[ Active Fuel Management DELETE ]

Visit my Facebook page for a lot of New Pictures & Harness Guides YouTube channel for How To videos  - E-Mail: brendan@lt1swap.com

I have gotten a lot of questions if I was still doing programming, answer is YES, I have not stopped doing programming, nor do I plan to at all. This is my full time job. LT1SWAP.COM was created in 2002. 20 years later I'm still here!   Thanks, Brendan - 7/17/2023  -  The work coming in the door takes top priority, followed by email/phone. AFM Programming also gets top priority so be sure to mark package "AFM" on the outside. 

If you have found this page you may be experiencing issues with your 2007-2018 GM Truck or SUV/Car that has the active fuel management, or sometimes called DOD (Displacement on Demand)  This is the system that shuts down half the lifters in the engine and places it in a 4 cylinder operation mode.  While this idea to shut down cylinders to reduce fuel consumption sounded great on paper, it has also been causing a lot of issues for people.  Some of the issues observed deal with oil consumption, fouled spark plugs, and in some cases failed lifters, and repeat failures of lifters.  Repair process gets expensive due to requirement of removing the cylinder heads to replace lifters.  There are options to mechanically delete AFM from your engine when failure happens. (programming ECM required) To learn about that continue to read below. As a preventive measure you can have AFM disabled in your ECM programming, which is a service I offer. For probably the best video information, and some tools/parts for AFM repair, visit, Crazed Performance Repair CPR has tools to help release stuck lifters, as well as tips and tricks to help prevent reoccurrence of lifter problems. Also has a list of shops around the USA that have done these repairs and deletes, and willing to do them for you.

ALL VEHICLE WITH ACTIVE FUEL MANAGEMENT NOW $50.00 for AFM delete programming, with USPS Priority Mail return shipping included in the price! $25 additional for Express 1-2 Day shipping, $50 additional if your PCM requires VIN programming before AFM Delete. (new pcm or from different vehicle) If you have a Hybrid vehicle with AFM system, as far as I am aware, you can not delete the AFM system, at least I CAN NOT do the programming.  Hybrid=battery/electric motor drive.     Flex Fuel vehicles is no problem.    PLEASE read on below to learn more about the mechanical side of the AFM system, if all you need is the programming service, use the buy now button below. 2019+ Pickups with the E90 ECM, L84/L87 engine I am unable to do ANY programming for. 2019, 2020 Tahoe, Yukon, Suburban with L83 or L86 I can still do no problem. These still used the E92 computer.

Select Service Below, USA Addresses ONLY

Ship your ECM to:

Brendan Patten

5411 County Road 2350

Pomona MO 65789

ph. 417 277 5836 <-- Land Line

*7/17/2023 my phone has been down for a few days due to a fiber optic line cut, small town telephone company so kind of slow getting it fixed!

2014-2018 Vehicles with direct injected engine, L83 5.3L, L86 6.2L: Complete AFM delete is now possible, but will use some different parts, see here for details. 

The programming for preventive measure on your stock engine that currently runs fine, and the programming for a mechanically deleted engine ARE THE SAME. Devices such as the Range Technology AFM Disabler, DiabloSport AFM Disabler and hand held programmers, such as Superchips, Hypertech, may allow you to disable AFM on a completely stock engine, but these devices WILL NOT disable diagnostic codes for AFM. If you do a mechanical AFM delete, these devices WILL NOT WORK. ECM Must be programmed with laptop based tuning software, such as service I offer below.

These are for USA Address only. If you are in Canada, or International, contact me prior to purchasing.




I have been working with a few local shops; we have had dozens of trucks in my small town already with repeated lifter failures after replacement with new AFM lifters. The AFM lifters appear to fail two different ways.   I have seen the lifter come a apart, causing valves to bend, and have also seen them get stuck in a compressed position, causing valves to stay closed, and pushrod to bounce around unloaded.  I believe that the lifter should not fail as soon, or maybe not at all, if you disable the cycling from on to off of the AFM lifter.  There are some vehicles where I have seen worn lifter guides, causing the AFM lifter to rotate slightly, and go into deactivated position on its own, also there are issues with the oil control solenoids that leak oil when not commanded, also causing cylinder deactivation.

sample of lifters, some old design, some newer, some locked down

new & old lifter design, both locked down. new design has larger oil feed for inner lifter body, and slot/pin to keep internal part from rotating

was locked down, old design, inner part allowed to rotate, wear on ledge pins sit on.

this lifter from same engine as picture left, same old design, but no wear at all.

new style lifter with pin to prevent rotation. now wear is concentrated in one area, this lifter was also locked down.

