecm. That has since stopped connecting and here we are. Any advice you might have about all this is greatly appreciated!
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Anyone knowledgeable about 86-89 ecm's?
