Hi all, I am new to this site so forgive me for any mistakes or dumb questions.(LOL) I have an '02 Durango with 4.7L motor and it is 2 wheel drive.
It has a problem with ignition/distributor engine speed malfunction. The codes are PO320 & PO725. I was told that these are 5 volt circut sensors and that there are 5 of them that could possibly be bad. My question is how do I find out if my PCM is bad. Thanks for any advise.

 

P0320 No Crank Ref Signal at PCM
P0725 Engine Speed Input Circ

320 The crankshaft sensor needs to be replaced or check connections.
725 Transmission Input sensor has failed and needs to be replaced.


These are little problems and shouldn't need a whole bunch of crap replaced to fix a lil issue. Your PCM looks to be fine.

 

Thank you, Hydrashocker. I replaced the crankshaft position sensor and that did not fix problem. Then I replaced the camshaft position sensor and problem fixed. I still have a PO700 code showing up but my truck is running and driving fine, so for now I am not going to worry about it. Thank you again!

 

They work hand in hand!



P0700 EATX Ctrller DTC Present

I don't know that one? Do you mean the P0725 by mistake?

 

Nope I am sure it is PO700. Autozone told me it has to do with a transmission sensor but I don't remember exactly which one. I cleared the codes by removing negative cable then turning key all the way (like I was starting it) for 15 seconds then removed the key, hooked up cable and drove it about 19 miles. I turned the car off then restarted it and the check engine light was off. So I decided to check to see if any codes were still there (by turning the key on & off 3 times) and that PO700 showed up,which is weird because it wasn't there before I fixed the problem. The man at Autozone said if it was running and driving ok then I shouldn't worry about it. I read that sometimes it takes multiple cold starts for all codes to be cleared. So I will check it again in a few days and see if it is still there. Thanks again for your help and posts, I learned a lot from them. You sure know your Dodges!!!

 

yea something like 50-500 miles for the computer to completely reset, i think thats the range, it could be less but thats a fair estimate (i usually just give it 2 tanks of gas and be done

 

The P0700 code was most likely tripped as a result of the P0725. The P0700 is a master code and really nothing more than that. Since you know that you have an issue with the Transmission Input Sensor then that is most likely the culprit. Again, replace the sensor as they are only like $42 bucks at the dealer.


You almost correctly reset the codes. The other thing you can try is while the battery is disconnected and the start thing is done press the brake down for 30 seconds to remove any possible residual power. Then connect the battery. Reset the computer this way:

To reset your engine codes:
Remove the negative terminal of your battery (10mm wrench).
Turn your ignition key to START and hold it there for about 15 seconds.
Turn your ignition key to OFF and remove it.

Connect the negative terminal of your battery.
Start but do not hit the throttle. Idle for about 10/15 seconds then turn off.Restart the truck and drive as usual. It will take at least 12 starts and 48 miles to fully retune the computer. Hard Codes leave a shadow for 40 full cold starts.