PCM

[Jason63]

is the pcm the same thing as ecm? i know im stupid and shouldn't have to ask, but anyway

 

[qwomack]

Yes they are one in the same. PCM stands for Powertrain Control Module and ECM stand Electronic Control Module.

 

[Jason63]

cool thank you

 

[buddy]

And your PCM has an EPROM (aka "chip") inside of it that is removeable/replaceable. The EPROM has all the "brains" of the PCM. retail PCMs do not come with the EPROM.

The PCM is probably the first thing a dealer or mechanic tries to replace to fix issues. And it usually doesnt fix it.

94 and 95 were the only years with that type of PCM/EPROM setup. Some PCMs were used in both 94 and 95, but most part numbers are year specific. the EPROMs are more truck specific, although have some compatability between trucks.

 

[gmctd]

GM terminology for the main controller for 6.5 Diesel products is PCM - '94-'95 OBD1 is eprom-memory based, requires replacing eprom for upgrading - '96^ OBD2 is flash-memory based, send in or exchange or replace PCM to upgrade

Powertrain Control Module controls engine, transmission, transfercase, and front axle, 'nuther words, the entire powertrain - there is one PCM for MTX (manual trans) trucks, one for ATX (auto trans) trucks, determined by a non-replaceable internal rom, similar to a mem-cal rom - all other options are determined by the replaceable eprom - eraseable\programmable read-only memory

Engine Control Module, or Engine Control Unit, controls gasser (patooie!) engines, and maybe some of their other stuff (yeah, like they even have other stuff!) - some oems have begun to use the PCM term for their newer all-in-one controllers

Electronic control module, non-caps, describes all the modules in the chassis, incl airbags, anti-lock brakes, door chimes, security, etc

GM terminology for the main controller for 6.5 Diesel products is PCM - '94-'95 OBD1 is eprom-memory based, requires replacing eprom for upgrading - '96^ OBD2 is flash-memory based, send in or exchange or replace PCM to upgrade

- never the twain shall meet....................

 

[buddy]

except in 94 and maybe 95 the fuse for it is labeled ECM, so just so yuo know which fuse it is it is called ECM, but it is really called a PCM.

 

[gmctd]

OBD1 and OBD2 uses the same fuse center as the gassers (patooie!), which is a continuation of the old NoBD fusecenters used with the emissions carburetors, then the throttle-body systems used in the truck chassis, still using that old terminology

 

[Badaxe]

So if I need to replace my PCM in my '94 K2500 Sub, will any OBD-1 PCM work? Or are there specific parameters that I must find?

 

[ak diesel driver]

good ? I would think yes as the prom is replaceable which has the engine programming

 

[THEFERMANATOR]

For the 6.5 the ECM's are specific to the diesels. 94 is one part number, and 95 is another. As far as I know though they will interchange. You will need to swap in your PROM chip though. I have an almost brand new(not reman) ECM from my BURB. It had less than 500 miles on it before my head gaskets let loose. It also had an updated PROM chip in it from GM.

 

[buddy]

Yes the 94 and 95 6.5 OBD1 PCMs interchange

 

[ak diesel driver]

Buddy the op original ? was if the pcm out of a gasser would work? I'd think the only diff would be the prom, no?

 

[THEFERMANATOR]

Buddy the op original ? was if the pcm out of a gasser would work? I'd think the only diff would be the prom, no?

COMPLETELY differrent ECM in the 6.5 than a gasser.

 

[matuva]

Would a 1994 ECM from a manual trans 6.5 fit on a 1994 with auto trans as long as you swap the chip?

 

[buddy]

Would a 1994 ECM from a manual trans 6.5 fit on a 1994 with auto trans as long as you swap the chip?

Yes

 

[matuva]

Yes

Thanks buddy