{"product_id":"afm-dfm-vcm-disabler-gmc-yukon-2007-2018-afm-dfm-disabler","title":"GMC Yukon 2007-2018 5.3L\/6.0L\/6.2L V8 AFM\/DFM Disabler","description":"\u003cp\u003eA plug-in cylinder-deactivation disabler for the 2007–2018 GMC Yukon. It goes into the OBD-II diagnostic port and keeps the factory Active Fuel Management system from engaging, so the engine runs on every cylinder all the time. There is no tune involved and nothing inside the engine is changed. Pull it out of the port and the factory strategy returns.\u003c\/p\u003e\u003ch2\u003eVehicles, years and engines\u003c\/h2\u003e\u003cp\u003eEach row below is listed as a 100% fitment match:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e2007–2009 GMC Yukon: 5.3L V8 \/ 6.0L V8\u003c\/li\u003e\n\u003cli\u003e2010–2014 GMC Yukon: 5.3L V8 \/ 6.0L V8 \/ 6.2L V8\u003c\/li\u003e\n\u003cli\u003e2015–2017 GMC Yukon: 5.3L V8 \/ 6.2L V8\u003c\/li\u003e\n\u003cli\u003e2018 GMC Yukon: 5.3L V8\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eAFM-equipped engine codes that GM used in these years and sizes:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003eLY5 (5.3L, 2007–2009, VIN 8th digit \"J\")\u003c\/li\u003e\n\u003cli\u003eLC9 (5.3L, 2007–2011, VIN 8th digit \"3\")\u003c\/li\u003e\n\u003cli\u003eLMG (5.3L, 2007–2014, VIN 8th digit \"0\")\u003c\/li\u003e\n\u003cli\u003eL76 (6.0L, 2007–2009, VIN 8th digit \"Y\")\u003c\/li\u003e\n\u003cli\u003eLFA (6.0L, 2008–2009, VIN 8th digit \"5\")\u003c\/li\u003e\n\u003cli\u003eLZ1 (6.0L, 2010–2013, VIN 8th digit \"J\")\u003c\/li\u003e\n\u003cli\u003eL83 (5.3L, 2014–2018, VIN 8th digit \"C\")\u003c\/li\u003e\n\u003cli\u003eL86 (6.2L, 2014–2018, VIN 8th digit \"J\")\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003eIn the same trucks and SUVs, GM also built V8s without AFM, for example the 5.3L LH9 (2010–2012 trucks, VIN code P), the 6.0L LY6 and L96 and the 6.2L L9H. Those engines never deactivate cylinders, so the module has nothing to manage on them. Check your code against both lists before you buy.\u003c\/p\u003e\u003cp\u003eIf your engine code is not in this list, email the VIN to support before ordering so we can confirm the application.\u003c\/p\u003e\u003ch2\u003eHow Active Fuel Management operates\u003c\/h2\u003e\u003cp\u003eOn AFM V8 engines, the computer shuts off fuel and holds the valves closed on cylinders 1, 7, 6 and 4 when the load is light, so the engine runs as a V4. It does this through special collapsible lifters on those cylinders, fed by oil-pressure solenoids. When you ask for more power, the lifters lock again and all eight cylinders fire. GM describes this behavior in its service bulletin on AFM and DFM operation.\u003c\/p\u003e\u003cp\u003eGM replaced AFM with Dynamic Fuel Management (DFM) on the 5.3L L84 and 6.2L L87 starting with the 2019 Silverado 1500 and Sierra 1500. The engines covered here use the earlier AFM design.\u003c\/p\u003e\u003ch2\u003eWhat owners are after\u003c\/h2\u003e\u003cp\u003eOwners usually disable AFM for one of three reasons: they notice the change between modes as a vibration or exhaust drone, they want a consistent throttle response while towing or climbing grades, or they want to limit how often the deactivation lifters switch. Keeping the engine on all cylinders addresses all three. The tradeoff is that you give up whatever fuel saving AFM was providing in light cruising.\u003c\/p\u003e\u003ch2\u003eDiagnose existing problems first\u003c\/h2\u003e\u003cp\u003eKeep the oil at the correct level and grade before and after installation. AFM lifters and their solenoids are oil-pressure operated, so an engine that is low on oil or running the wrong grade should be sorted out first. The module stops the switching, but it is not a substitute for maintenance or for repairing an engine that already has a fault.\u003c\/p\u003e\u003ch2\u003eKeep up with oil changes\u003c\/h2\u003e\u003cp\u003eDisabling cylinder deactivation does not replace normal maintenance. Use the oil grade and change interval GM lists for your engine, watch the oil level between changes, and repair leaks promptly. The valvetrain on these engines depends on clean oil at proper pressure in every mode.