Simultaneous idle-up, turbo and exhaust brake activation

[ViperClaw]

I live in Fairbanks, AK and own a 2014 2500 Laramie mega-cab (2,900 miles). I have experienced the following random anomaly numerous times:

On occasion, the truck will automatically place the engine in idle-up and activate both the turbo-charger and exhaust brake. Coupled with this anomaly, the entire cab will fill with an overwhelming pre-treated diesel exhaust odor. This event has occurred at ambient temperatures as low as -36 and as high as 75, as well as an internal coolant temperature as low as 90 and as high as 194. There is no visual evidence of exhaust brake activation (ie, the indicator light), only audible cues. There are four conditions that, once met, will remove the anomaly; albeit only temporarily for three out of the four:

1. Step on the brake -- This removes the anomaly until you release the brake pedal, thereby returning to the previous condition.

2. Exceed 1800 rpm -- Like condition 1, this removes the anomaly until the RPMs drop below 1800.

3. Exceed 20 mph -- During the acceleration to 20 mph, the truck suffers a severe reduction in power coupled with an increase in boost pressure, regardless of throttle position/setting (low, med, high). Upon reaching 20mph, the turbo will wind-out (sometimes as high as 18psi boost pressure) before resuming normal operation. Subsequently dropping below 20 mph will resume the anomaly.

4. Shut off the engine and allow a complete electronics time-out -- This process requires approximately 10 minutes to execute. Simply restarting the engine is not enough to remove the anomaly. Upon restarting the engine after 10 minutes, the anomaly will usually be removed for at least the next driving cycle.

This anomaly has occurred during various stages of driving cycles ranging from initial start-up, remote start-up, and at various levels of operation during normal driving. I have tried to duplicate the anomaly with zero success (self-activation of both idle-up and the exhaust brake). Also, there does not appear to be a set duration for the anomaly's presence -- it goes away when it wants.

I read similar threads for earlier Rams that discussed a DPF regeneration. I do not think that is the case for my issue because there are ZERO EVIC messages indicating that anything is happening to the exhaust system; DPF, DEF or otherwise. In addition, there are ZERO maintenance or engine fault codes generated by this anomaly. The dealership has replaced the PCM and applied various software patches to no avail.

Thoughts?

 

[AH64ID]

It sounds like the net zero idling. Is it going to 900 rpms?

The exhaust brake and turbo are one in the same, as the exhaust brake is a function of the VGT turbo.

Unless the DPF gets to 80% full you will not get any in cab notifications of a regen.

 

[ViperClaw]

During the anomaly, it idles near 1,000 rpm -- near 975.

 

[AH64ID]

Sounds like net zero or net reduction idling, and should be perfectly normal.

I thought the engine had to be warm, but that was on the older 6.7's.

 

[ViperClaw]

Pardon my ignorance, but what is net zero idling? This is my first diesel -- I love it, but there is a LOT that I do not know.

 

[AH64ID]

It is an idling mode that reduces the soot buildup in the DPF. There isn't much info on it on recent trucks, but it came out in 2008 for the 6.7 and sounds like what you are describing.

How long are you idling it for when it occurs?

There is net zero and net reduction. Net zero is like a zero emissions idle and net reduction is a mini regen.

From the owners manual/diesel supplement.

If the engine is allowed to idle, under some conditions
the idle speed may increase to 900 RPM then return to
normal idle speed. This is normal operation.

 

[ViperClaw]

Thanks for the info.

The condition has occurred at various times during initial start-up (30 seconds to 5 minutes post start-up), after periods of highway driving, and after periods of city driving and idling -- there is no set pattern or criteria for it to occur.

When I notice it occur, I have usually either shut the truck down and waited for ten minutes until everything clears, or simply gone about my business with the windows down (for the exhaust odor) and suffered through the power reduction during acceleration. The condition seems to go away on its own each time, but I do not have any data (yet) on the duration for which it lasts. I have not seen if the condition will clear on its own by simply idling.

 

[AH64ID]

Some of that also sounds like standard cold fast idle operation, so maybe not always the net zero/net reduction.

