All Deletes...Question about Exhaust Brake

[prestinb]

All,



I have completed my project of replacing downpipe and DPF pipe with 4" straight pipe. I removed the actuator from the EGR and disconnected the plug from the EGR cooler and throttle body butterfly valve per MADS directioins. I am also running a Smarty Jr. 21ME. I am so glad that I have completed this mod but have a question concerning the exhaust brake. I have it wired so that it is turned on by default. Sometimes when I start the truck it engages and has a jet sound / whistle out the exhaust. Other times it just idles like normal even though the EB is turned on. There is nothing constant as to when it happens because the engine may already be warm. Does anyone know what variable must be present in order for the EB to actuate and cause this jet sound / whistle out the tail pipe?



prestinb

 

[HBarlow]

I don't KNOW but believe it may be determined by engine coolant temperature. The EB function may be activated by the ECM to warm up the engine.

 

[jelag]

The EB on the 6. 7 will come on based on engine coolant temperature... .

We run ours all the time... it keeps the vanes on the turbo moving full stroke... .

Hope this helps...

 

[prestinb]

Thanks the reply. I was thinking along those lines but really did not have anything definitive as I could not reproduce it easily.



prestinb

 

[TDRadmin]

What is the wiring trick to to keep the brake on at all times?



Thanks in advance, Robert Patton

 

[prestinb]

Robert,



I found out how to enable my exhaust brake by default by following the directions on the link below. The information was posted on another forum and I can't thank the gentlemen (txfiremedic) enough for the great how-to. I have a 2008 and this mod worked perfect. Please enjoy and let me know if you need any help.



I ended up using the BWD part# R3177 from Oreilly's and also soldered all of my connections instead of the wire taps. Also for clarification, (I had a hard time figuring it out from the 4th picture down of it completed) the top middle pin is not used and just has heat shrink on it. It looks like a wire is coming out of the heat shrink but that is actually the red wire below it.





http://www.dieseltruckresource.com/dev/auto-exhaust-brake-mod-t251964.html?highlight=switch





prestinb

 

[HBarlow]

That's a great tip. If I owned a pickup I would be on my way to the auto parts store this evening to buy the components to rewire my exhaust brake function.

I think making "off" the default position on pickups was a mistake by Dodge or Cummins unless they had a reason that I am ignorant of.

Maybe it was because of the risk of liability due to the rare wife who would drive her husband's Ram pickup on wet pavement and potentially lose control of the truck when the rear tires broke loose under exhaust braking and automatic downshift.

 

[JHumphries]

... Maybe it was because ... the rare wife who would drive her husband's Ram pickup ...

If she, he in some cases, can't drive a truck, they shouldn't touch the it!

 

[CraigSmith]

It would be nice if they would at least offer a dealer-enabled option.

 

[MDKram]

prestinb:



I noticed the same behavior after replacing the downpipe and disconnecting the thermocouples and O2 sensors.



I have been running ME since version 14 with a Flo Pro DPF delete pipe, all thermocouples and O2 sensors remained plugged in, and required under hood disconnects as per Marco's instructions. Exhaust brake worked at idle and while slowing down - perfect. I have the relay mod done so the brake always comes on when the truck starts.



Yesterday, I replaced the downpipe and opted for the no-bung kit so I removed the thermocouples and O2 sensors. Now, I have no exhaust brake at idle but I do have exhaust while slowing down??? I don't know whether reducing back pressure in the downpipe has caused this or if the removed sensors from the downpipe and dpf delete pipe had an impact??? My troubleshoorting will start with plugging in the sensors I removed and temporarily straping them to the frame rail. If that fails, I will reload the 20ME software see if anything changes.



Marc

2008, 68RFE, Smarty 20ME

 

[prestinb]

Marc,
The only thing that has been consistent is that the exhaust brake only seems to activate at idle when it is cold out. Since it has been hot here in St Louis, it has not engaged at idle. I am curios to see what your troubleshooting reveals.

Prestinb

 

[MDKram]

I think the ambient air temperature has a greater impact on whether the brake comes on at idle than I thought. I know coolant temperature plays a role but never considered ambient which affects the intake manifold temp. This morning was cool (6*C) and the brake came on at idle as expected. Our weather has big temperature swings right now - near freezing at night and +20*C by the afternoon (35*F to 68*F). During the winter when temps are sub zero all day, the exhaust brake will always come on at idle. Anyway, there may not be a problem, just a perceived problem.