Lose RPM guage and engine has less power

[stevenh_72]

While driving my 01 Ram Cummins diesel down the road my RPM gauge will intermittently drop to 0 and the truck will start to run a little rough and seem to have less power. All the other gauges will continue to work fine. While continuing to drive the RPM gauge will start to work again and the engine begins to run smooth again and the power seem to be back to normal. The engine light is on so I checked the codes and got PCU-1693 and ECU-341. Any ideas what might be wrong or going bad?

[Clunk]

P0341 Camshaft Position (CMP) Sensor Signal
Problem with voltage signal from CMP.

I dread this one as much as any other one to show up.
This little sensor is reportedly directly under the Injector Pump...I can't see mine.
I've also read you just about have to stand on your head to get to it. The Haynes manual has a picture of it.
The P1693 means both the truck and engine computers know about this problem.