Auto Start/Stop Feature

[lryfer]

So I am looking at buying a new 2022 GMC Sierra 1500 Limited. On the build sheet it has -50 for Start/Stop feature. Why is this? Are there issues with this feature as I have heard of many GM issues with engines, transmissions etc?

 

Any issues with the 2022 Sierra Limited to be concerned about?

 

Thanks for input.

[CamGTP]

Chip shortage. That is the only reason.

[lryfer]

So with the chip shortage can the truck get he start stop installed with a chip in the future if one wanted to do so? Doesnt that mess up the engine the start stop feature? Just curious.

[HellRazor]

    The Start/Stop feature doesn't mess up the engine per se. But the starter in every vehicle only has so many starts in its lifetime. 
    When you drive to the store, for example, you'll start your vehicle maybe 2 times. 
    If you have the Start/Stop feature activated, your vehicle may shut down and start back up at every stop sign and red light on your way to and from wherever you're going. This constant restarting of your vehicle uses up the available starts your starter has in it's lifetime thus reducing your starters life. 
 

    The feature that supposedly messes up the engine is the Dynamic Fuel Management (DFM). That has been linked to the seized lifters and bent pushrods many V8 Silverado/GMC owners are having. The problem is when some of the cylinders are deactivated during DFM they aren't getting lubricated. So when these cylinders get activated again, after not getting lubricated, they seize up and fail. 

 

As far as I'm concerned, they can take both DFM AND Start/Stop features and stick them in the trash bin of stupid ideas. 

Edited April 10, 2022 by HellRazor

[redwngr]

Fwiw, the starter used on a stop/start truck is not the same one as used on the non stop/start engines.

 

I have no idea if they still use the stop/start starter on the trucks that don't have the chip/module to operate it. 

 

 

There is a long explanaton of the difference in the upfitter docs.

[lryfer]

On 4/10/2022 at 2:27 PM, HellRazor said:

    The Start/Stop feature doesn't mess up the engine per se. But the starter in every vehicle only has so many starts in its lifetime. 
    When you drive to the store, for example, you'll start your vehicle maybe 2 times. 
    If you have the Start/Stop feature activated, your vehicle may shut down and start back up at every stop sign and red light on your way to and from wherever you're going. This constant restarting of your vehicle uses up the available starts your starter has in it's lifetime thus reducing your starters life. 
 

    The feature that supposedly messes up the engine is the Dynamic Fuel Management (DFM). That has been linked to the seized lifters and bent pushrods many V8 Silverado/GMC owners are having. The problem is when some of the cylinders are deactivated during DFM they aren't getting lubricated. So when these cylinders get activated again, after not getting lubricated, they seize up and fail. 

 

As far as I'm concerned, they can take both DFM AND Start/Stop features and stick them in the trash bin of stupid ideas. 

So can you turn off the DFM and run just like the straight 8 per say or stuck with it? I just bought a 2022 Sierra 1500 limited with the DFM installed. Picking up saturday

 

[energyman2005]

My new AT4 has the auto stop/start feature.  In three weeks of owning the truck, it is turned off maybe 4 times in total at stoplights.  So it doesn't even work as intended...

[Dirk13]

1 hour ago, energyman2005 said:

My new AT4 has the auto stop/start feature.  In three weeks of owning the truck, it is turned off maybe 4 times in total at stoplights.  So it doesn't even work as intended...

It is not intended to go into auto stop at every single stop. There are many different criteria that the truck uses to determine whether or not it can turn itself off.

 

Trucks not warmed up? Won’t shut off.  Blasting ac? Won’t shut off. 
Something using a high amount of power? Won’t shut off.

and so on

[Acpantera]

On 4/22/2022 at 11:16 AM, redwngr said:

Fwiw, the starter used on a stop/start truck is not the same one as used on the non stop/start engines.

 

I have no idea if they still use the stop/start starter on the trucks that don't have the chip/module to operate it. 

 

 

There is a long explanaton of the difference in the upfitter docs.

The Battery is also upgraded to an AGM in the auto stop/start featured vehicles, well worth 50 bucks

[energyman2005]

On 6/2/2022 at 6:47 PM, Dirk13 said:

It is not intended to go into auto stop at every single stop. There are many different criteria that the truck uses to determine whether or not it can turn itself off.

 

Trucks not warmed up? Won’t shut off.  Blasting ac? Won’t shut off. 
Something using a high amount of power? Won’t shut off.

and so on

Good to know!!  

[redwngr]

Owners manual lists a bunch of the reasons:

 

Auto Stops may not occur and/or Auto Starts may occur because:

. The climate control settings require the engine to be running to cool or heat the vehicle interior.
. The vehicle battery charge is low.
. The vehicle battery has recently been disconnected.
. Minimum vehicle speed has not been reached since the last Auto Stop.
. The accelerator pedal is pressed.
. The engine or transmission is not at the required operating temperature.
. The outside temperature is not in the required operating range.
. The vehicle is in any gear other than D (Drive).
. Tow/Haul Mode or other driver modes have been selected.
. The vehicle is on a steep hill or grade.
. The driver door has been opened or the driver seat belt has been unbuckled.
. The hood has been opened.

. The Auto Stop has reached the maximum allowed time.

 

The automatic engine Stop/Start feature can be disabled and enabled by pressing [stop/start] switch.

Auto Stop/Start is enabled each time you start the vehicle.
When the switch indicator is illuminated, the system is enabled.