How to Get the Exhaust Brake to Work at Low Speed

[tmcIlwain]

Unfortunately, you don't. It just won't work below 20mph. I tow extensively and have tried every possible configuration on both of my trucks. The EB just won't stay on below 20mph. The '14 with the 68rfe is a real pain in the *** to use the EB. Sometimes it drops out at 50, most of the time if I use it down to 45 or so, then hit the throttle to maintain speed then let off again the EB will not come again. The best luck I have with it is when pulling off the interstate from 80mph I apply the brakes for a second or two and the EB will stay on and transmission will downshift till it cuts off at 20mph. This is with tow/haul on the entire time. The EB doesn't work worth a hill of beans without TH on.

Another thing I just flat don't understand what Ram was thinking about on these trucks, the 68rfe when on cruise will downshift when gaining speed down hills instead of turning the EB on. Makes no sense to me whatsoever. Why downshift when it isn't needed? It will drop TWO gears before it will turn the EB on, when all it really needed to do was turn the EB on in 6th and the truck would have maintained. (I know this because I drive the same mountain pass every day and usually have a trailer so I've tried every configuration of settings possible). Then we mover over to the Aisin, it turns the EB on when descending, great! But it refuses to downshift so with a really heavy load when the EB isn't enough in 6th, I've let it run up to 85mph descending just to see if it would ever downshift, nope. (Again I know this road like the back of my hand, please no lectures about going that fast loaded)

My GMC when descending on cruise will first turn the EB on, then start dropping gears as needed. The speed NEVER exceeds about 4mph over the cruise set point and does it all automatically. It works so well when I come to a corner, I can just tap the speed down 5-10mph and it will apply the EB harder or drop another gear as necessary. Then tap the speed set point back up after the corner. It's a pleasure to drive in the mountains and the twistys, the Rams I'm always trying to manually shift, constantly hitting the brakes, resetting the cruise, etc. If GM can design it to work so well, why can't Ram? With the Capabilities of the Cummins, these trucks should be leading the way in mountain driving, but Ram won't program them so they can.

And why the H E L L do I have to press the gear select button 15 damn times just to finally get it to drop 4 gears??!!

*rant off.

Can't agree more. I'm very frustrated! On my 2002 with my 6 speed and EB I could use it down to zero!
It would seem Chrysler could issue a flash to reprogram easily!!! Or let their engineers drive my rig downhill for me... then they would act!
Tom

 

[Powder Extreme]

Can't agree more. I'm very frustrated! On my 2002 with my 6 speed and EB I could use it down to zero!
It would seem Chrysler could issue a flash to reprogram easily!!! Or let their engineers drive my rig downhill for me... then they would act!
Tom

No kidding!!!! I've often thought, "do the engineers that design these rigs ever DRIVE these rigs?"

 

[Bug Out]

The EB does not work in second gear. The transmission torque converter does not lock in 2nd gear, only 3rd and up. And as far as I know, only 3rd if in TH mode. Maybe someone can chime in if I'm wrong.


Powder Extreme, I inquired about a re-flash last August-sept 2013 after I learned the "flare" in the 68 RFE shift pattern was designed that way.( I'm sure the engineer that designs shift patterns does not drive a RAM)

I was told the process takes some time, Chrysler engineers write a reflash, and every other division it may affect has to test it etc etc. The flare re-flash is apparently at Cummins right now being looked at etc and should be released by the end of August 2014.

Time elapsed, 1 year plus since folks started complaining. I would have thought re-issue the 2012 shift pattern etc.. Nope!!!!!

 

[AH64ID]

The 68RFE will lock in 2nd, just not 1st.

With 3.42s it will be hard to have decent braking in 2nd at 25 at only 1700 rpms. 1st gear would be good below 20 if it locked the converter.

 

[Bug Out]

Mine has never locked in 2nd that I'm aware of. I'll have to listen a little closer when pulling the trailer..

 

[Cummins12V98]

Mine has never locked in 2nd that I'm aware of. I'll have to listen a little closer when pulling the trailer..

Just manually drop it into 2nd and you will see the converter stays locked and EB still works.

 

[tmcIlwain]

Just manually drop it into 2nd and you will see the converter stays locked and EB still works.

OK but what about below 20 mph?

 

[AH64ID]

OK but what about below 20 mph?

Get a manual trans?

It's going to be an issue on anything. 3.42s make it worse, but 4.10s would still have the issue.