\u003c\/p\u003e\u003ch2\u003eLiving with it\u003c\/h2\u003e\u003cp\u003eBecause it occupies the OBD-II port, unplug the module before connecting a scan tool, an insurance logger or an emissions-test probe, then plug it back in afterwards. Make sure it sits clear of your left knee and the pedals, and that the housing is fully seated in the port.\u003c\/p\u003e\u003ch2\u003eModule, tune or delete kit\u003c\/h2\u003e\u003cp\u003eOwners who want AFM gone for good sometimes go the mechanical route: non-AFM lifters, a matching camshaft and a retune. That is a large job and it is permanent. A tuner can also disable AFM in the engine computer. The plug-in module sits at the other end of the scale: no parts replaced, no software rewritten, and back to factory with one pull. It is meant for engines that run well and simply should not switch modes.\u003c\/p\u003e\u003ch2\u003eWhat changes when you drive\u003c\/h2\u003e\u003cp\u003eThe difference shows up in light-load driving: steady highway speeds, gentle acceleration and coasting down small grades. Those are the moments when AFM used to drop cylinders. With the module in, engine behavior there should feel the same as under heavier throttle. Full-throttle performance does not change, because AFM was never active at full throttle anyway.\u003c\/p\u003e\u003ch2\u003eHow to confirm your engine code\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eYour model year, model and engine match a row in the table (2007–2018 GMC Yukon).\u003c\/li\u003e\n\u003cli\u003eThe quickest checks are the 8th digit of your VIN, which identifies the engine, and the RPO list on the Service Parts Identification label (glovebox or trunk on most pre-2018 GM models, QR code on the driver-door pillar label from 2018).\u003c\/li\u003e\n\u003cli\u003eThe engine runs cleanly with no stored misfire or AFM codes.\u003c\/li\u003e\n\u003cli\u003eIf the vehicle has an engine swap, an aftermarket tune or a replacement engine computer, contact support first.\u003c\/li\u003e\n\u003cli\u003eQuestions: support@automotivebypass.com with your VIN.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eFitment table with engine codes\u003c\/h2\u003e\u003cp\u003eThe full fitment data, by year, alongside matching AFM engine codes:\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eYear\u003c\/th\u003e\n\u003cth\u003eMake\u003c\/th\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eEngine\u003c\/th\u003e\n\u003cth\u003eAFM codes\u003c\/th\u003e\n\u003cth\u003eListing note\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e2007\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8 \/ 6.0L V8\u003c\/td\u003e\n\u003ctd\u003eLY5, LC9, LMG, L76\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2008\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8 \/ 6.0L V8\u003c\/td\u003e\n\u003ctd\u003eLY5, LC9, LMG, L76, LFA\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2009\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8 \/ 6.0L V8\u003c\/td\u003e\n\u003ctd\u003eLY5, LC9, LMG, L76, LFA\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2010\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8 \/ 6.0L V8 \/ 6.2L V8\u003c\/td\u003e\n\u003ctd\u003eLC9, LMG, LZ1\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2011\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8 \/ 6.0L V8 \/ 6.2L V8\u003c\/td\u003e\n\u003ctd\u003eLC9, LMG, LZ1\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2012\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8 \/ 6.0L V8 \/ 6.2L V8\u003c\/td\u003e\n\u003ctd\u003eLMG, LZ1\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2013\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8 \/ 6.0L V8 \/ 6.2L V8\u003c\/td\u003e\n\u003ctd\u003eLMG, LZ1\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2014\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8 \/ 6.0L V8 \/ 6.2L V8\u003c\/td\u003e\n\u003ctd\u003eLMG, L83, L86\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2015\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8 \/ 6.2L V8\u003c\/td\u003e\n\u003ctd\u003eL83, L86\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2016\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8 \/ 6.2L V8\u003c\/td\u003e\n\u003ctd\u003eL83, L86\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2017\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8 \/ 6.2L V8\u003c\/td\u003e\n\u003ctd\u003eL83, L86\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2018\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003ctd\u003eYukon\u003c\/td\u003e\n\u003ctd\u003e5.3L V8\u003c\/td\u003e\n\u003ctd\u003eL83\u003c\/td\u003e\n\u003ctd\u003e100% Fitment Match | OEM-Grade Quality | Plug \u0026amp; Play\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch2\u003eAbout these engine codes\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eLY5\u003c\/strong\u003e: iron-block 5.3L Vortec used in 2007–2009 trucks and SUVs, without variable valve timing or flex-fuel capability. VIN engine digit \"J\".