AFM/DFM Disabler & Auto Start/Stop Eliminator for 2005-2025 GM

In this review the focus is on a compact plug-and-play device that targets two persistent nuisances in many GM trucks, SUVs and cars: cylinder deactivation and engine auto stop. The reviewer found it best suited to owners who want a constant V8 feel and to eliminate the factory Start/Stop system without cutting wires or installing hardware under the hood. Installation is simply an OBDII plug-in and the unit can run standalone, with an optional smartphone control for those who want to toggle functions or revert to factory settings.

Key Features

• Vehicle compatibility: Works with a wide range of GM models including 2022-2024 SUVs and 2022-2025 trucks plus supported 10-speed transmission vehicles, so buyers can check the model list for fit before purchase.
• AFM/DFM disabler: Forces Full-Time V8 mode so the engine fires on all cylinders continuously, restoring the traditional V8 operation for drivers who dislike cylinder deactivation.
• Start/Stop disabler: Eliminates the factory Auto Start/Stop behavior so the engine stays running when desired, useful in stop-and-go traffic or when uninterrupted climate control is needed.
• Plug-and-play operation: Stand-alone functionality means the device works immediately when plugged into the OBDII port without requiring an app for basic AFM/DFM and Start/Stop disabling.
• Easy installation: Installation is noninvasive via the OBDII port, avoiding any modification to engine components and lowering the risk of installation damage.
• Optional smartphone app: An app is available for those who want on-the-fly control and the ability to revert to factory conditions without unplugging the unit.

Who It's For

This device is aimed at GM owners who are bothered by cylinder deactivation or automatic engine shutoff and prefer a full-time V8 experience or constant engine operation for towing, hauling or comfort. It is especially relevant for drivers of supported 2022-2025 trucks and 2022-2024 SUVs who want a simple, reversible fix without dealer programming.

Those who should look elsewhere include drivers prioritizing every last bit of factory fuel economy or who need guaranteed compatibility for an uncommon model not listed in the supported vehicles. Also expect mixed results on fuel economy and other interactions; some owners reported changes in mpg or behavior, so fleet or efficiency-focused buyers should be cautious.

Pros & Cons

Pros

• Easy plug-in installation via OBDII means minimal effort and no engine compartment work.
• Reliable full-time V8 mode that disables AFM/DFM for a constant engine feel.
• Optional smartphone control provides flexibility to revert to factory settings when needed.
• Stand-alone functionality works without an app for straightforward disabling of Start/Stop.

Cons

• Compatibility is broad but not universal; buyers must verify their vehicle on the supported list.
• Some customers reported mixed real-world effects on fuel economy and occasional loss of functionality over time.

Specifications

Brand	Carbyte
Function	AFM/DFM disabler and Auto Start/Stop eliminator
Compatibility	GM 2005-2024 and select 2025 vehicles; includes 2022-2024 SUVs and 2022-2025 trucks and certain 10-speed models
Installation	Plug into OBDII port, no engine wiring required
Operation	Stand-alone plug-and-play; optional smartphone app for control
Mode	Full-Time V8 mode for AFM/DFM disabling

Our Verdict

For GM owners seeking a reversible, noninvasive way to stop cylinder deactivation and the Start/Stop function, this plug-in eliminator offers clear value and convenience. It is an affordable solution for drivers who prioritize engine feel and uninterrupted operation, though buyers should verify vehicle support and be aware that fuel economy results may vary in real use.

Frequently Asked Questions

Will this work without an app?
Yes, the device functions in stand-alone mode when plugged into the OBDII port and does not require the app for basic AFM/DFM and Start/Stop disabling.

Is installation permanent or reversible?
Installation is reversible: the unit plugs into the OBDII port and can be unplugged to restore original factory operation, and the app can also revert settings if desired.

Does it affect fuel economy?
Some users report mixed effects on fuel economy, including occasional drops in city mpg, so expect variable results depending on driving patterns and vehicle setup.