Hello everyone. I have an issue that im tearing my hair out with. So I have a 2002 Ram 2500 8.0L V10. So i was having electrical issues with it, first injectors so I replaced them, then alternator, then coils. So aftrer replacing all of those and still havinf problems I had my ECM sent in and tested, turns out it was bad. So I replaced the ecm and had it programed to my truck. All the problems stopped except for 1. I have 2 coil packs, 1 that runs 4 cylinders and 1 that runs 6. The one that runs 4 is only firing 2 of them. I have replced the coil again thinking maybe I fried it with a bad ECM but still the same problem. I seem to not be getting power to the signal wire for that coil. I tested right at the ecm with a test light. Works fine on the wire for the 2 that are firing, test light lights up and flickers like it should as it get signal, but absolutly nothing from the other wire. So what the heck could it be? all other coils are firing properly. I dont think there is a ground wire to the coils since the one on that connector is only 3 wires, a constant and 2 signal. Any advice?

 

Another bad PCM.....

 

What about a bent reluctor wheel? Would it throw a code other than the code for the coil thats not firing?

 

Not real likely, they are fairly stout.... and very well protected. Was it also misfiring on those cylinders with the previous PCM?

 

Yes, same coil through the whole ordeal

 

Might not hurt to pull the crank position sensor, and see if you can get a look at the reluctor thru the hole then..... See if there is anything interesting on the end of the sensor as well. (metal shavings..... messes with the operation of the sensor.)

Probably not the PCM then...... Probably..... I have seen companies get your PCM in, paint it, and send it back to you, with their sticker on it..... Finding a 'reliable' company to source 'em from is friggin almost impossible.

 

I actually still have my old pcm. They programmed a new one to my VIN and part number from my old one. Yes it still might be a bad pcm. But probably only if I had a bad coil that fried it again right? Or bad out of box as it does happen sometimes. I will pull the sensor to start and see what I see.

 

Careful with it though. Them fellers are gettin' hard to find too.....

 

If you can use a decent scanner you can see if there is a pulse cumming from the crank sensor. Lot easier and more reliable than just looking at it. Might want find the wire that has no signal and trace it back to the pcm. Then test the wire for a signal there. Look at the terminals on the pcm and the plug also. Video shows how to check it with a meter but you get to see it on the scanner at 7:26

 

Okay everyone. I finally was able to track down another sensor and fight with it to take it out. Those are not easy at all. Had to drop the oil pan and pry it out. While I was in there I cleaned up the reluctor and put the new sensor in. Still nothing. I saw some corrosion on the center pin of the crank sensor. I'm gonna clean that up just to cover my bases. I also have a scanner so I'll see about viewing the data like suggested if I still don't get it working.