05 Dodge 3500 Cummins derate

ablokzyl · March 16, 2015

I've got an 05 Dodge with a Cummins 5.9 and a manual trans. If you drive down the road around 60mph in 5th gear and decel down to 40mph the wait to start light will come on along with a ding noise. It sends it into what I would consider a derate. It loses tons of power. Check for engine codes and there will be no memory or hard fault codes. If I take it out and drive it again it will stay in derate until I clear the codes. Any ideas? Thanks a lot in advance!

Adam

ablokzyl · March 17, 2015

I was thinking this morning about this problem. It also has a Smarty tuner and a fuel rail plug installed. He said he can remove the tuner and it will still act the same. He also installed the plug thinking that it would cure the problem. It didnt

Keith Browning · March 17, 2015

I am confused. :scratch:

You stated that there are no codes in memory yet you stated "If I take it out and drive it again it will stay in derate until I clear the codes."

ablokzyl · March 17, 2015

I know how it sounds, but there are no codes. I've checked several times with my Solus Pro. They only way it will come out of the derated mode is if I clear codes that aren't there.

lmorris · March 17, 2015

Sounds like a PCM reset or wire chaffing issue to me. Any possibility your scanner is not able to read all codes? Also is it possible there is an issue with keep alive memory? I don't know what Dodge uses for sensors or if they have VREF issues like Ford does. Known good PCM available? Just throwing some things out there.

ablokzyl · March 17, 2015

I haven't had any issues with my scan tool not being able to read certain codes, but there is always a first time. The fact that it only happens on a pretty hard decel is making me lean to a wiring chaffe issue. I don't have any spare parts or parts trucks around to swap anything out. My biggest problem is the fact that he's a pipeline welder and cant be without his truck for more than a few hours at a time.

lmorris · March 17, 2015

. My biggest problem is the fact that he's a pipeline welder and cant be without his truck for more than a few hours at a time.

In these cases, if the customer is ok with bringing it back a few times until you find the problem then it's not a problem. If he has an issue with you not being able to work within his schedule then it's his problem, not yours, and you tell him to go somewhere else. These oddball electrical issues are a bastard no matter what experience you have or what you are working on. He needs to deal with it. Also if he has a tuner, he should be able to clear his own codes and keep going until he can leave you the truck. I have no sympathy for customers that think we can magically fix everything in a couple of hours because it's their work truck.

ablokzyl · March 17, 2015

I understand exactly where your coming from. He's a buddy of mine and he will listen to what I have to say. He has been clearing them when it happens, so he can still drive it. I was just hoping for a direction to go in. I'm going to try wiggling the harnesses while its running here in my shop to see if I cant get it to act up.

cbriggs · March 18, 2015

I have very little luck with our solus pro on dodges of that vintage. I don't know why but they don't like each other.

ablokzyl · March 18, 2015

That's good to know. I do have access to the Chrysler scan tool (I believe its the DRB). We have one here at the shop that's up dated to 06. I may have to try that

sneakypete · March 21, 2015

try your DRB3 if you have one. also take a look at the battery connections. I've fixed so many Cummins due to a poor battery connection. any voltage drop and they do weird things. my brother in-laws 06 common rail lost its intake heater, transmission lost over drive and by the time he phoned wouldn't shift worth shit and also started setting bank 2 injector codes and started to buck. had him check his batteries. removed cables and cleaned reinstalled. running great now.