So my neighbor has a 2006 1500 with the hemi. Just the other day it was working great and then just died on him on the road. He pulled over and it started up and he kept driving. He got back home, parked it, and the next time he came to use it, it would barley crank. He has a brand new battery and alternator, so there’s is no problem with the charging system. We checked all the grounds on the starting circuit and cleaned up the block to battery found and still no luck, was still cranking slow. The block to battery ground cable he said started smoking before we replaced the starter when he tried to crank it. So we repacked the starter and it cranks great now.

But now it will not start. I pulled out my obd2 scan tool, and I opened up the engine rpm data. I didn’t know if the tach was supposed to dance when cranking, but it didn’t. I looked at the rpm data on my Bluetooth obd2 and I didn’t see any movement on the data. Every now and then the truck would fire just for a second and the rpm data would read that and the tack would bounce. But it would only do it for a second.

He called out a mobile mechanic and he saw the same data I saw, and he replaced the crank sensor. Still doesn’t start, and the mobile mechanic said it is the computer, and he needs a new one.

My question is, does this sound like a computer or what? And idk what brand crank sensor they put in either. Are the third gens just as picky for crank sensors as the second gens? If they didn’t put in a mopar unit should we try that and see if it changes? Or what else should we look at?

 

So you are getting no codes?
I recommend replace the camshaft position sensor and see if that fixes the problem. Camshaft sensor works with crank sensor in ignition sequence.
Regarding part brands, always good idea to go with factory. I have also had good luck with BWD (Borg Warner). BWD used to supply Chrysler/Dodge OEM.