\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLC9\u003c\/strong\u003e: aluminum-block 5.3L flex-fuel (E85-capable) truck and SUV engine, with variable valve timing added from 2010. VIN engine digit \"3\".\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLMG\u003c\/strong\u003e: 5.3L flex-fuel truck and SUV engine, with variable valve timing from 2010. VIN engine digit \"0\".\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eL76\u003c\/strong\u003e: aluminum-block 6.0L V8 with rectangular-port heads; the 2007–2009 truck version also has variable valve timing. VIN engine digit \"Y\".\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLFA\u003c\/strong\u003e: 6.0L V8 used in the Two-Mode Hybrid trucks and SUVs, with variable valve timing. VIN engine digit \"5\".\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLZ1\u003c\/strong\u003e: 6.0L hybrid V8 for 2010–2013 Two-Mode Hybrid models, flex-fuel capable with variable valve timing. VIN engine digit \"J\".\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eL83\u003c\/strong\u003e: 5.3L EcoTec3 V8 with direct injection, variable valve timing and flex-fuel capability. VIN engine digit \"C\".\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eL86\u003c\/strong\u003e: 6.2L EcoTec3 V8 with direct injection and variable valve timing. VIN engine digit \"J\".\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003ePreparation\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003eRead codes first; repair existing misfire or lifter faults before relying on the module.\u003c\/li\u003e\n\u003cli\u003eTop up the oil to the full mark with the correct grade.\u003c\/li\u003e\n\u003cli\u003eIgnition off.\u003c\/li\u003e\n\u003cli\u003eFind the OBD-II port under the dash.\u003c\/li\u003e\n\u003cli\u003eSeat the module fully and keep it away from the pedals.\u003c\/li\u003e\n\u003cli\u003eStart the engine.\u003c\/li\u003e\n\u003cli\u003eTest at light cruise and check that the reduced-cylinder mode no longer appears.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eTroubleshooting\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eWarning light appears:\u003c\/strong\u003e Remove the module, scan for codes and email support with the code and VIN.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eMode changes still felt:\u003c\/strong\u003e Re-seat the module and confirm your engine code is on the AFM list for this listing.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eShop cannot reach the diagnostic port:\u003c\/strong\u003e Unplug the module for the visit and refit it afterwards.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eLifter noise or misfire codes:\u003c\/strong\u003e These point to existing engine faults that need diagnosis and repair.\u003c\/p\u003e\u003ch2\u003eWhich 6.2L engines have AFM\u003c\/h2\u003e\u003cp\u003eGM's 6.2L truck V8 changed three times in the GMT900 years. The L92 debuted in the 2007 Cadillac Escalade; engines built before April 1, 2006 carried AFM hardware that was never switched on, and later ones had none. For 2009 the engine became flex-fuel as the L9H, still without AFM. For 2010 GM added Active Fuel Management, creating the L94 used in the Escalade and Yukon Denali models. The 2007–2013 Sierra 1500 Denali is listed with the L92\/L9H family rather than the L94. From 2014 on, the trucks use the EcoTec3 6.2L L86, which has AFM.\u003c\/p\u003e\u003ch2\u003eWhere AFM came from\u003c\/h2\u003e\u003cp\u003eCylinder deactivation at GM goes back to the 1981 Cadillac V8-6-4. The current approach began as Displacement on Demand, announced in 2003 for the 2005 TrailBlazer EXT, Envoy XL and Envoy XUV 5.3L, then the front-drive 5.3L LS4 cars. Under the Active Fuel Management name it became common on Gen IV and EcoTec3 truck V8s. The 2010 Camaro SS automatic got it on the L99. In 2019, Dynamic Fuel Management replaced it on the new Silverado and Sierra 1500 V8s.