While towing a heavy load for several days my tack quit working, engine kept running. I shut down the engine when I pulled in to fill it up and the truck would not start again. Check codes and have P0320 with a scan tool and MIL 11 using the key on off three times. I found the tack wire slightly melted and grounding into a AC request relay wire in the wiring harness just down stream from the PCM. I fixed that of course and have replaced the Crank Sensor, Cam Sensor, checked continuity and ground to both sensors completely. No issues there. I also replaced the PCM. I get the same codes with both PCMs. I've ohm check both coil packs they are good. The ASD relay is working when jumped out but the PCM is not pulling it in for some reason when cranking or with just the key on.
Any ideas?
Thank you

 

P0320 No Crank Ref Signal at PCM

11 is the same.

Are you getting 5 volts TO the sensor?

 

Yes 5.43V at the back of the PCM. I was able to get like 1.5 volts on the signal wire if I bumped the engine over to just the right spot on the cam sensor. Wasn't really able to see a voltage change on the crank sensor by bumping it over. Maybe I should have used a wrench at the crank and went real slow. I'm pretty sure the sensors are good. I'm missing something else I think. Do you know if the tack is burned out would that through off the PCM? I going to look into that circuit next I think.

 

PCM tells the tach where to move the needle. If the PCM isn't getting signal from the crank sensor, the tach likely won't move either. I don't think the PCM cares if the tach is actually working or not.

Crank sensor sends a square-wave signal to the PCM. (its just a hall-effect switch....) If the signal is weak, or inconsistent, then the engine won't run worth a darn.

What brand sensors did you get? These trucks really don't care for the aftermarket fellers...... really need to get sensors from the dealer.

 

The sensors were not from Mopar they were both made by "Walker" which I have used in the past for O2 sensors with out issue but this may be a different animal. I will bite the bullet and try a set from the dealer. I still have the original Cam Sensor which is probably okay, but broke the tab off the Crank Sensor while trying to get it out from behind the motor mount.
In other research I've read others saying the same thing about the aftermarket on these sensors.
Thanks for the reply

 

Let us know if it improves your situation at all.

Careful with the cam sensor install. It's way to easy to do it wrong, and snap the little feller off first time you crank the engine.

 

Okay I'll check the Cam Sensor I installed. Also I have been looking for a new MOPAR set of sensors. They have been discontinued. Looks like the aftermarket is my only choice unless I get lucky some how and find one on somebody's shelf

 

Check Ebay, and Amazon.

 

I haven't checked Amazon yet but I did check eBay and a couple of MOPAR only sites all MOPAR say "discontinued". I also checked the Cam Sensor I installed and I did wipe off a little bit of the tip. I've dug into my service manual further and found out how to install it correctly. First time I just slammed it in there and tightened it up. I going to try to get a genuine MOPAR replacement for both this week.
Thank You for all your help

 

This place supposedly has the crank sensor, I would call and ask first though. Of the hundreds of other sites that come up, I find it highly suspicious that ALL of their pages look EXACTLY the same...... I think they are plugging into the same database.....