Does my truck have DFM?

[Nestor Romero]

I have  2021 Silverado LTZ 5.3L the sticker does not say that it has DFM.

 

it does have auto stop but i think that may be irrelevant.

 

does this mean I got lucky and do not have DFM?

[JimCost2014]

34 minutes ago, Nestor Romero said:

I have  2021 Silverado LTZ 5.3L the sticker does not say that it has DFM.

 

it does have auto stop but i think that may be irrelevant.

 

does this mean I got lucky and do not have DFM?

It will have YK9 RPO code if DFM is deleted.

[Enough]

My understanding from other posts on this forum is that even if you got "lucky" and don't have DFM your engine still has the same internal components that mine with DFM has. You just don't have the chip to activate them and should have gotten a whopping $50.00 discount off of MSRP.

 

The jury is still out about your chances of your truck having the same lifter failure my truck might have.

 

26,733 miles and counting on mine......

[2018GMC]

7 hours ago, Enough said:

My understanding from other posts on this forum is that even if you got "lucky" and don't have DFM your engine still has the same internal components that mine with DFM has. You just don't have the chip to activate them and should have gotten a whopping $50.00 discount off of MSRP.

 

The jury is still out about your chances of your truck having the same lifter failure my truck might have.

 

26,733 miles and counting on mine......

True. Due to the semiconductor chip shortage, this affects options like DFM, heated seats, rearview camera mirror, etc. You still have all the physical hardware for DFM but the computer chips are missing to activate it.

[redwngr]

 

For 2021 LTZ

 

 

L84         Engine, 5.3L EcoTec3 V8, (355 hp [265 kW] @ 5600 rpm, 383 lb-ft of torque [518 Nm] @ 4100 rpm); featuring available Dynamic Fuel Management that enables the engine to operate in 17 different patterns between 2 and 8 cylinders, depending on demand, to optimize power delivery and efficiency
1 -  NOTE: Certain 21MY vehicles will include (YK9) Not Equipped with Dynamic Fuel Management. 

 

YK9    Not Equipped with Dynamic Fuel Management
1 -  Included and only available with (L84) 5.3L EcoTec3 V8 engine. 

 

If it was a HC with L84, then

YK9  -  Included and only available with 2WD model, (L84) 5.3L EcoTec3 V8 engine and (MQE) 8-speed automatic transmission.

[Nestor Romero]

On 3/8/2022 at 7:48 PM, JimCost2014 said:

It will have YK9 RPO code if DFM is deleted.

On the window sticker?

[Nestor Romero]

On 3/8/2022 at 11:07 PM, Enough said:

My understanding from other posts on this forum is that even if you got "lucky" and don't have DFM your engine still has the same internal components that mine with DFM has. You just don't have the chip to activate them and should have gotten a whopping $50.00 discount off of MSRP.

 

The jury is still out about your chances of your truck having the same lifter failure my truck might have.

 

26,733 miles and counting on mine......

I see, but the actual DFM feature is the one that allegedly causes the lifter failure correct? So if thats correct it would be fair to say that a truck without DFM would have less chances of experiencing lifter failures.

[voided3]

6 hours ago, Nestor Romero said:

I see, but the actual DFM feature is the one that allegedly causes the lifter failure correct? So if thats correct it would be fair to say that a truck without DFM would have less chances of experiencing lifter failures.

The lifters themselves are the failure prone component due to design, but in recent history they also had a bad batch with a manufacturing defect (our truck included). It's believed that disabling DFM/AFM reduces the likelihood of failure, and logically you would think that it would as you are not cycling the lock pins on the lifters that generally are responsible for the failure, but it doesn't guarantee that you won't have a lifter-related issue. Even if the components are stationary, they are still there and they are less robust that a traditional non-DFM/AFM lifter.

 

Disabling the system in my opinion, however, improves the drivability of the vehicle significantly, regardless of reliability implications. I exclusively drive our '21 5.3 8-speed truck in L7 for this reason (but also because we had lifter failure at 585 miles and I'm still sour about it). If you toggle from L7 to D to re-enable DFM at a steady cruise, it feels like getting hit by a headwind and at certain speeds (especially 31 MPH specifically on ours, right before the transmission up shifts) the exhaust almost sounds like a helicopter with it enabled. This is all to say even if it was the most reliable system in the world (which it isn't), it's extremely unpleasant to live with.

