I was on a long drive home across Canada for Christmas and at the end of my drive my truck started bucking a little bit, at first I thought it was just running a little rough so I limped it the last 50km's to my parents. Look into it a little and saw the APPS reset and tried that. 

 

The next day I hop in to drive it to town and it idles fine when I am warming it up for 10min, I start to drive it and I can tell something isn't right. Bucking at any engine load, Surging up to 2500rpm when I put the clutch in, sometimes to the point it seems like I was going to break a motor mount or run away. (Never any dead pedal though, I could put to the rug and she wouldn't hesitate). As all this is happening I am trying to pull off the road and I get a CEL. I scanned immediately and got codes "P0123, P0380, P0382, P0606, P0602". I have never had a code thrown on this truck and I check quite frequently, once a week or so. 

 

So I start with the cheap problem, buying the Timbo APPS and installing that according to the provided instructions, then clearing all the codes. Start the truck and it idles but is a little jumpy (75-150rpm increases). I start driving down the problem is definitely still there bucking/surging like before. On the way back up the block back home it throws a CEL for "P0123, P0382".

 

Today I started going through all the wiring and checking continuity and voltages between the APPS, ECM and PCM. I got to "Step #11" in the "P0123 Troubleshooting Thread". Continuity and Voltages seems fine up until "Step #11" where I have 0.0V between Ground and "No.23" on "PCM Connector C1" when the truck is running.

 

Tomorrow I am going to do "Step #14" and check continuity between "PCM C1 No.23" and "ECM No.28" as well as pull and clean all the grounds and check the Alternator for AC again with a Oscilloscope. 

 

As I said I am in Canada and we can't get the $2100 ECM from the Stealership as they have been discontinued and awaiting production again. Has anyone had any luck with NPD Diesel's Remanufactured and Flashed ECM's starting to look like my only option for replacing mine if it come down to that.

 

All the After Market parts in my signature have less than 100,000km on them. 

 

Video I took today.

 

http://www.npddiesel.com/cummins-1-plugs-ecms

 

https://mopar1973man.com/cummins/articles.html/24-valve-2nd-generation_50/51_engine/obdii-error-codes_94/p0123-apps-sensor-signal-voltage-too-high-r43/

Edited January 5, 20187 yr by Colafson

There is a right up in the articles section about ECM rebuilders folks have had success with. It is in 24v/engine/electrical. I can't figure out how to post a link on this tablet. You need to be careful, there are a lot of companies that sell these that do not know what they are doing.

 

 I am willing to bet it is the ECM. I had identical problems with mine when it went though never threw a p606 like yours. Mine was like yours but on steroids. Many more codes, surging much worse and undrivable. All diagnostics I did told me every sensor on the truck was bad. I did replace the oe apps with a Timbo and 1 or 2 of the cheaper sensors that showed bad to no avail. A rebuilt ECM fixed mine.

 

I am not an ECM expert by any means. I had more symptoms than you but shared all the ones you have. It is a big ticket item and not a part you just want to throw on and hope it works. If you could get your hands on a good one you could install it and see if that fixes it then you would know for sure

Edited January 5, 20187 yr by dripley

I recommend Reman auto electronics. The Partner Company of Flight Systems Electronics.

After alot of Research( and 4 years running a bad ECM) I bought from them. Very Happy

http://www.remanautoelectronics.com/dodge/cummins-78.aspx

 

Their price is very good. Venders have been selling their ECMs for $95-400 more

 

They Remanufacture them(replace all known parts that go bad) Test for any other problems, and Upgrade to the latest software. Then they go through more testing. You get a print out of final test.

I read the article on ECM's that Dripley recommended and ended up ordering from AutoComputer Specialist out of Florida. ECM should be shipped on Monday. Thanks for your help! 

 

The ECM I pulled out of my truck is a Cummins ReCon ECM (P/N: 3947912-RX) 

 

I will continue to go through all my accessory wiring and charging system as I wait for the ECM to arrive. I will let you guys know if I find anything funky that may have contributed to the failure. 

 

I bought some KnuKonceptz battery terminals on Amazon (Link Below) and hope to clean up some of the wiring a little better. It may end up getting a new Alternator and some Optima's for the hell of it. 

 

https://www.amazon.com/KnuKonceptz-Ultimate-Positive-Battery-Terminal/dp/B00JK9FT1C

Edited January 6, 20187 yr by Colafson
Links and Pictures.

Looks like you have a Replaced Re-Manufactured ECM

Good Luck with your new ECM

Keep us Posted on how it works when you get it installed

 

 

Edited January 6, 20187 yr by GSP7

Make sure you test the alternator for AC noise. Don't Forget....

1 hour ago, Mopar1973Man said:

Make sure you test the alternator for AC noise. Don't Forget....

 

 Yes,, Make sure you dont have bad diodes in your alternator.

 

I had burnt out diodes in mine,  And my ECM was damaged also.  Could it be related....

 

I rebuilt my alt with new diode pack and new brushes and it tested good after

 

 

 

 

 

 

.

Checked the Alternator ready for A/C noise a few days ago when going through the Troubleshooting Guide with a good, yet questionable Multimeter and I am pulling out the Rigol Oscilloscope tomorrow to take a better look at it and log the information whilst I go through some RPM's. I made the decision to pull the Alternator regardless of the results and have a complete overhaul done at a very reputable local Auto Electrics Shop. I am going to have my batteries tested and if they are at the end of their life (-40°c where I work and live frequently in the winter) I will probably invest in some Optima's if they are. 

Edited January 7, 20187 yr by Colafson

I'll suggest against the Optimas...

So I finally received my ECM and got my Alternator back from the shop. I installed everything lastnight and everything is running as it should. I will keep everyone updated for the near future. I had the Auto Electric Shop bench test my batteries and they were perfectly fine so I decided not to replace them. 

 

Just out of curiosity why do you suggest against Optima's. I have only ever used them in my smaller imports and they were great for that application. Not the best battery I had though. The best was a Generic Brand Industrial Gel Cell I had in my XJ Cherokee. 

 

Also I don't recommend that anyone outside of the USA purchase an ECM from Auto Computer Specialists. The shipping to Canada was almost $300CDN for a 11"x8"x2" Parcel to my door and it took a lot longer than I anticipated. No complaints with the product, functioned as advertised. 

Edited January 28, 20187 yr by Colafson

Good to hear it is all working well again. That shipping charge does suck.