With cold/cool coolant and cold ambient temps the engine rpms will increase to 1,000 to help warm the engine up (it's potentially very hard on diesel engines to idle cold more than 3-5 minutes).

 

[ViperClaw]

I've experienced the standard cold fast idle many times this past winter. During each of those activations, the exhaust brake/turbo is never activated. During the anomaly that has me perplexed, the exhaust brake/turbo is always activated; you can clearly hear the turbo spool-up (whine) combined with a noticable increase in engine noise (sounds exactly like the exhaust brake working).

 

[Badunit]

From the Diesel Supplement Manual under cold weather starting: "Engine idle speed will automatically increase to 1,000 RPM and engage the Variable Geometry Turbocharger at low coolant temperatures to improve engine warm- up"

 

[ViperClaw]

Hey there Badunit, thanks for the reply. I also read the same verbiage in the supplement and thought I had it nailed -- until it occurred at coolant temperatures as high as 194 degrees; well into the normal operating range and after an hour of driving. It is quite strange.

 

[Badunit]

I meant to add some more to my post but got distracted. What I was going to suggest is that it sounds like the action is something that is programmed into the computer (i.e., normal) but it is getting triggered incorrectly. Maybe a bad sensor, loose connection, or something of that nature. Or could be a glitch in the computer itself.

 

[Ozymandias]

What do you do with your Truck, Trailer, Commuter, very short Trips, a lot of idling?

 

[RVTRKN]

Well don't wait to long to take it to the dealer. I did with mine and have been kicking myself in the butt every time my 07 C&C goes into regen. I know when its in regen by the surging and sticking RPM's driving through the city. The first clue is when I come to a stop and engage the clutch or go to neutral at a light and the EB will come on and it can stumble when I go to accelerate, and when at 2000 RPM while accelerating it will take off on its own and nothing will stop it, not even depressing the clutch, for the RPM's will just sit at 3200 RPM for what seems like an eternatiy, but is like a second or two. While updating the ECM, hoping to eliminate this, under complimentary service the tech replied "two bad its not under warranty". DONT SIT ON IT, when its out of warranty, "it's too bad, so sad" and Dodge could care less.

 

[DonFitzwater]

That smell you are getting may be burn in on the exhaust components. Mine smelled pretty bad when new until I towed an excavator to Valdez last summer and burned it all off. I was almost certain it was an exhaust leak or regen hiccup of some sort.

My truck will ramp up the idle automatically, even when coolant temps are high, dependent on ambient temps. Last summer it would always maintain specific idle and the only other item of interest is when the fan clutch kicks in you can really hear it.

Swing by The Boat Shop some time and we can take a look and compare trucks and how they behave.

 

[AH64ID]

Hey there Badunit, thanks for the reply. I also read the same verbiage in the supplement and thought I had it nailed -- until it occurred at coolant temperatures as high as 194 degrees; well into the normal operating range and after an hour of driving. It is quite strange.

What was the ambient temp?

 

[TCDiesel]

2013 Up truck may ramp Idle and engage ACTIVE REGEN, this will shut the EGR and turn on Turbo Brake TB/EB, it generally will do this in extreme cold, Last Winter when -38 below in West Yellowstone , I spent 3 days getting a Groomer Back to town, My 13 idle for 4-8hr each day on the last day it went into Active Regen at idle, it also did this the year prior when idling for 4+ hrs in -20 temps in MN on service calls.

The TB/EB will also by default engage when condition are met WITHOUT Active Regen.

The other issues Hmmm reduction in power and increase Boost, I think the TB/EB is stuck or is sticking. couple that with EGR problem just compounds the problem.

 

[Newsa]

I have noticed an occasional louder (slightly faster) idle. I was wondering if it was a regen function. But thought regens only occur at highway speeds.

I will check the turbo and e brake EVIC screens next time I experience that

 

[TCDiesel]

The EVIC/turbo will tell you nothing concerning Active Regen, EGR will be 0% and the turbo you will hear, and the stink is the give away.

 

[JLandry]

The EVIC/turbo will tell you nothing concerning Active Regen...

That's where something like an Edge Insite comes in handy. The display shows you when a regen is occurring.