\u003c\/p\u003e\u003ch2\u003eEngine data at a glance\u003c\/h2\u003e\u003cp\u003ePublished output and key features of the relevant engines. Exact ratings depend on the vehicle and model year:\u003c\/p\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eRPO code\u003c\/th\u003e\n\u003cth\u003eSize\u003c\/th\u003e\n\u003cth\u003ePower\u003c\/th\u003e\n\u003cth\u003eTorque\u003c\/th\u003e\n\u003cth\u003eCompression\u003c\/th\u003e\n\u003cth\u003eNotes\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eLY5\u003c\/td\u003e\n\u003ctd\u003e5.3L\u003c\/td\u003e\n\u003ctd\u003e315–320 hp\u003c\/td\u003e\n\u003ctd\u003e335–340 lb-ft\u003c\/td\u003e\n\u003ctd\u003e9.95:1\u003c\/td\u003e\n\u003ctd\u003eiron block, AFM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLC9\u003c\/td\u003e\n\u003ctd\u003e5.3L\u003c\/td\u003e\n\u003ctd\u003e315–320 hp\u003c\/td\u003e\n\u003ctd\u003e335 lb-ft\u003c\/td\u003e\n\u003ctd\u003e9.60:1 or 9.95:1\u003c\/td\u003e\n\u003ctd\u003ealuminum block, AFM, E85-capable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLMG\u003c\/td\u003e\n\u003ctd\u003e5.3L\u003c\/td\u003e\n\u003ctd\u003e315–320 hp\u003c\/td\u003e\n\u003ctd\u003e335–340 lb-ft\u003c\/td\u003e\n\u003ctd\u003e9.60:1\u003c\/td\u003e\n\u003ctd\u003eAFM, E85-capable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eL76\u003c\/td\u003e\n\u003ctd\u003e6.0L\u003c\/td\u003e\n\u003ctd\u003e348–367 hp\u003c\/td\u003e\n\u003ctd\u003e376–385 lb-ft\u003c\/td\u003e\n\u003ctd\u003e10.40:1\u003c\/td\u003e\n\u003ctd\u003ealuminum block, AFM, VVT on truck versions\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLFA\u003c\/td\u003e\n\u003ctd\u003e6.0L\u003c\/td\u003e\n\u003ctd\u003e332 hp\u003c\/td\u003e\n\u003ctd\u003e367 lb-ft\u003c\/td\u003e\n\u003ctd\u003e10.80:1\u003c\/td\u003e\n\u003ctd\u003ealuminum block, AFM, hybrid\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eLZ1\u003c\/td\u003e\n\u003ctd\u003e6.0L\u003c\/td\u003e\n\u003ctd\u003e332 hp\u003c\/td\u003e\n\u003ctd\u003e367 lb-ft\u003c\/td\u003e\n\u003ctd\u003e10.80:1\u003c\/td\u003e\n\u003ctd\u003ealuminum block, AFM, VVT, hybrid\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eL83\u003c\/td\u003e\n\u003ctd\u003e5.3L\u003c\/td\u003e\n\u003ctd\u003e355–376 hp\u003c\/td\u003e\n\u003ctd\u003e383–416 lb-ft\u003c\/td\u003e\n\u003ctd\u003e11.00:1\u003c\/td\u003e\n\u003ctd\u003ealuminum block, AFM, VVT, direct injection, E85-capable\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eL86\u003c\/td\u003e\n\u003ctd\u003e6.2L\u003c\/td\u003e\n\u003ctd\u003e420 hp\u003c\/td\u003e\n\u003ctd\u003e460 lb-ft\u003c\/td\u003e\n\u003ctd\u003e11.50:1\u003c\/td\u003e\n\u003ctd\u003ealuminum block, AFM, VVT, direct injection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch2\u003eThe hardware behind AFM\u003c\/h2\u003e\u003cp\u003eAn AFM engine has a solenoid valve assembly in the engine valley cover. Its solenoids send pressurized oil to special hydraulic roller lifters (supplied by Eaton and Delphi) on the deactivating cylinders, which then stop opening the valves. Because the system runs on oil pressure, oil quality matters: worn-out anti-foam additives, the wrong viscosity or overdue changes can delay the oil signal and upset the switching. The module stops the switching; the oil system still needs proper care.\u003c\/p\u003e\u003ch2\u003eModel background\u003c\/h2\u003e\u003cp\u003eGM's full-size trucks and SUVs from the 2007 model year rode on the GMT900 platform with Gen IV V8s. The 2014 Silverado 1500 and Sierra 1500, and the 2015 Tahoe, Suburban, Yukon and Escalade, moved to the K2XX platform with the EcoTec3 engines (4.3L LV3, 5.3L L83, 6.2L L86). Both generations used AFM on most gasoline V8s, so the engine code decides fitment more reliably than the model name.\u003c\/p\u003e\u003ch2\u003eQuick definitions\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eAFM:\u003c\/strong\u003e Active Fuel Management, GM's cylinder deactivation system on the engines covered here.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoD:\u003c\/strong\u003e Displacement on Demand, the original name for AFM.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eRPO code:\u003c\/strong\u003e GM's three-character option code; engine codes begin with L.