metal debris on pin, likey wedged in lifter causing to stay locked down


OIL CONSUMPTION:  It is my conclusion that the oil consumption has something to do with a spray or mist of oil created when the lifters exit the cylinder shut down mode and the oil used to compress the lifter is exhausted. This oil sprays on bottom of cylinders and enters the PCV system, drawn into the intake and burned. This means depending on each persons driving style, the more the engine enters/exits 4 cylinder mode, the more oil consumption you may see.  This theory is backed up by the presence of oil fouling on spark plugs, which is usually worse on the AFM cylinders, but is present on all 8 cylinders. Some vehicles with 3+ qt consumption in an oil change the AFM delete dropped it by half, and an updated valve cover replacement further dropped the oil consumption. 2007-2010 vehicles there is an updated valve cover with revisions to the baffle/shield under the drivers side valve cover.  read this: https://static.nhtsa.gov/odi/tsbs/2012/SB-10062524-7690.pdf  GM also has a shield that goes over a valve in the oil pan. This IS NOT needed if AFM is disabled.  I have done the AFM delete and the new valve cover on vehicles and completely eliminated oil consumption.

I have programmed hundreds of local trucks to simple disable the AFM. Last year I have programmed over 350 mail order ECM's for people doing hardware deletes using methods I describe here! Most notice almost no difference in fuel economy due to the very tight conditions required to enter 4 cylinder mode. (2014+ direct injected engines may see 1.0 to 1.5 MPG loss when disabling AFM)  Oil consumption appears to be eliminated by disabling the AFM system when valve cover was replaced, as would be expected if my above theory is correct.  Some vehicles may be too far gone; oil rings already to dirty to come back to life. I have seen a few vehicles that oil use tapered off over a year following AFM delete. 

DISABLING THE AFM SYSTEM: If your vehicle is currently running with no mechanical problems; meaning, no misfires due to no compression, no stuck lifters, no loud lifters, I believe simply programming the ECM to disable the AFM activation will prolong the life of the engine, and eliminate oil consumption.  If you have experienced a lifter failure, and have a cylinder with zero compression, lifter replacement is now required! I would highly suggest removing the AFM hardware from the engine since you will have the cylinders heads off anyways.  !!!PROGRAMMING REQUIRED IF YOU REMOVE THE AFM HARDWARE!!! If you remove the AFM components, and start the engine, DTC P3401, P3425, P3441, P3449 will set. These are codes for the 4 solenoids that control AFM. When these codes set, the PCM will disable the injectors for those cylinders.  So the ECM has to be programmed to disable those diagnostic codes.  See bottom of this page for programming info. Devices such as the Range Technology AFM Disabler, DiabloSport AFM Disabler and hand held programmers, such as Superchips, Hypertech, may allow you to disable AFM on a completely stock engine, but these devices WILL NOT disable diagnostic codes for AFM. If you do a mechanical AFM delete, these devices WILL NOT WORK. ECM Must be programmed with laptop based tuning software, such as service I offer below.

If you have had a lifter stick and the pushrod/rocker arm is loose, there is a chance you maybe able to free it up. Watch this video below.  Programming should still be done to disable AFM to prevent reoccurrence of the failure. This method could save you some time and money getting you back on the road.  More info and the tools used for this are found here:  Crazed Performance Repair

PARTS NEEDED FOR COMPLETE AFM MECHANICAL DELETE : I recommend Summit Racing for GM Parts. Always in stock I have found, and fast shipping!  Any GM dealership should do as well. Amazon/Ebay I don't always trust where the parts are coming from, that's a choice for you.

Head Gaskets GM PART# 12498544 for a PAIR, 2 head gaskets. These are the exact same gaskets you probably removed. Will say 5.3 HO / 5.7 on the gasket its self.  6.0 6.2 should use proper head gaskets for that engine.

Head bolts GM PART# 17800568 Stock GM head bolts, enough for 1 cylinder head, so buy 2 of this part if doing both heads to do the full delete.

Valley Cover Plate - GM Part# 12598832 This will replace the stock valley cover that contains the oil control solenoids responsible for activating AFM. This new valley cover will also block off the 8 oil ports on the block. Should include gaskets. No need to drill & tap the towers, or otherwise seal the towers, this cover does that for you. !!!!THIS COVER IS ONLY TO BE USED IF INSTALLING STANDARD NON-AFM CAM/LIFTERS.  DO NOT USE IF YOU STILL HAVE THE STOCK AFM CAM/LIFTERS INSTALLED!!!!!


Lifters - GM Part# 12499225  Your AFM engine will have 8 standard lifters, and 8 AFM lifters.  This part# gets you 16 new standard lifters.

Timing Cover Gasket Set - Fel Pro Part# TCS45993 includes gaskets for timing cover, harmonic balancer seal, water pump, and oil pump pick-up tube o-ring.

Lifter Guides - GM Part # 12595365 These are the plastic guides that keep the lifters from rotating, keeping the roller going correct direction on the cam lobe. These guides are different for AFM lifters, and you will need 4 of these.

