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2016 Silverado 5.3 6 speed lunging upon decel

nluchau

By nluchau
in Troubleshooting & Recalls

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nluchau Enthusiast

nluchau

Posted
Posted

Just turned 13k on my 2016 Silverado 5.3 with a 6 speed. This has happened since day 1 but wondering if its a "feature" on this one. If I am going 60 on interstate and let off the gas to coast into an off ramp I can often times feel a lunge sensation. Not sure if this is the TC releasing or what it may be. This also happens during in town driving coasting down from 40. I don't believe this is the downshift as I feel all of those from 40, 30, 20 and almost stopped.

 

Hope this makes sense.

Sierra706 Senior Enthusiast

Sierra706

Posted
Posted

I've noticed this in a loaner silverado the dealership gave me. I could also feel the torque converter lock up under acceleration. I can't feel it in my truck, but I believe it's due to having either factory 22's or my 17s with ridge grapplers. The loaner truck had tiny little stock sofa casters for wheels and the truck behaved noticeably different.

 

 

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nluchau Enthusiast

nluchau

Posted
  • Author
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I've noticed this in a loaner silverado the dealership gave me. I could also feel the torque converter lock up under acceleration. I can't feel it in my truck, but I believe it's due to having either factory 22's or my 17s with ridge grapplers. The loaner truck had tiny little stock sofa casters for wheels and the truck behaved noticeably different.

 

 

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Mine is completely stock.

sk Senior Enthusiast

sk

Posted
Posted

It's the Grade Braking feature kicking in. The TCM is programmed to do that when you let off the accelerator since it thinks you are slowing down (instead of using your service brakes and wearing out the pads). Try turning off Grade Braking and see if it makes a difference (hold in the Tow/Haul button for 5-10 seconds and you should get a message on the DIC that it's disabled).

 

The only bad part is that it resets each time the ignition is turned off so if it helps you need to do it each time you start the truck.

chrispassas21 Enthusiast

chrispassas21

Posted
Posted

Mine also does this. 24k miles stock 18's with good year duratracs

 

 

2015 1500 LT Silverado Midnight Edition

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nluchau Enthusiast

nluchau

Posted
  • Author
Posted

It's the Grade Braking feature kicking in. The TCM is programmed to do that when you let off the accelerator since it thinks you are slowing down (instead of using your service brakes and wearing out the pads). Try turning off Grade Braking and see if it makes a difference (hold in the Tow/Haul button for 5-10 seconds and you should get a message on the DIC that it's disabled).

 

The only bad part is that it resets each time the ignition is turned off so if it helps you need to do it each time you start the truck.

If it was grade braking it would say "Grade Braking active" on the display though which it isn't. I can count on one hand how many times I've seen that message pop up. You can watch your dog run away for 7 days here in ND.

sk Senior Enthusiast

sk

Posted
Posted

If it was grade braking it would say "Grade Braking active" on the display though which it isn't. I can count on one hand how many times I've seen that message pop up. You can watch your dog run away for 7 days here in ND.

 

The message does not come on the DIC during some operations like level driving and it only displays the first time Grade Braking is applied. From Owners Manual Page 5-44:

 

GRADE BRAKING ACTIVE
This message displays when grade braking has been activated while driving on downhill grades. This message will only appear the first time the feature is activated in an ignition cycle.

 

 

Also there are 2 styles of grade braking. From the manual:

Normal Mode Grade Braking
If equipped with a gasoline engine and an automatic transmission, Normal Mode Grade Braking is enabled when the vehicle is started, but is not enabled in Range Selection Mode. It assists in maintaining desired vehicle speeds when driving on downhill grades by using the engine and transmission to slow the vehicle. The first time the system engages for each ignition key cycle, a DIC message will be displayed.
Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is only enabled while the Tow/Haul Mode is selected and the vehicle is not in the Range Selection Mode. Tow/Haul Mode Grade Braking assists in maintaining desired vehicle speeds when driving on downhill grades by using the engine and transmission to slow the vehicle.
nluchau Enthusiast

nluchau

Posted
  • Author
Posted

 

 

The message does not come on the DIC during some operations like level driving and it only displays the first time Grade Braking is applied. From Owners Manual Page 5-44:

 

GRADE BRAKING ACTIVE
This message displays when grade braking has been activated while driving on downhill grades. This message will only appear the first time the feature is activated in an ignition cycle.

