ecm issues usually throw lots of random codes so I dont think I would be quick to jump to that conclusion just yet. Can you describe what your symptoms are exactly. Are you describing dead pedal?
-
June's Cummins of the Month is now open for entries! SUMMER FUN
ECM help
Last week truck decided to run wide open. 2001 so 2500. No codes. So replaced apps. Now runs but when going down the road will cut in and out like you quickly turned key on and off have read that this could be engine mounted computer. Have cleaned cables with no results. Please help as its getting cold here in wisconsin. Throttle position doesn't seem to affect it but seems to need to be above 1500 and does it mostly around 2100
1 - 15 of 15 Posts
Next thing to check/replace while unlikely would be fuel filter. Next do you have fuel pressure gauge? the supply pressure to the VP44 should never drop below 5 psi, if it is dropping to 0 it could be the cause of your cutting out.
A future tip if your apps sensor is failing it USUALLY will only cut out at a certain rmp. The way you describe it occurring at many different throttle positions eliminates that plus its failure almost always is accompanied with codes 121 or122. To be sure use a voltmeter to monitor the voltage on the blue wire with black tracer going to apps, push throttle down very slow, let up very slow, voltage should mimic speed of throttle, not jump around sporadically this can be done driving by lengthening the signal wire.
This is that last thing that anyone ever wants to hear is injection pump. Perform the previous test while driving and if engine cuts out an voltage jumps then your sensor your got was faulty. If voltage remains steady with pedal plan on a injection pump.
I am not trying to scare you this has just been a result of my personal experience. I have 8 trucks with the VP44 pump and have witnessed almost every problem that can arise from these trucks. It sounds as if the computer on top of your pump is beginning to fail, it could last 10,000 miles (unlikely) or it might not start next time you go to start it. Even though no codes have been thrown keep an eye on them to see if any appear in the near future.
A future tip if your apps sensor is failing it USUALLY will only cut out at a certain rmp. The way you describe it occurring at many different throttle positions eliminates that plus its failure almost always is accompanied with codes 121 or122. To be sure use a voltmeter to monitor the voltage on the blue wire with black tracer going to apps, push throttle down very slow, let up very slow, voltage should mimic speed of throttle, not jump around sporadically this can be done driving by lengthening the signal wire.
This is that last thing that anyone ever wants to hear is injection pump. Perform the previous test while driving and if engine cuts out an voltage jumps then your sensor your got was faulty. If voltage remains steady with pedal plan on a injection pump.
I am not trying to scare you this has just been a result of my personal experience. I have 8 trucks with the VP44 pump and have witnessed almost every problem that can arise from these trucks. It sounds as if the computer on top of your pump is beginning to fail, it could last 10,000 miles (unlikely) or it might not start next time you go to start it. Even though no codes have been thrown keep an eye on them to see if any appear in the near future.
I just re-read your original post, when the rpm jumped, did it do it the once an hasnt since? keep updated on this symptom.
"Next thing to check/replace while unlikely would be fuel filter. Next do you have fuel pressure gauge? the supply pressure to the VP44 should never drop below 5 psi, if it is dropping to 0 it could be the cause of your cutting out."
I have to disagree with this statement, it is well accepted that vp should be supplied with no less than 14 psi at all times(except during initial starting) . That is pressure required to keep return check valve open and cooling vp44.
I have to disagree with this statement, it is well accepted that vp should be supplied with no less than 14 psi at all times(except during initial starting) . That is pressure required to keep return check valve open and cooling vp44.
Check for error codes. But a wild throttle that is uncontrolled is typically a bad ECM. I would for the sake of double checking go back over to my error code database and do the diagnostics for P0121, P0122 and P0123 to verify the APPS and ECM wiring.
So did apps re learn this evening and still same issue. Temp out side was 32 f and engine cold with com box off had plenty of Fp 15 to 12 and had same bucking issue. Issue seems to get worse as engine temp and length of drive increase. If I drive for say 1 hour condition gets really bad and will throw p0121 apps low voltage and also. Over voltage code and coolant temp code. But this is only if you stay into throttle when the bucking/surging is going on. Vp only has 59000miles on it. I have also re grounded apps sensor like ats says. When truck was a auto this took care of the tc cycle issue. Have since installed a nv4500 with no issues
Once again guys I greatly apreciate all of your wisdom
Remove that ATS ground it should not be done... You need to test the alternator and fix the AC noise issues and not modify wiring and electric system as a bandaid to a real issue. Filters, adding grounds, tinfoil are all signs of a bad alternator diode(s). Remember these truck ran 10-12 years WITHOUT this extra ground why does it need it now? Maybe because something failed? Do you fixed or bandaid it?So did apps re learn this evening and still same issue. Temp out side was 32 f and engine cold with com box off had plenty of Fp 15 to 12 and had same bucking issue. Issue seems to get worse as engine temp and length of drive increase. If I drive for say 1 hour condition gets really bad and will throw p0121 apps low voltage and also. Over voltage code and coolant temp code. But this is only if you stay into throttle when the bucking/surging is going on. Vp only has 59000miles on it. I have also re grounded apps sensor like ats says. When truck was a auto this took care of the tc cycle issue. Have since installed a nv4500 with no issues
Mopar1973Man's Dodge Cummins Articles - Torque Converter Lock/Unlock Issues
So now do the diagnostics for the P0121 to verify every thing...
Mopar1973Man's Dodge Cummins Articles - P0121 APPS Sensor Volts Do Not Agree Idle Validation Signal
Then also do the diagnostics for the ECT sensors are well.
Mopar1973Man's Dodge Cummins Articles - P0118 Engine Coolant Temperature Sensor Voltage Too High
Alternator has since been changed but will re check for ac voltage
you are getting a code for the apps and are showing dead pedal symptoms which are frequently caused by a bad apps. So I would get on over to Timbo Apps website and order one up. Resetting a bad apps often doesnt work after a point. Easy changeout maybe half hour of your time. Were there other codes present if so what were they?
Is a new apps. Has maybe 500 miles on it. Now got a p0606 ecm code and intermitten oil pressure and coolant temp
Opps... ECM is dying...Is a new apps. Has maybe 500 miles on it. Now got a p0606 ecm code and intermitten oil pressure and coolant temp
My coolant temp fluctuated like crazy was the first sign of my ecm failing. Start looking for another ecm here ro craigslist. Doesn't have to be the same year or trans if you know someone with a smarty to download the correct programming.
I'm in the same boat. Except I've put 3 rebuilt ECM's in and every one was bad. They all had different issues and only one out of the 3 was good enough to even drive the truck home from my buddy's shop
1 - 15 of 15 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Cummins Diesel Forum
A forum community dedicated to all things Cummins Diesel! Originally founded for owners and enthusiasts of Cummins powered Dodge pickups, the Cummins Forum has expanded to include ALL Cummins Engine applications! Come join the discussion about reviews, drivetrain swaps, turbos, modifications, classifieds, builds, troubleshooting, maintenance, and more!
Full Forum Listing
Top Contributors this Month
View All
the man in black
396 Replies
Jimmy N.
354 Replies
dieselenthusiast
339 Replies