Cam Thrust Plate - GM PART# 12589016  This part retains the camshaft in the block and also has an oil seal that is likely flattened out and should be replaced.

CAMSHAFT - The AFM engines have a special camshaft.  The mechanism required for the AFM lifters to turn on/off requires the individual lobes of the cam with AFM lifters riding on them to be DIFFERENT than adjacent lobes with standard lifters.  You MUST replace the camshaft if you are going to replace the AFM lifters with standard lifters.  Failure to do so will result in 4 cylinders that are about 25 lbs low on compression. This WILL cause misfires at idle.  (Learned this the hard way, take my word, CHANGE THE CAMSHAFT)

2014+ Gen 5 Engine Family, including 5.3L L83, 6.2L L86 with direct injection, you now have a camshaft that will allow STOCK drivability, with AFM deleted. Brian Tooley Racing offers part# 2249399130.  AFM delete on these engines is similar. They will use the same lifters and lifter guides as Gen IV engines. You will need aluminum plugs to block the oil passage under the stock valley cover, reusing the stock valley cover.  That's it!  You can get oil plugs from BTR here.  These tap into the oil holes, or you can get a rivet style plug from summit racing here.

GM PART# 12689035 is the stock camshaft used in the 4.8L/5.3L engine that DID NOT come with AFM.  This camshaft is a direct replacement for the 5.3L AFM cam when you want to do the AFM delete and use standard lifters.  This cam will have a groove in the 2nd bearing journal that is used to supply oil for use in VVT (variable valve timing) that started in 2010.  This cam works just fine in 07-09 WITHOUT VVT, as well as 10+ WITH VVT when deleting AFM from 5.3l engines.  This cam will use the stock single bolt timing gear and bolt from the 07+ engines as well.  As of this writing, this cam is around $118 brand new from GM, you can also get it on Amazon, Summit Racing, so on.  Most all GM parts are on Amazon or Summit Racing. (This cam WILL NOT work for 2005-2006 5.3L Envoy, Denali, Impala SS, Monte Carlo SS or any engine with the E40 ECM those two model years. You must have 3 bolt cam sprocket for those applications.)

GM PART# 12623065. This cam is the factory 6.2L L9H camshaft from non-afm 6.2 in 2009+. Use this for 2007+ applications on 6.0/6.2 when deleting AFM for best matching lobes for the larger engine/heads used on these engines. This cam also uses the stock single bolt timing gear and bolt, works with or without VVT.

2nd option for camshaft; the cheapest way is to find a used 4.8/5.3/6.0 camshaft from 1999 to 2007 Gen 3 engine that did not have AFM. These can often be had for as cheap as $20 online.  There is one small difference. The Gen 3 camshafts use 3 bolts to hold the timing gear on, and the 2007+ use a single large bolt in the center.  On the 2007+ engine you must use a cam gear that has a 4x trigger wheel for the camshaft position sensor.  GM Part# 12586481 has a 3 bolt flange, and 4x trigger and will do this task and costs about $25.00.  The gen 3 camshaft option WILL NOT WORK if you have a 2010+ with VVT.  In that case, use the previously listed GM PART# 12689035 camshaft.

3rd option for camshaft, is to purchase an upgraded performance camshaft.  If you go this route, such as a COMP cam, you can ask for a Gen 3 cam grind, made on a single bolt core.  You need to let them know your intention to remove the AFM lifters, and you need all the intake lobes the same, and all exhaust lobes the same.  Some cam manufactures are making camshafts to be used with the AFM lifters, so be sure to get this right...  On the 2007+ trucks even the smallest performance camshafts will need a custom tune to get it to run perfect. You need to find a local tuner or dyno shop to talk about options after the cam install.

Camshaft sprocket bolt part# 11561283 for single bolt camshaft. This is a one time use bolt according to GM, its about $4.00

2007+ All Vehicles MUST use a 4x cam gear pattern.  You can get this gear for a 3 bolt camshaft, or single bolt camshaft. 2010+ will have VVT Cam Phaser.

4x Single Bolt Cam Gear

Factory gear used on 07+ Full Size Pickups & SUVs without VVT GM Part# 12591689

4x Three Bolt Cam Gear

This cam gear is used on a few different applications, and can be used if you use a 3 bolt non afm camshaft during your AFM delete. GM Part# 12586481

4x Cam Phaser Assembly

This is the Cam Phaser used on VVT engines 07+ Starting in 2010 all 4.8 and 5.3 use this. You can Delete VVT by changing back to 07-09 timing cover and sprocket/bolt.

Two timing covers used.

On left is the vvt timing cover, on right is non-vvt.

Both have cam sensors. Deleting VVT requires using non-vvt timing cover.