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eSPID label:\u003c\/strong\u003e Service Parts Identification label listing the RPO codes on pre-2018 GM vehicles.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eVIN 8th digit:\u003c\/strong\u003e The VIN character that identifies the engine.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDFM:\u003c\/strong\u003e Dynamic Fuel Management, the system on 2019-on L84 and L87 engines that can deactivate cylinders individually.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eOBD-II port:\u003c\/strong\u003e The standard diagnostic connector under the dash on every US vehicle since 1996.\u003c\/p\u003e\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\u003ch3\u003eDo I need to remove it for an emissions test or scan tool?\u003c\/h3\u003e\u003cp\u003eYes. It uses the diagnostic port, so unplug it while the port is needed and plug it back in afterwards.\u003c\/p\u003e\u003ch3\u003eWill it fix lifter noise or misfires?\u003c\/h3\u003e\u003cp\u003eNo. Those are mechanical or electrical faults that need their own diagnosis and repair.\u003c\/p\u003e\u003ch3\u003eWhich GMC Yukon years and engines does it fit?\u003c\/h3\u003e\u003cp\u003eThe fitment table lists GMC Yukon 2007–2018 with 5.3L V8, 6.0L V8, 6.2L V8. Match your exact year and engine to a row before ordering.\u003c\/p\u003e\u003ch3\u003eDoes it plug into the OBD-II port on the GMC Yukon?\u003c\/h3\u003e\u003cp\u003eYes. It plugs into the OBD-II port under the dash. There is no wiring or splicing.\u003c\/p\u003e\u003ch3\u003eCan I go back to factory AFM?\u003c\/h3\u003e\u003cp\u003eYes. Unplug the module and the factory cylinder-deactivation strategy works again.\u003c\/p\u003e\u003ch3\u003eWill it add horsepower?\u003c\/h3\u003e\u003cp\u003eNo. It keeps all cylinders active; it does not change the engine tune.\u003c\/p\u003e\u003ch3\u003eDo I need it if my engine already has an AFM delete?\u003c\/h3\u003e\u003cp\u003eNo. An engine with the AFM hardware removed and a matching tune no longer deactivates cylinders, so the module has nothing to manage.\u003c\/p\u003e\u003ch3\u003eHow much fuel does AFM save?\u003c\/h3\u003e\u003cp\u003eEPA-test estimates published for GM's system are about 5.5–7.5%, with the benefit coming from light-load cruising. Keeping all cylinders active gives up part of that, depending on how you drive.\u003c\/p\u003e\u003ch3\u003eIs a tune or ECU reflash required?\u003c\/h3\u003e\u003cp\u003eNo. The module plugs into the OBD-II port and does not rewrite the engine computer's software.\u003c\/p\u003e\u003ch3\u003eHow do I tell which engine my GMC Yukon has?\u003c\/h3\u003e\u003cp\u003eCheck the 8th digit of the VIN or the RPO codes on the Service Parts Identification label (QR code on the door-pillar label on 2018 and newer GM models).\u003c\/p\u003e\u003ch3\u003eDoes it change anything when towing?\u003c\/h3\u003e\u003cp\u003eUnder heavy load, such as towing up a grade, AFM already keeps all cylinders running. The difference shows up during lighter cruising between climbs, where the engine no longer drops cylinders.\u003c\/p\u003e\u003ch3\u003eDoes it work on 2019 and newer trucks with Dynamic Fuel Management?\u003c\/h3\u003e\u003cp\u003eOnly the vehicles and engines in this listing's fitment table are covered. DFM on the 2019-on Silverado 1500 and Sierra 1500 (5.3L L84, 6.2L L87) is a different system, so do not assume coverage outside the table.\u003c\/p\u003e\u003ch2\u003eOrdering details\u003c\/h2\u003e\u003cp\u003eStandard shipping inside the lower 48 states costs nothing; allow 1–2 business days of handling plus 3–4 in transit. Returns need approval first and must be requested within 45 days. Approved returns are subject to a 20% restocking fee, with return shipping paid by the customer. A 3-year limited warranty applies. Email support@automotivebypass.com (Mon–Fri, 9–5 PST) with your VIN if you want a fitment check.\u003c\/p\u003e","brand":"Automotivebypass","offers":[{"title":"Default Title","offer_id":56493783384436,"sku":"RC-AFM-DFM-01-18","price":79.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1030\/8439\/2820\/files\/RC-AFM-DFM-01-18-1.jpg?v=1793172304","url":"https:\/\/automotivebypass.com\/products\/afm-dfm-vcm-disabler-gmc-yukon-2007-2018-afm-dfm-disabler","provider":"Automotivebypass","version":"1.0","type":"link"}