Gear shifter buttons

[Robwcormack]

My gear shifter has plus and minus buttons for what seems like should allow you to manually shift gears.  Problem is, they dont do anything at all when pressed.  Anyone got any ideas of why?

[OnTheReel]

You have to drop the shifter down into “L” before they do anything. When you drop it to L, it will downshift a gear or two (depending on what gear you’re in currently) and then you can go up or down manually from there.

[OnTheReel]

It’s kind of confusing because “L” used to be “M” until 2017 I think. “M” is obviously manual mode but I wouldn’t blame people for not knowing that “L” or low is also manual.

[fish_guru]

The only time I really find myself using it is in the mountains when coasting on a sustained downhill grade I will drop a gear or two and allow the engine to assist in slowing the truck and maintain a safe speed instead of riding the brakes...like downshifting in a manual transmission vehicle to slow it down. 

[Lucely Engineered]

I think L makes more sense anyways because its not a true manual mode. It just keeps the truck from shifting past your set gear. It will still downshift and up shift on its own. 

[DTB]

Slightly off topic but I’ve yet to get an answer. On the older trucks, you could select manual mode and have it in the second highest gear (m5 or m7) and that disables AFM. Does that still work on the new style? 

[Robwcormack]

On 2/27/2019 at 11:22 AM, DTB said:

Slightly off topic but I’ve yet to get an answer. On the older trucks, you could select manual mode and have it in the second highest gear (m5 or m7) and that disables AFM. Does that still work on the new style? 

I'll try tomorrow and see if it affects DFM.  

[Robwcormack]

On 2/27/2019 at 11:22 AM, DTB said:

Slightly off topic but I’ve yet to get an answer. On the older trucks, you could select manual mode and have it in the second highest gear (m5 or m7) and that disables AFM. Does that still work on the new style? 

So, driving set on L7 SEEMS like it might turn the DFM function down if not off.  I can clearly notice the DFM on my truck at 1300 rpm with light throttle.  Feels like a cell phone on vibrate ringing in the center console. I even took it to the dealer to have it checked out because I thought it couldn't possibly by normal.  Of course they told me it was and that I was "essentially feeling a miss-fire".  I am not sure I buy that, but either way when I put it in L7 I don't feel that.  Now I didn't have a long drive, but in D I can make it go in DFM on command.  If it was there with the L7, it was so much more subtle it was undetectable which is the way I understood it should be.  So I won't say without a doubt the DFM function isn't working at all in L7, but if it is I sure can't tell.  What I'm curious of is if maybe it is working but just not dropping as many cylinders so I can't feel it.  Dropping down to 2 or possibly even 1 cylinder (I think I read that) is a bit drastic for a V8.  Personally I want all 8 all the time.  I paid for a V8, so I don't understand why it's not even an option to me whether or not I want to use this function.

[DTB]

Thanks for trying that out. I typically run in m7 myself on my AFM truck to try to prevent lifter damage. I typically don’t run it in m8 unless I’m on the highway and the rpms are high. As soon as the warranty runs up, I will be disabling it all together. 

[bgsntth]

Typically the only time I use the manual shifting is in 4Lo  and climbing grass/gravel slopes or tiptoeing through rocky creeks. I hate the buttons, as I have to take my eyes off the trail to find the toggle buttons. The good news is that the 10-speed transmission is really good offroad and does a great job of being in the right gear for the situation; hence, I do not use manual shifting near as much with prior trucks/SUVs.

[Robwcormack]

On 3/1/2019 at 11:12 AM, bgsntth said:

Typically the only time I use the manual shifting is in 4Lo  and climbing grass/gravel slopes or tiptoeing through rocky creeks. I hate the buttons, as I have to take my eyes off the trail to find the toggle buttons. The good news is that the 10-speed transmission is really good offroad and does a great job of being in the right gear for the situation; hence, I do not use manual shifting near as much with prior trucks/SUVs.

The way it works on mine at least is I set it to L7 and that just prevents it from going to 8th.  It still behaves like it's in D, just doesn't go to 8th

[Cpl_Punishment]

I'm pretty sure I know the answer but, just to confirm, L wouldn't let me shift into second, say if I'm in a low traction situation and want less torque so the wheels don't just spin? 

[Daverado]

3 hours ago, Cpl_Punishment said:

I'm pretty sure I know the answer but, just to confirm, L wouldn't let me shift into second, say if I'm in a low traction situation and want less torque so the wheels don't just spin? 

 

From the manual (page 232):

https://my.gm.ca/content/dam/gmownercenter/gmna/GMCC/dynamic/2019/chevrolet/Silverado/en/19_CHEV_Silverado_OM_en_US_U_23400204A_2018MAY17.pdf

Quote

Low Traction Mode

If equipped, Low Traction Mode assists in vehicle acceleration when road conditions are slippery, such as with ice or snow. While the vehicle is at a stop, select L2 using Range Selection Mode. This will limit torque to the wheels and help prevent the tires from spinning.

 

So it's not really saying specifically what happens when you choose L2, but it's definitely indicating there is an L2 behavior change like in the past.

 

[Sierra Dan]

The same vibration occurs on some K2 trucks between 1500-1900 RPMs.

You can feel it in the floorboard and steering wheel. Not super pronounced but definitely noticeable.

[rikhek]

On 2/24/2019 at 10:25 PM, Robwcormack said:

My gear shifter has plus and minus buttons for what seems like should allow you to manually shift gears.  Problem is, they dont do anything at all when pressed.  Anyone got any ideas of why?

I'm really shocked that this isn't explained in detail in the owner's manual!?!?!?  

Edited March 6, 2019 by rikhek