I have a 1990 dodge half ton truck with 318 and a manual transmission but the vin code tells me it's a auto trans. Anyways I need a ecm and was thinking of purchasing one from the junk yard how would I know what would work?

 

Look at the part # on your pcm and look it up on the web, It should be for the manual. It may have been changed along with the trans if that's the case. If you need one get one for your year and drive train configuration.

 

I've interchanged manual and auto PCM's before. The only issue iv'e ever encountered is on vehicles with a shift light. It tells you to shift WAY to soon. Other than that it works.

I had a heck of a time finding one for my 90 Ramcharger (318) that's SUPPOSED to be vehicle specific. I located one off a 90 Ram Van with a 360. Worked perfectly,

I worked in scrap yards for years and learned that the Ramcharger, W/D series, and early Dakotas are interchangeable, just stick to the V8.

 

I have one in the box still if interested.