 

It's honestly a shame because the valvetrain in the modern 5.3 V8s took what used to be a 250,000+ mile motor in older LS variants and turned it into a 60,000-80,000 mile motor at best. I saw a post here the other day of someone with a 2019 5.3 truck with 78,000 miles that had a lifter go and it took out the whole engine to the tune of $12,000. It's not sustainable to own trucks with these engines out of warranty. I will be genuinely shocked if any significant number of the V8-equipped T1 trucks make it to 100,000 miles with all of the original factory-installed engine components in-tact. Ours didn't even make it to the first oil change.

[JimCost2014]

9 hours ago, Nestor Romero said:

On the window sticker?

Top right-hand corner of the window sticker should tell you, if not scan the QR code in the driver's door jamb. It will bring up the majority of the RPO's that your truck has.

[redwngr]

If wanting  a more complete list than the QR code provides, any dealer can print you a build sheet from the VIN. 

[Amcguy1970]

On 3/10/2022 at 7:19 AM, voided3 said:

The lifters themselves are the failure prone component due to design, but in recent history they also had a bad batch with a manufacturing defect (our truck included). It's believed that disabling DFM/AFM reduces the likelihood of failure, and logically you would think that it would as you are not cycling the lock pins on the lifters that generally are responsible for the failure, but it doesn't guarantee that you won't have a lifter-related issue. Even if the components are stationary, they are still there and they are less robust that a traditional non-DFM/AFM lifter.

 

Disabling the system in my opinion, however, improves the drivability of the vehicle significantly, regardless of reliability implications. I exclusively drive our '21 5.3 8-speed truck in L7 for this reason (but also because we had lifter failure at 585 miles and I'm still sour about it). If you toggle from L7 to D to re-enable DFM at a steady cruise, it feels like getting hit by a headwind and at certain speeds (especially 31 MPH specifically on ours, right before the transmission up shifts) the exhaust almost sounds like a helicopter with it enabled. This is all to say even if it was the most reliable system in the world (which it isn't), it's extremely unpleasant to live with.

 

It's honestly a shame because the valvetrain in the modern 5.3 V8s took what used to be a 250,000+ mile motor in older LS variants and turned it into a 60,000-80,000 mile motor at best. I saw a post here the other day of someone with a 2019 5.3 truck with 78,000 miles that had a lifter go and it took out the whole engine to the tune of $12,000. It's not sustainable to own trucks with these engines out of warranty. I will be genuinely shocked if any significant number of the V8-equipped T1 trucks make it to 100,000 miles with all of the original factory-installed engine components in-tact. Ours didn't even make it to the first oil change.

 

You do realize failures are the exception not the rule right? The failure rate of AFM and DFM (outside of the bad batch) is in the low single digit percent. Saying these don't last past 80k is how misinformation gets started. So no, the LT derived engines aren't a 60-80k mile motor at best, that is just a flat out lie and data easily disproves that. 

 

Outside of our 6.2 that did have the failure and was in the bad batch range at 8k miles, all other LT based AFM/DFM vehicles I personally know or drive have had no issues. Hell my 2014 just turned 100k last week. My buddies 2012 Tahoe with AFM went nearly 300k before trade in (and if you listed to some people on the forums those LS based AFM systems were junk, again false) and I know countless K2's that are well over 100k untouched and no failures. 

 

Disabling AFM and improving significantly how it drives is a placebo effect. The system is pretty much imperceptible if working properly and a clunky downshift isn't tied to the system but rather the transmission. Driving on or off I can't tell any difference. People perceive what they want to if they look hard enough and go in with a predetermined set of results.

 

Tyler

[Black Smoke]

No, the 6.6L L8T engine does not have DFM (Dynamic Fuel Management); it is specifically designed without any cylinder deactivation features like AFM (Active Fuel Management) or DFM, making it a preferred choice for engine builders due to its consistent power delivery across all cylinders

[redwngr]

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