I have a Dakota 4.7 that is not starting! Code im geting is P0340. About a week ago it gave me the same problem & wouldnt start. Changed my crank sensor & it fired right up. Drove for about a week & now its doing it again! Went & got another sensor, swapped it out and still nothing. The connection at the sensor seems fine. Could it be the wiring harness?? Im stuck & could really use some help!!

 

P0340 is a camshaft sensor code - "no cam signal at pcm." You don't have fuel sync.

The cam and crank sensors are on the same 5 volt circuit however..

 

If you still have your old sensor try that just in case the one you got was a flop.

Otherwise it could be a wiring issue.

Id break out a multi meter and start testing to see if you're getting power to the Sensor.

Pray that your PCM isnt failing.

 

Do you know if there is a prefabed wiring harness that i could purchase for the cam & crank sensor? And im not sure how to test the wires with a multi meter....

 

I doubt there's one... plus it would just be as much work as checking your own.

Basically, Dan has already identified that your crank sensor is on a 5V circuit. You will want to check that you're getting the right amout of power to your sensor and signal from your pcm.

Since you said it ran great for a week with the new crank sensor... I'm willing to bet your male end of the harness (one on your engine) is corroded or has a short. This would explain why it just doesn't start anymore.

Google how to test a crank sensor with a multimeter. Does a much better job explaining it than I do Lol. Not very complicated.

 

If it's anything like a MAP sensor or Throttle Position Sensor and has a 3 wire connector, the 2 wires on the outside are 5 volts and ground inputs and the center wire is the signal.

Jimmy

 

Pins 2 (black with light blue tracer) is the ground and pin 3 (orange wire)is the 5v supply at the cam sensor.

 

had the same deal with my 97. turned up the be a loose connection. i had to zip tie the wire connector to the ignition coil.

 

The 4.7 has coil packs. It's unlikely they all failed or came loose.

 

true. but doesn't hurt to check. cheap and easy fix if that is the case.