I have a 2k 4.7 4x4 durango.
I am getting CEL's P0320- Ignition engine speed input circiut malfuntion & P0725- Engine speed sensor circuit malfuntion.

The durango is hard to start sometimes, when it does it will hardley move out of its own way. (sometimes it will start and run fine too?) Then sometimes riding down the road it will buck, then the engine will not tach over 2800...it feels like you are hitting a rev. limiter when you try?

Any ideas? I am low on cash right now, and I really dont want to go to the Stealership unless It is absolutly nessesary.

Thanks for all of your help~David

 

I am not sure what is causing that problem, but, the only electrical problem I have had with my '99 is the coil wire needed to be replaced. It had some of the same symptoms as yours, the bucking, and not wanting to start sometimes. You may want to check that out. Onece the wire was replaced, I have not had a problem.

 

welcome to the boards.
change your battery if it's stock.
I've changed my IAC valve. it's on the back of the throttle body. that helped with starting and idle'n.

do a search on those codes. try search'n those codes on google also. you may come up with a fix or two

speed sensors are easy to change. pick one up from autozone

 

Dave I have the same fault on my 2k now, Including the buck!!
I replaced the TPS and the Transmission Output sensor so far..
Last night from Dealer found out the Trans output sensor same as input so traded to input and problem stll exists.
Be nice if users posted there fix then could use the fourm history better!!


What was the over all part that was at fault??????????????????????????????

IAC??
MAP??

MBCMDR

 

I had the same problem 3 months ago on the same car. Change your fuel throttle sensor. It’s around 40 bucks at NAPA. Two screws - plug and play. Let me know how it goes.

 

Xanthl

As without manual where is the fuel throttle sensor? is it below the TPS as I already replaced the throttle position sensor. As called NAPA and he did see a fuel throttle sensor so maybe name off a bit.
I did check my fuel pressure line when problem was happening by pressing in the item that looks like tire air needle value and fuel came out under pressure so figure fuel pump was ok.

I do thank you for the help!!
MBCMDR

 

Sorry for late response.

The sensor I changed was on the driver side of the engine and was just above the rear most (or next to rear most) sparkplug and coil. It had two star shaped screws holding it in place, was connected to a small cable assembly that just snapped on, and took about 10 minutes to swap out. If the process you used to change out the throttle position sensor sounds like this, then yes we are definitely talking about the same thing. If that’s the case then I do not have any other advice to give you.

 

There is another sensor that you may need to replace. I think it is called a speed sensor that is located at the top of the rear axle. When I replaced the transmission output sensor, the durango still did not seem to drive too smooth and then decide to change the other speed sensor located at the rear axle. Now everything drives normal.

I would suggest to anyone to change out both sensors if only one of the two are out just to cover any future problems. TPS sensor is another common problem mainly for those that uses cruise control where you the engine wants to briefly surge.

 

Just a note the Po320 is crank sensor code, when using after market scan tools they seem to use their own slang.

P0320-NO CRANK REFERENCE SIGNAL AT PCM.

Possible causes

CKP SIGNAL CIRCUIT SHORTED TO VOLTAGE
TONE WHEEL/FLEX PLATE DAMAGED
5 VOLT SUPPLY CIRCUIT OPEN
IRREGULAR LAB SCOPE PATTERN OF CKP SIGNAL
STRAY SIGNAL FROM THE CAMSHAFT POSITION SENSOR
WIRING HARNESS INTERMITTENT
SENSOR GROUND CIRCUIT OPEN
CKP SIGNAL CIRCUIT OPEN
CKP SIGNAL CIRCUIT SHORTED TO GROUND
5 VOLT SUPPLY CIRCUIT SHORTED TO CKP SIGNAL CIRCUIT
CKP SIGNAL CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
POWERTRAIN CONTROL MODULE (CKP SIGNAL CIRCUIT)
POWERTRAIN CONTROL MODULE (SENSOR GROUND CIRCUIT)
CRANKSHAFT POSITION SENSOR

 

Hmm, seems to be a common problem. I have a 2K 4.7 Dakota. My battery went dead. I think I killed it, the window was left open in a snow storm, and I had left two power cables plugged into the sockets for phone and iPAQ, but there ends were not connected at the time. Next day, my batter was dead. I can only assume snow got into the cables and shorted out.

Truck has 88,000 mi on it. I had never had a battery problem before, but it was dead. I think, however, shorting the connections may have caused corrosion to build at the terminals. Even a new battery didn't work till the terminals were cleaned. So in fact, the old battery may have been ok. I had never changed it before in 5 years, so I figured I'd change it anyway. But since, then, the check engine light has been coming on and engine has been having problems (engine chugs when I try to give it gas), but only when it is cold out (<25F) and first time I drive it in the day. And often if I shut the engine off and turn it back on, the light is off and engine runs fine.

I did have some issues over the last couple of years getting the truck to start when it was damp out if I had driven a couple of miles and turned the truck off. When I would try to start it again, it would not start up. If I waited a few minutes, it would. Problem was verrryyy rare, though.

Anyway, after I killed the battery and had it replaced, this cold engine thing has been happening whenever it is cold out. I just tried to have it inspected (MA) and it said it has codes P0320 and P0725. Unfortunately, check engine light causes emissions failure in MA. Perhaps if I bring it back and show light is off, they'll pass it (even though I know it will come back on again when it is cold).

Any thoughts as to what is going on here? Why does it seem to be temperature related? Is there a problem I introduced when I changed the battery (the problem started after that, the check engine light came on then for the first time)?

Thanks,

Thomas