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I'm not sure my exhaust brake works, I have been messing with it from day one and have never felt it work, I push down the switch and my little trailer light thingy comes on the dash but nothing seams to be happening
 

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It's only used in grade braking and If you're heavy footed, you'll never feel it. But, if you have any steep down hills near you get rolling down it and push the brake pedal for a sec and then the exhaust brake kick in. You pretty much tell it what speed you want with the brake pedal on a downhill

Also, doesn't really matter how steep the road is, the exhaust brake will keep you at that speed even pulling a load
 

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Oh OK well shitbalz.................I guess I didn't know about the brake pedal to activate it, we have plenty of steep mountain passes I will give it a whirl
 
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Put a trailer on behind you with even a little weight and you'll notice it working and holding you back. I try my best not to use my brakes a lot with it on because then the transmission down shifts almost immediately and revs the engine up to like 3-4000 rpm's. Seems kind of excessive.
 

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Put a trailer on behind you with even a little weight and you'll notice it working and holding you back. I try my best not to use my brakes a lot with it on because then the transmission down shifts almost immediately and revs the engine up to like 3-4000 rpm's. Seems kind of excessive.
Mine does that whether I'm towing or not and if the exhaust brake is on or not. Annoys the piss out me.
 

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Hmm.

When I have the exhaust brake/tow haul mode on and I tap the brakes on a downhill it will shift down a little and hold speed with the exhaust brake (closes off the variable vanes on the turbo) and if I have to push the brakes again, it'll downshift again producing more rpms and more exhaust braking effect.

Basically it will downshift more the longer or the more I push the brakes, but only with tow haul/exhaust brake on
 

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Put a trailer on behind you with even a little weight and you'll notice it working and holding you back. I try my best not to use my brakes a lot with it on because then the transmission down shifts almost immediately and revs the engine up to like 3-4000 rpm's. Seems kind of excessive.
Have you tried just tapping the brakes and letting it work? If you hold the brakes longer it downshifts more because it thinks you want a whole lot of engine braking. At least that's what my truck does.
 

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Gotcha. I'll have to give that a try. I was coming into an off ramp and just held on the brakes and it was like whoaaaaaa. I'll have to try tapping it next time and see what it does instead of pressing and holding.

About what Sappergod said though, of his always doing it. It sounds like his may be stuck in tow/ haul all the time then? That's no good...
 

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There is a sweet spot of about a second. If you just give it a tap, not much happens. But if you hold it for too long it gets a little overzealous.

Also, this just came to mind, I know these transmissions "learn" so, that may have something to do with different peoples acting differently.
 

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There is a sweet spot of about a second. If you just give it a tap, not much happens. But if you hold it for too long it gets a little overzealous.

Also, this just came to mind, I know these transmissions "learn" so, that may have something to do with different peoples acting differently.
Mine shouldn't still be learning with over 26k miles in 13 months......
 

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Mine shouldn't still be learning with over 26k miles in 13 months......
I agree with you, I wasn't specifically referencing your truck. But, if you were to drive more aggressively than someone else, your truck would shift differently. Still not saying that's the case with your truck, just a "what if". personally I think your truck is broken.

My tundra was the first learning auto I ever had, and I drove the pee out of that truck most of the time. If I ever drove like a paw paw it would feel like total crap because of how it learned.

They have quick learn and slow learn. After a reset or a reflash they're in quick learn. After you've settled in, it's slow learn.
 

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From page 46 of the duramax supplemental manual. Referencing downshifts vs how long you hold brakes

"Downshifts may be automatically
selected to increase engine speed,
which increases the effectiveness of
the exhaust brake. The number of
downshifts selected is determined
by the length of time the brakes are
applied and the rate the vehicle is
slowing. The system delivers the
correct amount of braking to assist
in vehicle control. The heavier the
vehicle load, the more active the
engine exhaust brake will be. Use of
the exhaust brake will help maintain
vehicle speed when used with
cruise control. See Cruise Control
in the owner manual."
 

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I can definitely confirm that towed load makes a difference. When I "tested" the exhaust brake a few times just driving around I thought it was "cute"... Which doesn't mean effective or impressive. However, when I had to tow my friend's 6500 lb trailer home for him, it was definitely active and it made quite a difference... it was also quite a bit louder than when I was trying it with no trailer.
 

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I just want to point out that even when im not in tow mode but going down a hill my exhaust brake kicks on when tapping the brakes.
The tow mode doesnt need to be on.
 

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I was dissapointed that it dosent sound like a semi jake brake, mine just goes blub blub blub blub til its slowed me down. It works though
 

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I'm not sure my exhaust brake works, I have been messing with it from day one and have never felt it work, I push down the switch and my little trailer light thingy comes on the dash but nothing seams to be happening
I personally hate this exhaust brake idea.
It does very little beside reving the **** out of the motor. I think it is a total wast of wear and tear on the motor.

I don’t want my diesel reving to 4K on a small brake application. It’s just stupid.
I have multiple trailers and even with my little utility trailer there is no noticeable speed reduction just a lot of diesel noise. I have tried this multiple times and always end up turning off tow mode when slowing for an exit off the hwy.
And if I can’t tell any difference with my little utility trailer I am damn sure it’s not going to be of any value slowing my RV.....
Even without a trailer taking the same exit as always coming home from work, turning on trailer tow and having the diesel motor rev it’s ass off makes little to no difference in the amount of brake pedal pressure I need to slow the truck for the downhill exit ramp. It’s just to small of a motor to make any useful difference.

Rob
 

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I have no problem noticing the exhaust brake on my truck and helping me stop. I mean, sometimes it does rev higher, but if it doesn’t rev higher, it doesn’t work, not enough pressure against the turbo gets built.

Also though, now that I have tuned my truck, tow/ haul seems to not be as aggressive, but it still stops my truck with my 12x6 utility trailer. Just my opinion but I like the feature :)
 
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