GM Cylinder Deactivation (AFM/DFM) Issues with Engine Codes

General Motors AFM/DFM engines are identified by RPO codes. These engines have been linked to lifter collapse, oil consumption, and timing chain wear across trucks, SUVs, and sedans.

Engines Affected

Years Make Model Engine Engine Code (RPO) Notes
Years Make Model Engine Engine Code (RPO) Notes
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Chevrolet Silverado 1500, Tahoe, Suburban 5.3L V8 AFM LMG, LC9, L83 Collapsed lifters, oil consumption, misfires
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 GMC Sierra 1500, Yukon, Yukon XL 5.3L V8 AFM LMG, LC9, L83 Same issues as Chevrolet applications
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Cadillac Escalade, Escalade ESV 5.3L / 6.2L V8 AFM LMG, L99, L86 Oil consumption, lifter collapse
2007 2008 2009 2010 2011 2012 2013 Chevrolet Silverado HD, Suburban 2500 6.0L V8 AFM L76, L77 Timing chain wear, lifter collapse
2007 2008 2009 2010 2011 2012 2013 GMC Sierra HD, Yukon XL 2500 6.0L V8 AFM L76, L77 Same AFM-related failures
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Chevrolet Silverado 1500, Tahoe, Suburban 6.2L V8 AFM L99, L86 Oil consumption, lifter collapse
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 GMC Sierra 1500, Yukon Denali 6.2L V8 AFM L99, L86 Same AFM-related failures
2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Cadillac Escalade 6.2L V8 AFM L99, L86 Oil consumption, lifter collapse
2008 2009 2010 2011 2012 2013 2014 2015 2016 Chevrolet Impala, Traverse, Camaro 3.6L V6 AFM LLT, LFX Oil consumption, timing chain stretch
2008 2009 2010 2011 2012 2013 2014 2015 2016 Buick LaCrosse, Enclave 3.6L V6 AFM LLT, LFX Same AFM-related failures
2008 2009 2010 2011 2012 2013 2014 2015 2016 Cadillac CTS, SRX 3.6L V6 AFM LLT, LFX Oil consumption, timing chain wear
2019 2020 2021 2022 2023 2024 2025 Chevrolet Silverado 1500 5.3L / 6.2L V8 DFM L84, L87 Improved system, but lifter failures still reported
2019 2020 2021 2022 2023 2024 2025 GMC Sierra 1500 5.3L / 6.2L V8 DFM L84, L87 Same issues as Chevrolet applications

Summary

GM’s AFM/DFM engines — especially the 5.3L V8 (LMG, LC9, L83, L84) — are notorious for lifter collapse, oil consumption, and timing chain wear. These issues affect Chevrolet, GMC, Cadillac, and Buick models across trucks, SUVs, and sedans from 2007 to present.