ECM Code Question

[handcannon]

I have a 94 K2500 "F" vin. The PO to my PO apparently towed with this truck. He put on a Turbomaster and removed the intake snorkle. I have not been able to tell if he did any other mods.

Today I did the TCC lockup mod using foncop1's underdash method. While I had the dash/glovebox apart I decided to see what the letter code was on the ECM and the tune chip.

I may be mistaken, but I have always been under the impression that these two codes were supposed to be the same. I was surprised to find they were not the same. The code on the outside of the ECM, in two places, was BKYL. When I opened the cover plate on the bottom of the ECM I found the code BPBR.

My questions are:

1) am I mistaken that the codes are supposed to be the same?

2) Could this be an aftermarket tune? I always figured somebodys aftermarket tune would sport that companies logo.

I know, I didn't need to go that deep just to do the TCC lockup mod, but that's me. I just gotta know what's down underneath or just around the next corner. I'm rather new to diesels and my curiousity is hard to keep under control.

Don

 

[ak diesel driver]

my 94 k2500 has bjax on the outside and bmsd on the inside . I believe it is all original

 

[buddy]

They would match from the factory, but there are service bulletins that replace older chips for certain issues.

In AKs case BJAX was for the DS4-5068 IP, and someone exchanged that for a DS4-5067/5521 compatable IP.

Someone may have replaced your PCM at any time to troubleshoot or whatever and transferred the original EPROM. You never know.

 

[handcannon]

Thanks ak and buddy for your replies. Obviously the truck runs good. I was apparently under a mistaken impression and now I know better.

Don

 

[buddy]

Any PCM from 94 and 95 will interchange and most EPROMs will interchange too. At least the 5 PCMs I have run in my truck from 2 94s and 3 95s all worked fine and Ive tried many EPROM programs from both years.