Oddest thing I have ever seen...HELP
 

I have a 1994 6.5 TD and am having issues with that I think is the PMD. Its new, relocated to behind the front bumper and it stays pretty cool. Yet I am still having the same symptoms with the shutting off at random, and sometimes over and over everythime I slow down... Other issue has me completely stumped. Every time I start, put it in gear, and go, it will not shift into 3rd/overdrive for about 5 minutes or more untill the check engine light comes on. no matter what temp it is, cold or hot. It can shut off going down the road (as the PMD issue) I can throw it in neutral and restart, then I have to wait all over again for the check engine light to come on for it to go into overdrive.... I am at a loss, about ready to throw a match into the fuel tank! PLEASE HELP!!!:argh:

Pull the codes and post them.

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I don't know why there are no stickies on this forum but this should be one.
This only works for OBD1 94-95 trucks.
https://www.dieselbombers.com/chevy-...ead-codes.html
Jump pins a and b

I tried, but for some reason there is no power going to the plug so I cant get a reader to even work on it

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Anyone ever had this issue with the tranny ot the computer port?

That probably is your problem. check the ecm fuses. Otherwise your ecm might be fried.
What reader are you using ? an OBD2 reader will NOT work.
If you get in and turn the key on without starting it do you see the ses light ?

Ignition switches fail and in some cases the lighter fuse powers the ALDL.

If the ecm fuse is blown a scanner won't work. Had it happen on an OBD1. Guy replaced his inj pump and still couldnt get it started. I hooked up GMTDScan and could not connect. I check the ecm fuse. Was blown. I put a new fuse in and the truck fired right up. He was pissed...:tu:
Spent 1,000$ for 50 cent fuse...lol
Being that you have the SES light coming on probably not that but ecm could have issues if you cant pull codes.

All the fuses are good to go. Took it to orreileys and the guy got one reader, when I told him it was a 94, he went and got a different reader. I am not very well versed in this field, but if u tell me which is the correct one, I will take it back up there and try again. Also, does the check engine light have to be on in order for the code to show up, or is it automatically stored in the PCM? And will the reader be able to tell me if the PMD is good or not? Thanks a lot for the help gentlemen!

The check engine light does not hav to be lit for codes to be stored in the ECM,also a code reader will NOT diagnose a PMD-some codes can be related to a failing PMD but ther is no PMD specific code.
Replacing a PMD with a known working PMD is the only accurate diagnosis of a bad PMD when the good 1 corrects the problem.

I have a similar situation going on now. a '94 I am told is an obd1, and you need to jump the top two terminals on the right side of the hookup as you look at it *like you are looking at the pedals. Have the key to run as you do this and you need to count the numger of times the 'service engine' light flashes. I got a 'flash, flash, flash, pause then six more flashes... then did it again... and again... = 36. thats what i got, try it and see what you get. I was told a part in the injector pump could be at fault so replace it, I am in the process... I havent tried the PMD but I will before I go for the IP replacement, so check your code, oh yeah, use a paperclip to do the check, confused? So was I... but I finally found someone with the answer I needed here on the forum...:tu:

Tried it and got a 15. Think that's a engine coolant level... now I am more stumped than ever. What if there are multiple codes? I have no indication that its running hot, bubbling over etc. etc. So that tells me nothing of the overdrive problem, nor the shutting off at random. Starting to wander what Chevy had in mind when they made these, was crack cheap in 1994??