Alright, I have a 1993 GMC Suburban 3/4 ton 4x4 with a 350. I have the 4L80E trans. Since Ive had the truck, havent had Overdrive at all. Only First-3rd. Took her to the trans shop for an opinion on what the problem was, diagnostic said my ecm read my trans to be a 4L60e, but its OBVIOUSLY a 4L60E. So obviously my ECM needs to be replaced. Now my question, I wont be able to afford my brand new ECM for a few weeks, but I found a 1990-1991 chevy cheyenne (GMT400 bodystyle) its a 350, eight lug 3/4 ton with a 4L80e. Infact, the only difference between the two is my Suburban is a 93, and this pick up is somewhere between 1990-1991. Otherwise, same motor, same trans, and my suburban is 4x4 and the pick ups a 2WD. My question, can I run this ECM temporarily until I can afford the VIN matching new computer from GM. 20 bucks vs 250 bucks, Id wrather spend the 20 bucks for the used ECM, run my truck for a few weeks til I can spare the cash for the brand new. I want to run the diagnostic on my trans and find out why I dont have overdrive, though Im told that the computer not matching could very well be my issue all together, which would be great news. If someone could please respond asap, I need to know in the next two hours so I can grab that ECM, otherwise trucks going to scrap yard.

Also, Im aware theres a great possibility that the difference in years could cause my truck to be tuned different, run richer, the emissions could get screwed up, etc etc, but if my truck runs, drives, and I get all 4 gears back, i can live with that, besides, its only for two more paychecks til I can afford the cash for the brand new one. I used to drive the very truck for work, but its long been dead, ive salvaged a few other parts from it, and Im gona grab the ECM if itll suffice. So helpe me out guys! Let me know.

 

first, be sure if it's a 60 or 80 trans. 60's are 16 bolt pans, 80 are 17 bolt, typically. IF in fact it is the ecm, the 90-91 will work fine without screwing up emissions.

 

thank you for your quick response, im sure its an 80. Distinct shapes of trans pans, one look under the truck and I clearly see it was the 80, and you just made my day haha. My issue is, the ECM thats in my truck right now doesnt have the code on it, and its not in its stock location, condition or anything. The ECM Im getting i believe is the code 1227747, and ive been looking online for a list of what code was in what year. but so far, I havent found a code listed for a 93 truck/suv. only 89-91, and 94-95. nothing for 92-93. Im sure theres a code, but nothing I can find, as of yet? Anyone know what code matches 93?

 

http://cgi.ebay.com/ebaymotors/CHEVR...Q5fAccessories

http://cgi.ebay.com/ebaymotors/87-93...Q5fAccessories

 

Awesome, way to make my day Well all thats left to do is go pick it up, throw her in and see what happens. Worst case scenario, I wasted 20 bucks. So I basically drove to work and back haha. Ive tried everything, senors n all. Once I have OD back I gotta fix my linkage as well and then Im ready to roll. Thank you for your time buddy.

 

no prob. hope it works for ya!