also does anyone know why we can't get refurbished 98 PCM's what are we supposed to do if our PCM goes bad? I thought about repinning the harness for a later PCM but not until I'm ready for some big power and engine mods.

 

I don't think seat operation has anything to do with communications, but I might be mistaken. Now, locking or unlocking with the key-fob, that would indicate communications to me. But again, I'd defer to someone like Bill or 8Vette7 or one of the other guys here who actually know something about these cars. I suspect that if the PCM says there's no comms with the DCMs, there's no comms with the DCMs.

You can sometimes find them on Ebay, need to know your part number FOR CERTAIN. Mine is a 16238212. These were in 98 Corvettes as well as 98/99 F Body cars, though it's possible not all 99 Fbodies got em. I got one on Ebay a few weeks ago for $100. Maybe $111 w/shipping. It's in my car working now and it came out of a 98 Firebird. My old one after some fiddling around no longer is throwing codes, but that's on my bench, not in the car. I will definitely put it back in and re-test it before I sell it cause it might be dead. It so happens I had the same comms-to-TAC module error that you have. But, after getting the new PCM, I put the old TAC module back in and it's never given me a hint of issue since. So, don't throw away any of this stuff you buy, you might have parts you can sell later.

I also bought one out of a 97, 16232148. The car 'ran' on that one for about a month while I attempted to get it tuned, but it turned out it has a fried input circuit on the MAP sensor so it will never read the MAP correctly, thus it's basically dead. Other than that, the 16232148 probably would work just fine for your car. I was sorta able to 'tune' it, but only using 1/3 of the MAP scale, so it was not exactly a great runner that way.

 

right on thanks for the reply Ill check all my grounds again tonight and go from there and I did disconnect the 4 wire serial connector and still had the same symptoms so if I understand right from bills post that would mean the dcm and scm modules are probably not the cause of my problems. I really hope no one else ever has these issues with there car lol cheers 🍻

 

well my friend has a 98 c5 coupe and we put his computer in my car and the car was able to read my PCM and almost all of my no communication codes went away except for the SDM I still have no communication out of it but the good news is the BCM and PCM are reading. So I found my old original refurbished PCM from zip corvettes that was in my car the day it quit and put it back in and cleared my codes and now the new codes are as follows .
PCM
P0604 HC
P1518 HC
TCS
C1241 HC
C1276 HC
BCM
B0502 HC
B0507 HC
B2482 HC
SDM
No Communication

 

Well, the P0604 sounds a lot like what I went through. I had the 601, but since it went away, I want to say you have something similar. No way do I believe the Ram is bad in your PCM.

P1518 HC Tac Module... Again, I just don't believe this code. This is another one I had, with a Tac that works just fine to this day.

I just today had a problem with my car. Very similar to this. I posted in the General forum. Want a good laugh go look at that thread. I drove the car home with no issues. Go figure...

I also had the C1276 code, that went away with all the rest. Never had the C1241 but that's only for active handling cars and mine doesn't have it.

I have a suspicion you've got something drawing current at times it should not, or a ground that goes intermittent. I might be hunting for something similar soon myself. I wish I could tell you something I did which cured that problem but I can't. I replaced stuff and it worked. Then I put the old back, and that worked.