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2011 Tow / Haul Mode.

RJG183SA

By RJG183SA
in 2000-2014 Silverado HD & Sierra HD

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RJG183SA Enthusiast

RJG183SA

Posted
Posted

Has GM changed the tow / haul mode trans. programming on 2011 models?

 

Pulled my trailer for the first time yesterday. With tow / haul engaged, there was no aggressive down shifting. Reminds me of my 03, no trans. braking.

 

My previous 09 produced very aggressive down shifts with tow / haul active.

 

Anybody with a 2011 model that can verify this?

Stevens03 Senior Enthusiast

Stevens03

Posted
Posted

Mines a little less than before but that was 4-speed to 6-speed. I just thought that was the nature of the 6-speed :dunno:

djmercer1 Enthusiast

djmercer1

Posted
Posted
Has GM changed the tow / haul mode trans. programming on 2011 models?

 

Pulled my trailer for the first time yesterday. With tow / haul engaged, there was no aggressive down shifting. Reminds me of my 03, no trans. braking.

 

My previous 09 produced very aggressive down shifts with tow / haul active.

 

Anybody with a 2011 model that can verify this?

 

diesle or gas? more info please...

ChevyTech77 Senior Enthusiast

ChevyTech77

Posted
Posted

Taken straight from the '11 owners manual............

 

"Grade Braking is only active while

the Tow/Haul Mode is selected and

 

 

 

you are not in the Range Selection

 

 

 

Mode. See “Tow/Haul Mode” listed

 

 

 

previously and Manual Mode on

 

 

 

page 9‑50 for more information

 

 

on the Range Selection Mode.

 

RJG183SA Enthusiast

RJG183SA

Posted
  • Author
Posted
Has GM changed the tow / haul mode trans. programming on 2011 models?

 

Pulled my trailer for the first time yesterday. With tow / haul engaged, there was no aggressive down shifting. Reminds me of my 03, no trans. braking.

 

My previous 09 produced very aggressive down shifts with tow / haul active.

 

Anybody with a 2011 model that can verify this?

 

diesle or gas? more info please...

 

 

Sorry, gas.

 

 

Taken straight from the '11 owners manual............

 

"Grade Braking is only active while

the Tow/Haul Mode is selected and

 

 

 

you are not in the Range Selection

 

 

 

Mode. See “Tow/Haul Mode” listed

 

 

 

previously and Manual Mode on

 

 

 

page 9‑50 for more information

 

 

on the Range Selection Mode.

 

 

Tow / Haul only. Manual mode NOT selected.

 

As I said previously, my 09 2500 HD, gasser, down shifted very aggressively. The engine would rev up, then you would feel it go into the lower gear.

 

I tried it out again today. Same thing. Honestly I can't feel it down shift at all it is so subtle, regardless of how hard I apply the brakes.

ChevyTech77 Senior Enthusiast

ChevyTech77

Posted
Posted
Tow / Haul only. Manual mode NOT selected.

 

As I said previously, my 09 2500 HD, gasser, down shifted very aggressively. The engine would rev up, then you would feel it go into the lower gear.

 

I tried it out again today. Same thing. Honestly I can't feel it down shift at all it is so subtle, regardless of how hard I apply the brakes.

Silly question, are you towing anything when this is not happening?

 

As for if there is a difference between '09 and '11 trans controller programming? Yes, I am quite sure there is however, I would bet that grade braking will work in your '11, in tow/haul mode, when you're towing. I know it works in my '11 1500 6.2.

RJG183SA Enthusiast

RJG183SA

Posted
  • Author
Posted
Tow / Haul only. Manual mode NOT selected.

 

As I said previously, my 09 2500 HD, gasser, down shifted very aggressively. The engine would rev up, then you would feel it go into the lower gear.

 

I tried it out again today. Same thing. Honestly I can't feel it down shift at all it is so subtle, regardless of how hard I apply the brakes.

Silly question, are you towing anything when this is not happening?

 

As for if there is a difference between '09 and '11 trans controller programming? Yes, I am quite sure there is however, I would bet that grade braking will work in your '11, in tow/haul mode, when you're towing. I know it works in my '11 1500 6.2.

 

 

Yes, I'm towing. Same trailer, same weight. Tow / Haul "ON". No aggressive down shifting.

 

I remember with my 09, it would down shift aggressively regardless of going down a grade or not.

ChevyTech77 Senior Enthusiast

ChevyTech77

Posted
Posted
Yes, I'm towing. Same trailer, same weight. Tow / Haul "ON". No aggressive down shifting.

 

I remember with my 09, it would down shift aggressively regardless of going down a grade or not.

Another silly question, your '09 wasn't a diesel, was it?

 

Checked mine again last night and yup, mine works. Even in manual mode with tow/haul on. Might be some

sort of cal swap issue going on there or something.

RJG183SA Enthusiast

RJG183SA

Posted
  • Author
Posted
Yes, I'm towing. Same trailer, same weight. Tow / Haul "ON". No aggressive down shifting.

