For some reason, my '01 4.7 4x4 burns through the sensors. I have replaced two in the last year. Last week, it acted up again, just like before, so I installed a new sensor. Nothing! Still cranks and cranks, but won't fire. I pulled the codes, first one is P0340 Crankshaft Position Sensor circuit. I'm stumped.

Is there a relay or fuse that could be causing this? Hope not just a loose or broken wire, don't have time to try tracing that maze. I guess theoretically the new sensor could be bad also.....

Any helpful tips, please?

 

Do they look damaged in any way inspect the sensor after pulling it out.

Post a few Pic's if damage is found.

 

They never looked damaged, just some oil on on them, otherwise fine.

 

I'm curious as to if they are the same brand? Try another.

The CKP and CPS both run off the same 5 volt feed from the PCM.

 

Ok, I'm drawing a total blank here, what is the CKP?

I thought of testing the CPS plug to see if there is power there, but is that dependent on the key position? Is the power supply constant?

 

So...I just went out again and messed with the wires going into the plug, nothing seemed loose, but the truck started up immediately after that. Guess it is a simple wiring problem. Probably.

 

CKP - crank position sensor
CPS - camshaft position sensor

 

Thanks, DakDan. Finally had time to see your reply, because the truck did it again. I changed the CPK (put the one I took out last month back in) nothing. disconnected the plug, pushed all the wires back in, nothing.

Very frustrated and confused. Thinking about replacing the wiring and the plug, but doesn't look like Advance has that part in stock. Is there something else that could be causing this? I'm reasonable certain it's not the CPK itself. Fuse?

 

OOPS, Meant CPS this morning.

And an update a few hours later. couldn't find any loose wires of fuse issues, but couldn't figure out which fuse would connect to the CPS either. Pulled the P-codes by turning the ignition to the on position three times. No code for the CPS but the first one is for the CKP now, never was before.
However, immediately after pulling the codes, I turned the key and the truck fired up. Very weird. Is it possible that pulling the codes does some sort of a reset that allows the truck to fire? It did the same thing the last time, although I didn't try to start it immediately after pulling the codes, it was a few minutes later, after I checked the wires, basically the reverse of what I just did.

 

Had CPS go out a Few years ago. Truck would not start. Went back to it the following day and gave it a love tap with a screwdriver handle. Fired right off.
Because it was winter, snowing and cold I took it to Dodge. They recommended to replace both cam and crank sensor. Have had no problem since. 169769k miles now.
Have you used OE or commie parts?