 

[Ram4Sam]

Coming from a 2001 six speed with EB wired to a switch on the stick, the Eb on the 2014 auto is way different........I used the my EB all the time on my 01 but never really used it much below 20 mph, below that I just used the brakes. This was with plenty of towing in the mountains. Still learning to drive this new one.........

Sam

 

[gsbrockman]

OK but what about below 20 mph?

Jiminy Cricket!!!!!!!!!!!!

Starting out with the 3rd GEN's, the brakes were so vastly improved......and that carried on over to the 4th GEN's as well.

Do you have so little faith in the service brakes.......and brakes on your trailer......that you NEED engine braking near or below 20 mph??????????

 

[tmcIlwain]

Jiminy Cricket!!!!!!!!!!!!
Starting out with the 3rd GEN's, the brakes were so vastly improved......and that carried on over to the 4th GEN's as well.
Do you have so little faith in the service brakes.......and brakes on your trailer......that you NEED engine braking near or below 20 mph??????????

Well.... no... the service brakes are much improved over my 2002, but in these Colorado mountains with multi-mile downhill's and 15,000 pushing me, I really don't want to smell my brakes at the bottom ;-) I'm not talking about interstate roads, those are much easier, but the many 2 lane mountain pass roads are the concern.
I locked down into 1st 2 days ago coming down out of the Colorado Monument and that wasn't too bad, but then I had no EB help either and not much traffic.

Tom

 

[S.Morris]

The 68RFE will lock in 2nd, just not 1st.

With 3.42s it will be hard to have decent braking in 2nd at 25 at only 1700 rpms. 1st gear would be good below 20 if it locked the converter.

Bingo! the tall gearing is a big part of the problem with what you are trying to do. 4.10's might allow this to work for you if locked up in 2nd. But you can't get that setup factory.........

 

[grabinov]

Does anyone know if it's possible to change axle ratios in these computer controlled trucks? What if you switch to another factory-offerred ratio?

 

[AH64ID]

Does anyone know if it's possible to change axle ratios in these computer controlled trucks? What if you switch to another factory-offerred ratio?

Truck won't care. They don't even use driveshaft rpms for the speedo anymore, just wheel speed sensors.

 

[Newsa]

The exhaust brake engages all the way down to 6 mph on the g56.

 

[Hoefler]

Had the new 14 out with the 5ver last weekend, noticed the Exhaust Brake stayed engaged down to 12 mph.

 

[WalterJ]

I'm not understanding the issue...what are the concerns driving a load downhill above 20mph? Must be some radical terrain for sure.

 

[tmcIlwain]

I'm not understanding the issue...what are the concerns driving a load downhill above 20mph? Must be some radical terrain for sure.

Sure is radical here in Colorado on two lane roads over 12,000 ft mountain passes and down the other side with a 15K trailer pushing you. Many hairpin curves are marked 15 mph or less! Believe it when I say we need to be able to re-engage the EB after using the brakes to slow down for some of these and therein lies the problem as I see it. If all you do is drive interstates then you have no problem.

Tom (original poster)

 

[bigblock_doc]

He seems like he wants an auto pilot. Just steer. Cruise control in the mountains, are you crazy? Sorry about that. What did you do before the
exhaust brake came into production? That's what you are going to do , old school. Be safe out there.

 

[Powder Extreme]

Sure, we don't "need" it. Just like we don't "need" 400hp and a $60,000 rig just to pull our trailer when honestly a 1975 Ford (gasp!) with a 300 straight six would get the job done. But that isn't really the point, is it? The feature is there, we dang sure paid for it, we have the right to expect it to work properly! Too many people just "accept it for what it is" and live with it. That's why the manufacturers all get away with releasing things to market before they are ready.

I completely agree with the original poster, it is nothing short of STUPID how the programmers have the EB set up with the 68rfe. I was in Oregon last week with my 8k boat, made several trips up and down a 10% grade a couple miles long loaded with 15mph corners. My EB will only come on IF the truck is above 32mph. It will then stay on to about 19mph at which point it shuts off due to the RPM's being so low in 2nd (won't engage in 1st). Okay fine, but once the speed is back up above 20mph, it will not turn back on! Why?!? What possible good reason is there for it not to turn back on? I have to accelerate up to 32mph again just to get it to engage again, only to have it drop out at the next corner. Makes absolutely no sense!

When exiting the highway if I am not over 60mph when I let off the throttle, it will not engage. Again WHY?

All of this is in tow haul mode, the brake is useless in regular mode.

/rant off.