 

I remember with my 09, it would down shift aggressively regardless of going down a grade or not.

Another silly question, your '09 wasn't a diesel, was it?

 

Checked mine again last night and yup, mine works. Even in manual mode with tow/haul on. Might be some

sort of cal swap issue going on there or something.

 

 

09 gas also. Looks like a trip to service is in order. :dunno:

ChevyTech77 Senior Enthusiast

ChevyTech77

Posted
Posted
09 gas also. Looks like a trip to service is in order. :dunno:

 

Make sure, that during the service write up, the concern you have is worded, "Grade braking is inoperative." Take the shop foreman or service manager out with you on a quick test drive to show them as well.

TorkFaze Enthusiast

TorkFaze

Posted
Posted
Tow / Haul only. Manual mode NOT selected.

 

As I said previously, my 09 2500 HD, gasser, down shifted very aggressively. The engine would rev up, then you would feel it go into the lower gear.

 

I tried it out again today. Same thing. Honestly I can't feel it down shift at all it is so subtle, regardless of how hard I apply the brakes.

Silly question, are you towing anything when this is not happening?

 

As for if there is a difference between '09 and '11 trans controller programming? Yes, I am quite sure there is however, I would bet that grade braking will work in your '11, in tow/haul mode, when you're towing. I know it works in my '11 1500 6.2.

 

 

Yes, I'm towing. Same trailer, same weight. Tow / Haul "ON". No aggressive down shifting.

 

I remember with my 09, it would down shift aggressively regardless of going down a grade or not.

 

 

 

 

Are you saying the trans doesn't do any gradebraking downshifts, or that the shifts aren't as 'aggressive' in feel?? The timing of the gradebraking shifts are similar (but not identical) between 2009 and 2011, but the shift FEEL was worked on to make it somewhat more refined in 2011.

RJG183SA Enthusiast

RJG183SA

Posted
  • Author
Posted
Are you saying the trans doesn't do any gradebraking downshifts, or that the shifts aren't as 'aggressive' in feel?? The timing of the gradebraking shifts are similar (but not identical) between 2009 and 2011, but the shift FEEL was worked on to make it somewhat more refined in 2011.

 

The downshifts feel the same. Tow / Haul active or not active. I can't feel or hear the downshifts. Watching the tach during decel there is no rpm increase when the next lower gear is engaged. This was definately not the way my 09 performed.

 

When using "range selection mode", Tow / Haul not active, the rpm's increase upon selecting a lower gear.

 

I'll be calling the dealer soon. Just been to busy with other matters.

  • 3 weeks later...
RJG183SA Enthusiast

RJG183SA

Posted
  • Author
Posted

UPDATE .......

 

Finally got a chance to get to the dealer today. Spoke to the service writer. Explained to him the "grade braking" differences between my previous '09 and current '11. He could not offer me anything definitive. Only to say in his words, "sometimes they make little changes and we never hear about it". He never offered to take it for a test drive, nor did I ask.

 

With the help of my salesman, I was able to take a 2012 model for a short ride. It performed similar to my '11 model with tow / haul active. Seems to be performing as designed.

 

On a side note and not to be confused with my original questions, while discussing the issue the fleet manager brought me into his office and showed me an online brochure that specifically stated that "grade braking" is always active, tow / haul active or not. This directly contradicts what my owners manual says, pg. 9-51. I didn't happen to notice which model year the info reffered to.

 

Perhaps TorkFaze will chime and clarify.

Portdriver Enthusiast

Portdriver

Posted
Posted

I can feel a slight downshift in tow/haul mode. Grade braking is always active on my 2011.

TorkFaze Enthusiast

TorkFaze

Posted
Posted
UPDATE .......

 

Finally got a chance to get to the dealer today. Spoke to the service writer. Explained to him the "grade braking" differences between my previous '09 and current '11. He could not offer me anything definitive. Only to say in his words, "sometimes they make little changes and we never hear about it". He never offered to take it for a test drive, nor did I ask.

 

With the help of my salesman, I was able to take a 2012 model for a short ride. It performed similar to my '11 model with tow / haul active. Seems to be performing as designed.

 

On a side note and not to be confused with my original questions, while discussing the issue the fleet manager brought me into his office and showed me an online brochure that specifically stated that "grade braking" is always active, tow / haul active or not. This directly contradicts what my owners manual says, pg. 9-51. I didn't happen to notice which model year the info reffered to.

 

Perhaps TorkFaze will chime and clarify.

 

 

 

GM's full size trucks with gas motors and 6-speeds have never had Grade Braking (foot on brake) downshifts available unless you're in Tow-Haul. The exception is that the 2012 trucks get Grade braking in CRUISE without being in T/Haul to try to help maintain your set speed somewhat. In 2009-2011 gas motor 6-speed trucks, grade braking in Cruise (and grade braking with foot on brake) was only available in T/Haul.

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