Hi everyone,

So I have a 92 ls and it doesn't shift that well. When in drive, it skips 2nd gear and foes from 1st to 3rd. So I have to shift manually to be able to get any kind of acceleration. Once I hit 3rd gear, the RPMs stay at around 2000 and I accelerate marginally. I am pretty sure it is the ECU so I was thinking of just buying one from ebay and replacing it. Can someone confirm that it is just plug and play, I was reading and all I could find was the 1996 and up models have OBD2 which is why they need the vin reprogrammed. Since mine is 92, am I able to just buy the same ECU online and plug it in? If not, I am willing to try and solder the capacitors like on the sticky since my school has soldering machines I can use, but I would just feel more comfortable if I could just replace the ECU instead of tinkering with it.

 

Yes, plug and play. I actually have my '93 ECU in my '94. Now it has the problems my 93 had, but it runs. Whatever ECU you put in, make sure it has the same part number.

 

Thanks for the info. Also, I was reading somewhere that the TCU or TCM is supposed to control the transmission and shifting, if I am having a problem shifting, would I need to replace that? I have never heard of a TCU before which was why I was surprised I found it when I was doing some research, does the 92 ls have a tcu? I opened up the glove box and under panel and I see two boxes, I see the ECU and then there is some smaller box also, is that the TCU or PCU? I honestly have no clue what those do because I have only read about people replacing their ecu. Is the TCU or PCU have to do with anything I should be aware of?

 

Shifting problems do not necessarily mean issues with the ECU. What diagnosis have you done so far? Check to see when the fluid was last changed, as well.

In the 1990-1994 LS, the engine and transmission control modules make up the ECU. The other computer you are looking at is probably the Traction control module. See the attached diagram. Ignore the red highlight in the image.

 

I did all the fluids when I got the car, about 3 months ago. I don't have really any diagnosis because I don't know how to do it, the whole wire thing and count the red ticks is kinda confusing for me. What else could be causing the trans slippage?

 

Also, does anyone know the difference between the ebay ecus, I see some for like 17 buck and others for like 75 bucks, but both of them match my part. The only thing about the 17 buck one is it has a little thing that says "all ecus need to be reprogrammed," but I thought since mine is obd1, it doesn't have to be reprogrammed, do you think this is just a generic statement that he makes about all the ecus they sell?

 

I bought mine off E-bay and didn't have to do a thing - just plug and play. The only thing you can't tell is if it has blown caps, but you can open it and check it out yourself before you install it. I am all for having one back-up ECU that you KNOW works as it should. That way, when things go weird, you replace the ECU with your own good one, and see if anything changes. Quick and easy way to eliminate a complex and expensive problem. The second ECU came in handy more than once for me.