I just purchased my first diesel and not very familiar with this pcm and what it does.I have a few problems and not sure where to start to fix.I just started driving it the other day.Things not working odometer,cruise control,overdrive and the Wait to start engine light only comes on after start up and stays on.And the newest problem my alternator went Friday,I replaced it sat and it went out on Sunday.I don't have the money to just go out and buy a pcm,and that not be the problem I understand they are expensive but what do they do.I am very confused and frustrated,my excitement of owning a cummins is fading fast.Please help if you have any valuable info.I can't afford to take it to a mech.Thanks

92 Dodge d250 5.9 cummins

 

Check the crank sensor. Maybe just needs cleaned, adjusted, wires broke or disconnected.

 

If your speedo and OD aren't working, I wonder if the PCM is even getting power. I will try and find a pin out for your so you can check that. On our 91.5, I found that the fuse link for the PCM had been ripped apart buy someone. Connected it to power and everything but the OD worked. Well, turns out the PCM was fried. Getting 5V on the sensor circuit as well as the supply circuit for the APPS.

 

I have the 92 factory manual on cd that I can send pages to you if you need them