Hill Descent Control Limitations

[green02crew]

I tried a long distance hill descent and found after 2 miles, it overheated. The total hill length was 7.5 miles and a drop in elevation of 4,667. I found the traction control would error out after 2 miles. Once it cooled, it would allow activation again. Transmission hit 212* going downhill in 1st.

 

 

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[JimCost2014]

12 minutes ago, green02crew said:

 

I tried a long distance hill descent and found after 2 miles, it overheated. The total hill length was 7.5 miles and a drop in elevation of 4,667. I found the traction control would error out after 2 miles. Once it cooled, it would allow activation again. Transmission hit 212* going downhill in 1st.

 

 

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What model, GMC or Chevy, year of truck?

[green02crew]

What model, make, year of truck?

2018 Sierra with the 6.2


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[JimCost2014]

4 minutes ago, green02crew said:

 

 

2018 Sierra with the 6.2


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Never read the OM about how long you can have it engaged.

 

Thinking it was not designed for that type of distance, how hot did the engine and brakes smell?

[green02crew]

Never read the OM about how long you can have it engaged.
 
Thinking it was not designed for that type of distance, how hot did the engine and brakes smell?

Brakes didn’t smell at all. Engine hit over 220


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[JimCost2014]

16 minutes ago, green02crew said:

 

 

Brakes didn’t smell at all. Engine hit over 220


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I think you now know the exact limitations of the system, good information for the rest of us.

 

I think it is just a "crawl system", short stretches in sketchy situations,  not meant for great distances.

[PMurray]

Am on an Eastern (mountainous) Canada road trip of 3 to 5000 miles with my 14 gmc ext. cab 5.3L, towing an Escape 3400# 5th wheel.  Setting hill decent is spotty and my (navigator) wife can't find anything in the well-worn owner's manual.  Help please on the procedure.

[green02crew]

I think you now know the exact limitations of the system, good information for the rest of us.
 
I think it is just a "crawl system", short stretches in sketchy situations,  not meant for great distances.

I agree. I didn’t think it had limitations. I was quite surprised when it turned off. It did work extremely well until overheating the system (my guess as to what happened). The way up the transmission stayed very cool but the engine ran hot to the point I was worried about overheating. All speeds were done under 20mph up and down.

My biggest surprise was the engine getting very hot on the way up and transmission getting that high on the way down. I didn’t need to hit the brakes even on an 11* downhill slope.

Engine and trans stock, no the max tow package either. That may have made a difference in the results but I don’t think it would have changed the hill descent overuse.


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[green02crew]

Am on an Eastern (mountainous) Canada road trip of 3 to 5000 miles with my 14 gmc ext. cab 5.3L, towing an Escape 3400# 5th wheel.  Setting hill decent is spotty and my (navigator) wife can't find anything in the well-worn owner's manual.  Help please on the procedure.

Hill descent is a button on the center stack, bottom right. Looks like cruise control on a hill. If the button isn’t there, you don’t have it. Only for slow off-road speeds, not highway speeds.


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[JimCost2014]

7 minutes ago, green02crew said:

 

 

I agree. I didn’t think it had limitations. I was quite surprised when it turned off. It did work extremely well until overheating the system (my guess as to what happened). The way up the transmission stayed very cool but the engine ran hot to the point I was worried about overheating. All speeds were done under 20mph up and down.

My biggest surprise was the engine getting very hot on the way up and transmission getting that high on the way down. I didn’t need to hit the brakes even on an 11* downhill slope.

Engine and trans stock, no the max tow package either. That may have made a difference in the results but I don’t think it would have changed the hill descent overuse.


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Does not come with the Max Tow package, which is just an LTZ, not Z71.

[PMurray]

I've got it, but activation has been spotty, probably due to speed.  Thanks!

[JimCost2014]

12 minutes ago, PMurray said:

Am on an Eastern (mountainous) Canada road trip of 3 to 5000 miles with my 14 gmc ext. cab 5.3L, towing an Escape 3400# 5th wheel.  Setting hill decent is spotty and my (navigator) wife can't find anything in the well-worn owner's manual.  Help please on the procedure.

Only comes with the Z71 and Denali packages.

[1SLOW1500]

Let me throw this idea in here what would happen it trans stayed out of the hot trans limp mode?

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