Last year I replaced my PCM and didn't do a very neat job with the burnt fuse links and harnesses at the time, so I thought I would clean that up today. When I tried to remove the connector bolt, it turned but didn't want to come out. To make a stupid story short, the bolt is still in there, and now it won't go either direction. I tried everything I could think of that wouldn't damage the electronics all around it. I remember that 60-way connector was pretty tight on the pins and thought maybe the bolt was out as far as needed, but I quit prying when plastic started breaking.

I buttoned everything up and the truck seems to run fine.
I got an error code (12) from the check engine light, but it's not listed in the books or in the code list that came with the PCM. I could be misreading "21" but that's for gas motors. Does that mean NAPA gave me the wrong PCM?
If anyone has ever heard of this connector problem, and has a solution, please let me know.

Thanks for the forum. It's hard to find advice on these trucks, and this forum has tons of it.

'93 W250. Flatbed, otherwise stock.

 

Not sure I'm remembering correctly , but I think that for that yr , 12 was clear of codes .
I think that the nut that the bolt is screwing into is spinning , a yr ago from Napa , may be out of warentee .
If its working I would put some duct tape on to make sure that it does not come apart , in a unwanted time .

 

I believe 12 is "battery disconnected in last 50 starts" then the companion code 55.

 

OK, I'm going to use my psychic powers to "read" your truck. John, I'm feeling like you did something with a 1/2" wrench - possibly involving the battery? Ive got it! You disconnected the battery before working on the electrical system, didn't you? See, I told you I was psychic.


























That's what code 12 means -battery connection disturbed within the last 50 starts.

 

Dagnabbit loch! You beat me to it!

 

I'm sorry Dave, but the psychic power was over whelming me, I just had to post that,

 

I've got it zip tied together. Next time the book says don't overtighten, I'll find a torque wrench.
Thanks for your responses. As long as you're feeling psychic, maybe you can find the mysterious fuel leak I've been looking for...

 

D-ring between fuel heater and head????

 

Even psycics need a bit more help than just fuel leak.