 

 

Also there are 2 styles of grade braking. From the manual:

Normal Mode Grade Braking
If equipped with a gasoline engine and an automatic transmission, Normal Mode Grade Braking is enabled when the vehicle is started, but is not enabled in Range Selection Mode. It assists in maintaining desired vehicle speeds when driving on downhill grades by using the engine and transmission to slow the vehicle. The first time the system engages for each ignition key cycle, a DIC message will be displayed.
Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is only enabled while the Tow/Haul Mode is selected and the vehicle is not in the Range Selection Mode. Tow/Haul Mode Grade Braking assists in maintaining desired vehicle speeds when driving on downhill grades by using the engine and transmission to slow the vehicle.

 

It's not a braking sensation I am feeling though. It's a surge or lunge which almost feels like the torque converter is releasing or something of that nature. It happens in drive and manual mode.

nluchau Enthusiast

nluchau

Posted
  • Author
Posted

I feel it in my 3/4 ton. It's the trans downshifting I believe

Thanks for chiming in Buckshot! I appreciate your input. Seems to really happen when I step on it and let off and coast a bit. I can feel the lunge.

KARNUT Senior Enthusiast

KARNUT

Posted
Posted

If you mean lunge ahead, the only time I ever felt that is if your accelerating in a lower gear and let off it will shift up a gear then slow down. I experience it a lot when I was test driving cvt equipped vehicles and some regular transmission.

  • 3 months later...
nluchau Enthusiast

nluchau

Posted
  • Author
Posted

Can I revive this again?  

 

So my truck is still doing it, when coasting to a stop from lets say 40 at about 20 or so I can feel this release that pushes the truck forward like a lunge or surge.  Is this the torque converter releasing and if so is this normal to feel this so much?  

Also I still have the jerky downshifts when slowing down, happens at about 40mph, 30mph, 20 mph and almost stopped.  

chrispassas21 Enthusiast

chrispassas21

Posted
Posted
I sort of feel I am one of the very few experiencing this. 

You are not the only one! I am going to the dealership tomorrow and will ask if they will do a “re-learn” on the transmission for me.


2015 Silverado LT Midnight Edition
4.5” CST suspension lift
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Thomcat Senior Enthusiast

Thomcat

Posted
Posted
On 8/23/2017 at 3:36 PM, sk said:

 

The message does not come on the DIC during some operations like level driving and it only displays the first time Grade Braking is applied. From Owners Manual Page 5-44:

 

GRADE BRAKING ACTIVE
This message displays when grade braking has been activated while driving on downhill grades. This message will only appear the first time the feature is activated in an ignition cycle.

 

 

Also there are 2 styles of grade braking. From the manual:

 
Normal Mode Grade Braking
If equipped with a gasoline engine and an automatic transmission, Normal Mode Grade Braking is enabled when the vehicle is started, but is not enabled in Range Selection Mode. It assists in maintaining desired vehicle speeds when driving on downhill grades by using the engine and transmission to slow the vehicle. The first time the system engages for each ignition key cycle, a DIC message will be displayed.
 
Tow/Haul Mode Grade Braking
Tow/Haul Mode Grade Braking is only enabled while the Tow/Haul Mode is selected and the vehicle is not in the Range Selection Mode. Tow/Haul Mode Grade Braking assists in maintaining desired vehicle speeds when driving on downhill grades by using the engine and transmission to slow the vehicle.

Z71's contain an additional grade braking control that acts like a slow speed cruise control controlling gearing with automatic braking to prevent a runaway condition on a steep downgrade.

 

Hill Descent
Control (HDC)
If equipped, HDC can be used when
driving downhill. It sets and
maintains vehicle speed while
descending a very steep incline in a
forward or reverse gear.
The HDC switch is on the center
stack, below the climate controls.
Press 5 to enable or disable HDC.
Vehicle speed must be below
50 km/h (31 mph).
The HDC light displays on the
instrument cluster when enabled.
HDC can maintain vehicle speeds
between 3 and 22 km/h (2 and
14 mph) on an incline greater than
or equal to a 10% grade. A blinking
HDC light indicates the system is
actively applying the brakes

 

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