[KellyLee]

Been a long time since I've been on here.

Anyway, having trouble with my '00 Dakota, 4.7, auto, 2wd, 190k. First time I've ever had any running issue with this truck.

So, driving home on the interstate at about 65mph. All of a sudden it started bucking and felt like the transmission was going out. Paid attention and noticed the rpm's were dropping when doing it. Limped it home and code P1391 showed up. I know this is the intermittent loss off cam or crank sensor.

Ok, I ordered both sensors from RA, installed them, no change and still have code. Hmm, found someone that said theirs did it and the dealer replaced about 18" of wire and the plug for the cam sensor so I did the same. No change and the code lives.

I guess it could be the crank plug/wiring, or even somewhere else in the wiring, but instead of just replacing pieces at random, how do I actually trace where the problem is? I have my OEM service manual and located the pin outs for each sensor and where they go in to the ECM. I know there is a ground, a 5v power, and then the sensor wire for the cam/crank sensor.

Anyway, what type of signal should be passing out of each sensor? Is it voltage or an ohm reading I'm looking for? I read on here that another guy fixed his and it turned out to be the TPS even though I have no clue how that relates.

I'm looking for any help I can get with this as it's driving me crazy. I want a sure fire way to actually diagnose the issue and stop the BS "it might be this so replace it" crap I'm going through now. Thanks.

EDIT: Just for extra info... timing chains, adjusters, and followers all recently replaced. Throttle body and IAC valve thoroughly cleaned.

 

[Dart73]

Been a long time since I've been on here.

Anyway, having trouble with my '00 Dakota, 4.7, auto, 2wd, 190k. First time I've ever had any running issue with this truck.

So, driving home on the interstate at about 65mph. All of a sudden it started bucking and felt like the transmission was going out. Paid attention and noticed the rpm's were dropping when doing it. Limped it home and code P1391 showed up. I know this is the intermittent loss off cam or crank sensor.

Ok, I ordered both sensors from RA, installed them, no change and still have code. Hmm, found someone that said theirs did it and the dealer replaced about 18" of wire and the plug for the cam sensor so I did the same. No change and the code lives.

I guess it could be the crank plug/wiring, or even somewhere else in the wiring, but instead of just replacing pieces at random, how do I actually trace where the problem is? I have my OEM service manual and located the pin outs for each sensor and where they go in to the ECM. I know there is a ground, a 5v power, and then the sensor wire for the cam/crank sensor.

Anyway, what type of signal should be passing out of each sensor? Is it voltage or an ohm reading I'm looking for? I read on here that another guy fixed his and it turned out to be the TPS even though I have no clue how that relates.

I'm looking for any help I can get with this as it's driving me crazy. I want a sure fire way to actually diagnose the issue and stop the BS "it might be this so replace it" crap I'm going through now. Thanks.

Just came across this:

5/06/2014 23:31:21

RE: Code P1391 IP: Logged Message: I was fighting with similar issue in the last 5 weeks, the problem starts when I replace the crankshaft position sensor. I went to 5 different shops and none could fix it, after check vacuum leakage, timing, wires and connections I decide to replace cps again and get a Mopar part. The code, hesitation, misfire simply disappear and truck is alive again.

EDIT: Just for extra info... timing chains, adjusters, and followers all recently replaced. Throttle body and IAC valve thoroughly cleaned.

 

[nightmare]

There are 4 or 5 different sensors on that same circuit; crank sensor, camshaft sensor, throttle position sensor, idle air control valve, and maybe the battery temp sensor and MAP sensor.

Went through this on my 02 Durango with the 360, so maybe a little different, but replacing the camshaft sensor and the MAP sensor allowed it to start and drive. IIRC, each sensor had a 5v wire. Make sure you are getting 5v at that connector before the sensor. And definitely make sure you are using a Mopar part.

 

[KellyLee]

Thanks for the input.

I tested the camshaft sensor wiring. Ground connection appears near perfect and got a constant 5.1-5.2 volts at the sensor and tested the connection all the way to the computer. I didn't see any fluctuation on them while the engine was running yet it was still missing. Just didn't know what the reading should be on the actual "sensing" wire should be.

I guess I'll order up some genuine Mopar sensors as I've read several times that aftermarket ones can cause issues. I promise to do a follow up as I hate when people ask questions but never come back and say what solved it.

Any more input/insight is greatly appreciated!

 

[KellyLee]

Well, I said I would so here it goes... the follow up! Ordered both genuine Mopar cam and crank sensors. Installed cam sensor, same problem. Installed crank sensor, now she purrs again!

It honestly shocks me that the aftermarket can't make a decent sensor for our Dodges. From now on I will only put genuine Mopar sensors in my Dakota!

 

[immattj]

For a 2000 I think you were lucky to find Mopar crank & cam pos sensors. When I did the cmp sensor for my '03, the best I couid do was an SMP sensor and although, at that time, I was able to buy a Mopar ckp sensor, the last time I looked on Rock they didn't have Mopar for my year and engine.

 

[KellyLee]

Yeah, I didn't buy from RA since they didn't carry the them. Cost me about $140 for the pair but at least they were genuine Mopar.

 

[immattj]

Reliability is worth a few extra bucks.
Did you buy from a dealership?
As I typed, different year and different engine, but when I did go to a dealership for the cmp sensor, they told me Mopar wasn't even making it for my application anymore.

 

[KellyLee]

I ordered through Mopar Store on Amazon. One of the few times I have trusted Amazon to get a genuine part and, comparing to my OEM part, it looks to be the real deal and the truck runs great. Just got back from doing some running around and no codes or hiccups.

 

[immattj]

Thanks. I'll take a look over there myself.