AFM/DFM on 2022 Tahoe?

[jimgeb]

Does anyone know if my 2022 Tahoe has AFM/DFM or was it temporarily deleted from this year due to constraints? The owner's manual has two locations for AFM fuses for the underhood fuse block but the diagram on the actual fuse cover shows no such fuses. The window sticker nor any other documentation show any indication of AFM/DFM delete.

 

[jimgeb]

By the way I forgot to mention above that I have the 5.3L engine (L84).

 

[Eusibius2]

I was thinking a similar question. I just took a long road trip (1500 miles) and never knew if DFM kicked in or not. There were several stretches of road that were straight and flat where cruise was on for a while. I never noticed any noticeable changes in engine noise, no lights on the dash, or anything.

Thoughts?

I'm in a 2022 Z71 with a 6.2L.

 

[jimgeb]

Wish they kept the dash indication that told you when you were in AFM like in my 2015 Tahoe. The deletion of the AFM fuse is puzzling or maybe DFM is programmed into the Engine Control Module and doesn't have a separate fuse. Maybe I'll have to assume that I have DFM since it says so in the 2022 brochure. Only auto start/stop and steering wheel lock was deleted on my 2022 Premier.

 

[Brand0n]

What does your sticker say for engine type? I believe it will list “without DFM” if it doesn’t have it.

 

[jimgeb]

What does your sticker say for engine type? I believe it will list “without DFM” if it doesn’t have it.

It's the 5.3L engine, but no mention of DFM. While I was familiarizing myself with the fuse blocks, I was puzzled by the absence of the AFM fuses that were mentioned in the owner's manual and no mention of a DFM fuse, so I thought that maybe the DFM was deleted due to constraints. The only deletions listed on the window sticker were auto start/stop, which I'm glad I don't have, and the steering wheel lock, so I assume I have DFM.

 

[Brand0n]

That is strange…not too sure why it would be missing. On the silverados the engine type in the upper right corner of the sticker shows “5.3L ECOTEC3 V8 *W/O DFM*” if you don’t have it. I believe I read that’s the case for the SUVs as well. If you email your dealer they can pull the full build sheet which would confirm.

 

[jimgeb]

That is strange…not too sure why it would be missing. On the silverados the engine type in the upper right corner of the sticker shows “5.3L ECOTEC3 V8 *W/O DFM*” if you don’t have it. I believe I read that’s the case for the SUVs as well. If you email your dealer they can pull the full build sheet which would confirm.

I checked the window sticker and it only says "ENGINE: 5.3L ECOTEC3 V8" and does not say "DFM" or "w/o DFM". I'm still puzzled by the absence of the AFM fuse on the fuse block diagram and no mention of a DFM fuse. I'll discuss with my dealer as you suggested. Thanks.

 

[jimgeb]

It would be interesting to find out if the lifters fail as much even if AFM/DFM is deleted.

 

[WalleyeMikeIII]

I don’t think it was ever “deleted” from the Tahoes/Yukons/Eskys

 

[jimgeb]

I don’t think it was ever “deleted” from the Tahoes/Yukons/Eskys

To clarify, I meant it would be interesting to know if lifters still fail as much if AFM is bypassed by a aftermarket device.

 

[Garth Knight]

Anyone able to chime in about AFM/DFM and lifter failure? I'm hoping it can be disabled if it will prevent lifter failure. Oh and for the record my window sticker says 6.2L ECOTECH V8. No mention about the AFM/DFM.

 

[WalleyeMikeIII]

Anyone able to chime in about AFM/DFM and lifter failure? I'm hoping it can be disabled if it will prevent lifter failure. Oh and for the record my window sticker says 6.2L ECOTECH V8. No mention about the AFM/DFM.

You are opening a Pandora’s box with this question.

Facts as I know them:
1) In late 2021, GM admitted there was a date range of engines built with potentially faulty lifters in early 2021
2) GM never recalled these engines, but did have some actions related to them, including asking dealers to replace both banks of lifters on any vehicle not yet sold which fell in the date range, replacing both banks on a customer vehicle in the date range if a failure occurred in less than 8k miles (May have been increased to 16k at some point?), and increasing power train warranty to 100k miles on customer vehicles that failed.
3) Some small number of people have had lifter failures more than once.
4) Most people have not had any lifter failures
5) Some vehicles outside the specified date range from GM have had lifter failures (believed to be small number)
6) GM has been using a version of these lifters since AFM appeared in 2009, and has had some of these lifters fail dating back that far. But now instead of them being on 4 of the 8 cylinders (AFM), they are on all 8 cylinders (DFM)
7) There is no known way to “disable permanently” the DFM in the current generation 5.3 and 6.2 L engines, given how locked down the ECU now is. And it is unclear, without a mechanical delete (replacing the collapsible lifters with non collapsible lifters) that there would be an increase in reliability.

Now, what all that means to long term reliability, none of us know. We all have 5 year, 60k mile power train warranty to find out.

Note, I owned a 2013 Suburban with AFM which gave me 115k trouble free miles. It was maintained by the maintenance schedule in the owners manual.

 

[SSGUNNER]

Anyone able to chime in about AFM/DFM and lifter failure? I'm hoping it can be disabled if it will prevent lifter failure. Oh and for the record my window sticker says 6.2L ECOTECH V8. No mention about the AFM/DFM.

