Update: I decided to replace the full path from the PCM to the crank sensor that was shorted. Identified wires in C2 harness off of PCM and replaced from the PCM down to the sensor. Once I replaced, retested everything for correct 5.00v, and resistance to ground. All was good. Hooked it all back up, cleared PCM, then tried to start the truck. It started ran rough, gave me ETC light. Then kicked out codes P0198, P0520, P0340. None of these codes were present before, I double checked the voltages on the MAP, cam, crank, and Oil pressure sensors, they are fine, no more electrical issues.

Ordered a replacement PCM/ECU today, as it's the only culprit remaining especially after getting multiple strange codes all at once. My guess is that the original short on the crank sensor wires near the oil filter did my PCM in, or it just died...never know for sure.

I'll put up a response when I install the new PCM see if that corrects everything, I'm hopeful it will.

 

New PCM coming Tuesday! Fingers crossed it works...

 

I wish you the best of luck, i don't understand electronics

 

Sounds like you have done an excellent job on the trouble shooting so far!
Have checked all the chassis grounds lately? The reason I asked is a friend of mine was having similar issues as yours(chasing different codes every time the truck started) while we waiting on the new pcm I pulled off all the grounds and sanded them off especially the ring terminals they looked good to the eye but once you tool them apart there were pretty oxidized, we put the old pcm back in to double fuel pressure the truck fired up and hasnt had an issue sense.

 

Thanks man, I might as well do that to rule it out, I really want my truck back...and it's snowing!!! I can't go play in it with my Ram..

 

Update:

New discovery. After replacing all the wires for the crank sensor and BEFORE installing my new PCM I decided to make sure all the grounds were good in the truck. First thing I tested was the cam sensor ground as these two seem to work in unison. Glad I checked too, because NO GROUND on my cam sensor.

I did find a wire diagram for the sensors in the rig, the crank and cam sensors share a common ground wire. So when I cut out the shorted crank wires, I also removed the ground for the cam sensor. So...now I'm going to add a ground back in to the PCM for the cam sensor. I'm doing that today along with new PCM install, hopefully this should do it. Everything else checks out, other than i noticed my dang water pump has started leaking...at least that doesn't require anymore wiring troubleshooting...

I'll put a post up and let you all know how it goes.

 

Okay well another 5 hours of trouble shooting has let me to now realize the 5v supply that I cut to replace for the crank sensor also powers the throttle body, and accelerator pedal position sensor. Ran new wire off of the PCM harness to these and then started the truck after hooking the battery and harness back up. Ran fine, normal idle, pedal response was fine.

Next issue...the truck then threw a bunch of codes at me for "circuit high". This leads me to believe that the "K900" ground wire I cut to replace was also a shared ground for other sensors. I'm hoping someone has some wiring diagrams for me so I can verify ground on some of these sensors and make sure I'm heading in the right direction here.

P0406 - EGR
P0113 - Intake temp
P0523 - Oil pressure
P0198 - Oil tem
P0118 - MAP

I did find one document on the web that shows what is used by the K900 ground wire located in the PCM slot C2 pin #27. But I'm not sure what year it's for, so I don't want to assume it's correct. Any help would be much appreciated. Thanks all.

 

I think I have found the info on the ground...splicing tomorrow to reground all these sensors. Hopefully my electrical nightmare will be over after that.

 

Well very very happy to report I'm now back on the road. Ol girl just needed some wiring love. Verified my PCM was not the cause just the short on the 5v power supply system that runs to the Trottle Body, Accelerator Pedal Position Sensor, Crankshaft Position Sensor, and the Oil Pressure Sensor. For any of you having wiring trouble or the dreaded ETC light check these wires!! I would wager to say there are A LOT of 3G Hemi Rams out there with wires rubbing on the block right next to the oil filter.

In addition to the power supply I also ran new ground and signal wires to the crankshaft sensor. After that it was test and re-test for all the other sensors to ensure ground and power were there for them.

FYI:
The 5v power supply for the APPS, Throttle Body, Oil Pressure Sensor, and Crankshaft Sensor all run back to the Orange C2 plug (second from the top on your PCM) pin #29.

The ground for these sensors and MANY others is also located in the Orange C2 plug (second from the top on your PCM) pin #27.

If you're wanting to check the harness for continuity on the wires, or check resistance the service manual will recommend "Miller Special Tool #8815" so you don't damage the female pins in the pig tail connector. I accomplished this task by using a set of small metal picks similar to what a dentist would use, and very gently just touched the face of the pin in the harness, and was able to get resistance readings just fine on my meter.

A lot of solder, heat shrink, and wire loom later...it's fixed...

Oh, I am going with the new PCM even though my old one is okay. It has all the latest updates on it (which i very badly needed) and restock fee offsets my costs for returning it and paying the dealer to flash mine. My truck felt like it never has, shifted so much better, especially through 1-2, and 2-3. Before it would get a little confused as to what gear it wanted at times, like it wouldn't hold on to 1st long enough jump to 2nd, then back to 1st. Now it's great, shifts like you'd expect it to.

Anyway hope this helps somebody.

 

Well very very happy to report I'm now back on the road. Ol girl just needed some wiring love. Verified my PCM was not the cause just the short on the 5v power supply system that runs to the Trottle Body, Accelerator Pedal Position Sensor, Crankshaft Position Sensor, and the Oil Pressure Sensor. For any of you having wiring trouble or the dreaded ETC light check these wires!! I would wager to say there are A LOT of 3G Hemi Rams out there with wires rubbing on the block right next to the oil filter.

In addition to the power supply I also ran new ground and signal wires to the crankshaft sensor. After that it was test and re-test for all the other sensors to ensure ground and power were there for them.

FYI:
The 5v power supply for the APPS, Throttle Body, Oil Pressure Sensor, and Crankshaft Sensor all run back to the Orange C2 plug (second from the top on your PCM) pin #29.

The ground for these sensors and MANY others is also located in the Orange C2 plug (second from the top on your PCM) pin #27.

If you're wanting to check the harness for continuity on the wires, or check resistance the service manual will recommend "Miller Special Tool #8815" so you don't damage the female pins in the pig tail connector. I accomplished this task by using a set of small metal picks similar to what a dentist would use, and very gently just touched the face of the pin in the harness, and was able to get resistance readings just fine on my meter.

A lot of solder, heat shrink, and wire loom later...it's fixed...

Oh, I am going with the new PCM even though my old one is okay. It has all the latest updates on it (which i very badly needed) and restock fee offsets my costs for returning it and paying the dealer to flash mine. My truck felt like it never has, shifted so much better, especially through 1-2, and 2-3. Before it would get a little confused as to what gear it wanted at times, like it wouldn't hold on to 1st long enough jump to 2nd, then back to 1st. Now it's great, shifts like you'd expect it to.

Anyway hope this helps somebody.

Mine doing the samething, do you have the diagram for this? Was easy replace the wires and what gauge should I put?

 

my 5 volts do not show up anywhere on my harness, does the pcm supply the 5 volts to the sensor system. if so would you see it on the pcm pin if you disconnected all of the harness wires and manually applied 12 volts and ground from the battery to the pcm

 

Great post OP this was exactly my problem! Helps a lot!