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DFM/AFM dropped from some 2021 GM trucks?

johnny Ainsworth
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johnny Ainsworth New Member

johnny Ainsworth

Posted
Posted

I read read in an article that in May 2021, GM dropped the DFM/AFM from some of its pickups with the 5.3l engine.  Was told to look for RPO code, YK9 to determine if it was made without the DFM/AFM.  Does anyone know if GM is still making engines without the DFM/AFM?  I'm really wanting the 6.2L, but would consider the 5.3L if I can get it without the DFM/AFM.  As a side note, did GM just not chip for the DFM/AFM but left all the internal components the same? 

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KARNUT Senior Enthusiast

KARNUT

Posted
Posted (edited)
15 minutes ago, johnny Ainsworth said:

I read read in an article that in May 2021, GM dropped the DFM/AFM from some of its pickups with the 5.3l engine.  Was told to look for RPO code, YK9 to determine if it was made without the DFM/AFM.  Does anyone know if GM is still making engines without the DFM/AFM?  I'm really wanting the 6.2L, but would consider the 5.3L if I can get it without the DFM/AFM.  As a side note, did GM just not chip for the DFM/AFM but left all the internal components the same? 

I read guts no chip. And they rebate 50$ for the 1-2 mile decrease in fuel mileage.

Edited by KARNUT
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Enough Enthusiast

Enough

Posted
Posted

But you still have all of the failure prone parts installed in your engine without the chip to enable them, and no option to add the chip. That $50.00 rebate is a slap in the face as far as I am concerned.

2016 Sierra Owner Senior Enthusiast

2016 Sierra Owner

Posted
Posted

The internal engine parts stayed the same (DFM lifters and control valves). The controls that activate the DFM were not installed due to the chip shortage. As stated above this feature will not be retrofitted by GM either.

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Z45 Senior Enthusiast

Z45

Posted
Posted (edited)

fyi

Don't know if this a fact but I read somewhere the ECM for DFM/AFM uses many chips. Most think 1 chip but its an array of chips that control DFM. 

The New York Times NYT -0.9% said that a modern vehicle can use as many as 3,000 semiconductor chips, while another source said over 1000.

 

Quote

While diagnosing engine or electrical wiring concerns on these models, keep in mind that internal components related to AFM or DFM functions will be present in the engines as well as related wiring, connectors and fuses. The Engine Control Module (ECM) will not be capable of activating the cylinder deactivation technology.

When diagnosing and repairing concerns regarding engine or electrical functions that may be related to AFM- or DFM-related hardware, follow the diagnostics in the appropriate Service Information. No changes have been made to AFM- or DFM-related components.

For additional information, refer to #21-NA-078.

 

 

Edited by elcamino
Black02Silverado Senior Enthusiast

Black02Silverado

Posted
Posted

My take is GM isn't going to spend the extra cost to build specific engines for those that don't have DFM .  They have a huge supply of DFM parts that will go in the engine and just no electronics to control/turn on the DFM.  It would cost more to pick and choose as opposed to just keep things the same down the assembly line and just not have the option active.

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Amcguy1970 Enthusiast

Amcguy1970

Posted
Posted

It is amazing this could have been a google search or GM-trucks search as opposed to a post. This has been discussed a ton. As others have said, all the internals are there, it just won't activate. Same as plugging in a range device really. 

 

Tyler

  • Like 2
Black02Silverado Senior Enthusiast

Black02Silverado

Posted
Posted
3 hours ago, Amcguy1970 said:

It is amazing this could have been a google search or GM-trucks search as opposed to a post. This has been discussed a ton. As others have said, all the internals are there, it just won't activate. Same as plugging in a range device really. 

 

Tyler

I just drive in L9.  Keeps it from going into DFM and auto stop.  I do mostly in town driving anyway so not like I need all the gears.

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customboss Senior Enthusiast

customboss

Posted
Posted
4 hours ago, Black02Silverado said:

I just drive in L9.  Keeps it from going into DFM and auto stop.  I do mostly in town driving anyway so not like I need all the gears.

You’re latest oil analysis was best ever using this technique. 

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Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted (edited)
9 hours ago, customboss said:

You’re latest oil analysis was best ever using this technique. 

 

And you believe that this correlation is causation? 

 

I wore a blue shirt today and it rained. Was it the cause? :dunno:

 

 

Edited by Grumpy Bear
  • Haha 1
KARNUT Senior Enthusiast

KARNUT

Posted
Posted
16 hours ago, Black02Silverado said:

I just drive in L9.  Keeps it from going into DFM and auto stop.  I do mostly in town driving anyway so not like I need all the gears.

My father in law’s CRV has auto stop. It’s not smooth by any stretch. While driving him around checking out assisted living I hit the button to shut the feature off. He noticed and appreciated that I showed him. I don’t know if the CRV has cylinder deactivation. His Honda mini van did. It started shaking and using oil he says. The reason he’s driving a CRV. Come to think of it my daughter just made her last payment on her Honda mini van. It’s just passed the mileage my father in law’s failed, joy. If Honda has issues. The rest are toast. Probably why Toyota doesn’t have cylinder deactivation or electric cars either. 

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customboss Senior Enthusiast

customboss

Posted
Posted
4 hours ago, Grumpy Bear said:

 

And you believe that this correlation is causation? 

 

I wore a blue shirt today and it rained. Was it the cause? :dunno:

 

 

No, didn’t say that. But it’s the only change Nick says he did. Look at the wear control improvements with poor nitration control   

 

  • Confused 1
customboss Senior Enthusiast

customboss

Posted
Posted
1 hour ago, KARNUT said:

My father in law’s CRV has auto stop. It’s not smooth by any stretch. While driving him around checking out assisted living I hit the button to shut the feature off. He noticed and appreciated that I showed him. I don’t know if the CRV has cylinder deactivation. His Honda mini van did. It started shaking and using oil he says. The reason he’s driving a CRV. Come to think of it my daughter just made her last payment on her Honda mini van. It’s just passed the mileage my father in law’s failed, joy. If Honda has issues. The rest are toast. Probably why Toyota doesn’t have cylinder deactivation or electric cars either. 

Honda has had many problems. It’s not the Honda quality we all remember. Sadly. 

  • Thanks 1
Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted
1 hour ago, customboss said:

No, didn’t say that. But it’s the only change Nick says he did. Look at the wear control improvements with poor nitration control   

 

What I see is a motor bedding in nicely. Wear is declining per unit miles OCI on a very nice graphable track. His fuel dilution and water declining with miles as the rings play nicer with the cylinder. Nitration has been floating around since the first sample but fairly stable the last three samples.  It's also absent the new oil FTIR references so I wouldn't know what to make of that. He has also used various oils making apples to apples pretty hard without those references. 11/12 nitration on an oil with a background of 4 is quite a different number than an oil with a background of 7 or 8. 

 

If I know Nick, that man is all up in the maintenance grill of his pet ride. :D 

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