My sticker also has no mention of DFM but i still got it.

Unless your sticker says DFM delete you got it…

 

[ZKWBQD]

You are opening a Pandora’s box with this question.

Facts as I know them:
1) In late 2021, GM admitted there was a date range of engines built with potentially faulty lifters in early 2021
2) GM never recalled these engines, but did have some actions related to them, including asking dealers to replace both banks of lifters on any vehicle not yet sold which fell in the date range, replacing both banks on a customer vehicle in the date range if a failure occurred in less than 8k miles (May have been increased to 16k at some point?), and increasing power train warranty to 100k miles on customer vehicles that failed.
3) Some small number of people have had lifter failures more than once.
4) Most people have not had any lifter failures
5) Some vehicles outside the specified date range from GM have had lifter failures (believed to be small number)
6) GM has been using a version of these lifters since AFM appeared in 2009, and has had some of these lifters fail dating back that far. But now instead of them being on 4 of the 8 cylinders (AFM), they are on all 8 cylinders (DFM)
7) There is no known way to “disable permanently” the DFM in the current generation 5.3 and 6.2 L engines, given how locked down the ECU now is. And it is unclear, without a mechanical delete (replacing the collapsible lifters with non collapsible lifters) that there would be an increase in reliability.

Now, what all that means to long term reliability, none of us know. We all have 5 year, 60k mile power train warranty to find out.

Note, I owned a 2013 Suburban with AFM which gave me 115k trouble free miles. It was maintained by the maintenance schedule in the owners manual.

>> We all have 5 year, 60k mile power train warranty to find out. <<
My new 2022 Tahoe that I waited nearly a year to get only came with a 3 year, 36K mile power train warranty.

 

[B-train]

For real? If that's correct, that is total BS. I would also go so far as to say it's a cover up to lower warranty costs they know will be there possibly for all the above mentioned concerns. It's not enough to charge 80K for a new truck, but you get 2 years of average use out of it and then on to customer pay rates? FOR EVERYTHING?

 

[Chad G 1979]

>> We all have 5 year, 60k mile power train warranty to find out. <<
My new 2022 Tahoe that I waited nearly a year to get only came with a 3 year, 36K mile power train warranty.

Are you sure? My 23 i picked up 2 weeks ago has 3/36k bumper to bumper warranty and 5/60k drivetrain warranty. I would double check with your dealer.

 

[WalleyeMikeIII]

>> We all have 5 year, 60k mile power train warranty to find out. <<
My new 2022 Tahoe that I waited nearly a year to get only came with a 3 year, 36K mile power train warranty.

Pretty sure all GM Passenger Vehicles have a 3/36 Bumper to Bumper, a 5/60 Powertrain, a 6/72 on Airbags and Seatbelts, 6/100k for rust through, and and 8/80 or 7/70 On Emissions (depending on where you are).
See Chevrolet.com and search under warranty under the support section (linked for your covenience)....or check the warranty pamphlet in your owners manual package in the glove box.
Excerpt below:

 

[0x_2a]

Good News - It is Now Possible
Bad News - You probably don't want to
- Lifters are failing from parts outside DFM
- It voids the warranty
- Requires 20+ hours from a "very" experienced mechanic who can spot other defects that might be in the motor

Lifters Failures Without DFM, from a GM Master Tech friend
- 2023 Oversized Lifter Bore Defect, i.e. the lifter tube is to big, lifter rocks, causes a bent rod
- 2022 Main Bearing Cap Bolt Defect, i.e. bad torque on the bolts, misaligns the crankshaft
- 19-23 Oil Pump Defect, i.e. bad oil pressure, bad lifter activation
- 21 Plunger Spring Rod Wear , i.e. lifter spring rubs rod, causes a bent rod
- Lifters are sensitive to which oil/gas/cleaners you buy
-- Gas low on detergents lets carbon build up, jamming the lock-spring in the lifters
-- Oils low on detergents let carbon build, jamming the lock-spring in the lifters

How to Disable DFM if You Really Want it Disabled

For DIY electronic and mechanical, the cost appears to be ~$2,000 and 20+ labor hours for an experienced mechanic, also having to pull out and send in your ECM.

Electronic Disable
HPTuners released send-in program for Global B ECMs! You have to pull out your ECM, send it in, and they "upgrade" it with a chipboard harness. Thing's you'll need:
- Being OK with voiding your warranty
- Couple weeks turnaround without your truck (pull and send in your ECM)
- $800 for 22-24 L87 ECM mod: https://www.hptuners.com/product/gm-e90-ecm-service-global-b/
- $400 for the OBD2 connector: https://www.hptuners.com/mpvi3/#custom_form_mpvi2
- $300 ($400 on Yukons) for 6 License Credits https://www.hptuners.com/vehicles/#supported-vehicles
- A Windows laptop to run their VCM Suite (free download)

Mechanical Disable
Michigan Motorsports stocks delete kits. Don't know if this 2019+ kit actually goes to 2024. Should call and ask.
- $400 Mechanical Lifter Delete Kit https://www.michiganmotorsports.com...dfm-lifter-delete-kit-dod-afm-6-2l-gen-v-kit/