I have a 2001 Ram 1500 5.2L, 299,882.0 miles, yes motor was replaced a few years back. Recently it started acting up, the code was P1 391, cam or crank shaft sensors
and many other things were done by others, still have this issue, and starting to wonder if the PCM should be replaced????
I have cleared the code from memory by taking positive and negative terminals off battery, than touching them together for 30 seconds, yes I was told wrong, but it worked.

Now I found the correct way to clear it, simpler than the other way and proper way for PCM care.

All runs at times fine, notice cold starts it does display the faults, erratic idle, rpms go up and down, rough sounding idle, if you drive it doing this it just acts like starved fuel, or air, or spark even.

Have spent over a year trying to figure this out, really think I should do the PCM, cause all I get is the same code even with new parts, and now part house parts are all that I can get for some of this, as Dealers stop stocking, no supplier for factory sensor or distributor, so our local dealership said to me.

Oh the voltmeter shows the constant 5.0 volt sensor supply to be 0.04, than the key ON I got 5.14 volts, than when I started the truck the voltage went up to 5.17 and as the idle pulsated it went up and down with the RPMs, 5.14 to 5.19 volts, yesterday when it ran correctly this voltage went up to 5.21 volts, again as I increased RPMs /

 

The MOPAR crank sensors are still available for your truck and should be used in lieu of the aftermarket crank sensor, as the truck tends to be very sensitive regarding the quality of the crank sensor used. All you need is the part number. You can find the part number for your truck/engine in the parts manual for your year truck, which can be downloaded from this link - https://dodgeforum.com/forum/2nd-gen...s-manuals.html or you can call another Dodge dealer to look it up for you, as the one you spoke with was mistaken.

Once I had the part number, I was able to find one through a dealer selling them on eBay.

 

P1391 Intermittent Loss of CMP or CKP
Cam sensor is used during start then it runs off the crank sensor. Use either a mopar or delphi sensor. If the code keeps coming back hook up a scanner that can read live data and see what the pcm is seeing.

 

Thank you for the advice, as I went thru receipts, crank sensor has not been replaced to my knowledge, a new distributor from dealer, and tried a new cam sensor (made no difference) but still put the original back in, keep the new one I bought for later.

Will let all know how it turns out for me.