SVT THIS

iTrader: (27)

Okay, it is a longggggggg story but I will make it as short as possible.

1998 Z28. Put in an LS2 402/L92/L76 combo. Blew the trans. Swapped in a 4L80e w/ the harness, crossmember, etc. The car was not tuned for it yet so I had switches set up to run it as a full manual. Well, the car was running like **** so I took it to the shop that did the install. They told me the guy that put in the trans messed up some wiring. So, I took it to the guy who installed the trans. brother's auto shop. He checked everything. No bad wires. Ed Wright went over there to scan the PCM to see what was wrong. The PCM was a temporary mail order tune from PCMforless. They put a lock on it. I need to get a 99 or newer PCM anyways to run the shift sequences on the 4L80e. So, I bought a 99PCM. The guy at the shop went to work and out of 80 wires that go into the 98PCM, only TWO are compatible on the 99PCM. He told me someone could plug and play to get them all crossed over but at $80 an hour it would be a ridiculous price. He told me he would not do it regardless or pay unless I could get a wiring harness.

So, is there a wiring harness out there for a 1998 PCM controlled car with a 1999 PCM in it? If so, where? If no shops make one, are there any individuals that do? The 4L80e is becoming a common swap so by now I figured someone out there has to have done it. Please poiint me in the right direction.

The car has been down since March between rearends, motors, transmissions and now computer b.s. and I am ready to get it running...Thanks a ton
Mitchell

WKMCD

iTrader: (2)

I've looked pretty hard and no one makes a harness adapter. It appears that the connector is not available. It's made into the mother board on the PCM.

You can change the pinout but it's a lot of work...

Jake@EPP

You also could find a new engine harness from a wrecked 99+ , we have a customer that went over this route, and he is planning on boost so we just scrapped the stock computer all together and shelled out for a bs3 with trans control.

formula17

iTrader: (4)

You try calling speartech?

gonbad

Look on Corvette Forum. There was a post about how to rewire the connector for a 98 to 99 PCM swap.

edcmat-l1

iTrader: (10)

Shouldnt be that big of a deal. Tell your mechanic to call me tomorrow, Mitch. I can help him with it. Repinning the PCM connectors is probably easier than swapping the harness. Even the trans connector is almost identical from the 60 to the 80. Maybe even get me a list of the codes. Swapping PCMs may or may not take care of the codes. It may have issues with the harness/car that wont be cured by replacing/upgrading the PCM. Chances are you can make your setup work with the 98 PCM. Anyways, you got my number. Feel free to burn it up. Be out of the office tomorrow from 9 til noon.

Vetal

iTrader: (3)

What tuning suite will you be using with 99+ PCM?

phildo

iTrader: (7)

I have the exact same setup as you. I 1st put in a 99 harness. Car ran but my dash would not work.( 98 has 3 plugs for the dash 99 has 2) So I removed the 99 harness and re-pinned my 98 harness to 99 specs. Everything works now but the fuel gauge. I need to change my sender to a 99 to work. Over all the swap was pretty simple. Re-pinning was not that hard. Get masking tape and lable every wire. Remove all pins and reinstall as a 99.

Vetal

iTrader: (3)

I read that you HAVE to change instrument cluster too - isn't it true?

BlackWS6LS1

iTrader: (5)

I have a 98 and plan on doing a stroker, what problems did you run into that you need a 99+ PCM?

I have a M6

bowtiguy

iTrader: (10)

speartech is converting my 2001 harness to work with my LT1 dash running an LS7 ( with 24 tooth reluctor wheel) so anything is possible. pricey at $500 but if you add up $80/hr.....it doesn't look so bad.