VVT, Variable Valve Timing - Some vehicles starting in 2007 had VVT, the 6.0L LY6, L76, and 6.2L engine family in the trucks ALL had VVT. Starting in 2010 ALL 4.8/5.3 engines also had VVT.  This required a change to the camshaft, which will be a groove in the 2nd bearing journal to supply oil to the VVT control valve located inside the cam bolt on these engines.  If you are doing the AFM delete on an engine with VVT, you can decide to keep the VVT, or get rid of it too.  Removing VVT will require a new timing cover, cam gear, and cam gear bolt.  The camshaft part# 12689035 for 5.3L listed above will work with or without VVT.  IF YOU WILL BE DELETING VVT, AND I WILL BE PROGRAMMING YOUR ECM, YOU MUST LET ME KNOW BOTH AFM/VVT WILL BE DELETED, BY DEFAULT, I WILL ONLY DELETE AFM ON ECM'S I RECIEVE.


ECM should be original to the vehicle.  If you wish to purchase a spare ECM, and ship it instead, you will have to have security relearned.  The ECM you purchase MUST have the exact same Service Number on the white sticker. There is an additional $25 for VIN programming, select service below in the white box.  GM Sometimes has new software for your vehicle, including some recalls for emissions.  If you take your vehicle in for a recall that involves reprogramming the ECM, they will overwrite the AFM Delete programming I do.  This could result in only running on 4 cylinders if you have done a mechanical delete.  I can perform the same GM programming and get you the latest GM software for your vin.  To see what updates maybe available for your vehicle, click here, enter your VIN, click 'Get CAL ID', Select 'ECM Engine Control Module', click 'Next', and click 'Complete History'  This will show all software for your ECM specific to your VIN#.  There are 8 modules in your ECM.  Some scan tools will display what your current vehicle software is, and you can use this tool to see if updates are available, and what that update is for. If you want this service at time of AFM delete, select it below by clicking in the white box, and choose the option with VIN Program, and select which shipping option you want. Please note, an ecm which is programmed with NEW GM software, may require a relearn procedure once you get it back in and running. If you get  P0315 code, this will mean you need to have a "crankshaft position sensor variation lean" procedure done with a scan tool.  This code will not cause any poor running or issue, but will prevent ECM from detecting misfires until the relearn is completed.

IF YOU HAVE A 2005 or 2006 TRAILBLAZER, ENVOY, RAINIER, OR SAAB 9-7X with the LH6 5.3L, Impala SS, Monte Carlo SS with LS4 5.3L, you have an E40 ECM, and your engine uses a different cam and crank trigger as 2007+ and later engines. You will have a 3 bolt camshaft, so using the NEW camshaft part# I list above is not going to work for you.  You should find a used 99-07 LM7/LM4 or L33 camshaft. 2007+ Trailblazer, Envoy, Saab programming on E67 ECM is same as 07+ pickup. More info here>> VERY IMPORTANT INFORMATION IF YOU HAVE A 2005-2006 TRAIL BLAZER, ENVOY, RAINIER, SAAB 9-7X, IMPALA, MONTE CARLO << click here

I also do $50 AFM delete on 2007-2008 3.9L LZ8 V6 Impala applications. These use the E38 ECM same that is used in the pickup trucks 07-13.  The 3.9L could come with or without AFM, so sometimes if a shop installs the wrong engine, AFM must be disabled for engine to run correctly. I have also programmed so shops could put a different 3.9L or even the smaller 3.5L in place of the 3.9L and disable AFM. This seems to work well too.

ECM LOCATION UNDER HOOD I only need the ECM, unplug it, and remove from bracket.

If you have these buttons, cycle top button until display shows 'instant economy''

You can monitor the vehicle cycling into/out of V4/V8 mode.

e38 ECM, used 07-14 trucks. $50 programming option

2007: 12597121

2008: 12612384

2009: 12625455

2010-11: 12633238

2012+ ????

E40 ECM used in 2005 and 2006 Envoy, Trailblazer, Saab 97x, Impala SS, Monte Carlo SS

E67 ECM used 2007+ envoy, trailblazer, saab 97x use $50 programming option.

2014-2016 5.3L L83, 6.2L L86 ECM used on direct injected engines


How to properly clean and remove E38/E67 ECM Harness Connectors 

also a YouTube video here showing removal of ecm: https://youtu.be/zQJlmCuTtMY

Ship to:  

Brendan Patten

5411 County Road 2350

Pomona, MO 65789

If you mark the outside of the box with black marker in big letters AFM, and ship it to me USPS, I often will program, and ship back out the SAME DAY! Be sure payment is included inside the box, or made prior to me receiving the ECM for the quickest turn around time. Any questions on this call me, 417-277-5836 <<< land line no text!  

E-Mail with questions: brendan@lt1swap.com


Select Service Below, USA Addresses ONLY