V8Lock™ AFM/DFM Disabler
V8Lock™ AFM/DFM Disabler
V8Lock™ AFM/DFM Disabler
V8Lock™ AFM/DFM Disabler
V8Lock™ AFM/DFM Disabler
V8Lock™ AFM/DFM Disabler
V8Lock™ AFM/DFM Disabler

4.8/5 from GM Owners 

V8Lock™ AFM/DFM Disabler

Keep Your V8 a V8


Stop unwanted AFM/DFM cylinder switching and keep your compatible GM engine in full-cylinder operation with one simple OBD-II plug-in.

Keeps Your GM V8 in Full-Cylinder Mode

Stops Unwanted AFM/DFM Cylinder Switching

Plug & Play Through OBD-II — No Tools

No Permanent ECU Tune — Fully Reversible

Secure Checkout

Free US Shipping

60-Day Risk-Free

VEHICLE COMPATIBILITY

WILL IT WORK WITH MY TRUCK?

Check your year, make, model and engine before ordering.

Chevrolet — 29 models

GMC — 13 models

Cadillac — 12 models

Buick — 7 models

Pontiac — 9 models

Holden — 10 models

Saab, Saturn, Isuzu & Suzuki — 8 models

THE FACTORY EXPERIENCE

FEEL YOUR TRUCK CONSTANTLY SWITCHING BETWEEN CYLINDER MODES?

AFM/DFM can reduce active cylinders during light-load driving, then bring them back when more power is needed. Some owners simply prefer a more consistent engine character.

V8

Full-cylinder operation

REDUCED CYLINDERS

Light-load cruising

V8

Power demand returns

Changing Exhaust Tone

A different sound as modes change.

Different Throttle Feel

Response may feel less consistent.

Unwanted Mode Switching

The vehicle decides when to deactivate.

Shudder-Like Sensation

Full-cylinder operation

THE V8 YOU PAID FOR

YOU BOUGHT A V8.
DRIVE IT LIKE ONE.

No constant cylinder-mode changes. No permanent tune. Just the consistent V8 character you wanted in the first place.

HOW IT WORKS

PLUG IT IN. KEEP FULL-CYLINDER OPERATION.

The module connects through your OBD-II port and, while connected, disables unwanted cylinder deactivation on compatible vehicles.

1. Plug Into OBD-II

Connect directly to the diagnostic port under the driver-side dashboard.

2. Module Communicates

The device works with the vehicle while connected — no permanent ECU flash required.

3. Full-Cylinder Driving

Enjoy a more consistent full-cylinder engine character while you drive.

SAME TRUCK. MORE CONSISTENT V8 CHARACTER.

FACTORY AFM/DFM

V8 → Reduced Cylinders → V8

Changing cylinder modes

Changing engine/exhaust character

Less consistent driving feel

No Permanent ECU Tune — Fully Reversible

FACTORY AFM/DFM

V8 → V8 → V8

Full-cylinder operation

Consistent throttle character

More predictable driving feel

No Permanent ECU Tune — Fully Reversible

KEEP MY V8 A V8 →

HOW IT WORKS

INSTALLED IN SECONDS.

No tools. No wiring. No complicated setup.

1. Plug Into OBD-II

Usually located below the driver-side dashboard.

2. PLUG IT IN

Connect the module directly to the vehicle's OBD-II port.

3. DRIVE

Start up and hit the road. Want factory operation back? Simply unplug it.

CORE BENEFITS

EVERYTHING YOU WANT. NOTHING YOU DON'T.

V8

Full-Cylinder Control

Keep compatible GM engines operating in full-cylinder mode while connected.

Smoother, Consistent Feel

Reduce unwanted changes in driving character from cylinder-mode switching.

3. DRIVE

Want factory operation back? Just unplug it.

No ECU Tune

No permanent ECU programming changes required.

No Tools

No cutting, wiring or engine teardown.

Set & Drive

Plug it into the OBD-II port and leave it connected during use.

VEHICLE-SPECIFIC PROOF

BUILT FOR GM OWNERS LIKE YOU.

2016 CHEVROLET SILVERADO 5.3L

“Plugged it in under the dash and that was it. The truck feels much more consistent on the highway.”

- Jason T.

2017 CHEVROLET TAHOE 5.3L

“Installation took seconds. I prefer the way it drives staying in full-cylinder operation.”

- Martin J.

GMC SIERRA 6.2L

“Exactly what I wanted. No tune and no trip to a shop — just plug it in and drive.”

- Jackie S.

FAQ

QUESTIONS? WE'VE GOT YOU.

What does an AFM/DFM disabler do?

It disables factory cylinder-deactivation operation on compatible GM vehicles while connected, helping the engine remain in full-cylinder operation.

Do I need to tune my ECU?

No permanent ECU tune is required. The module works through the OBD-II port.

Is installation difficult?

No. Locate the OBD-II port, plug the module in and drive. No special tools or wiring are required.

Is it permanent?

No. Unplug the module to return the vehicle to normal factory cylinder-management operation.

Will it work with my vehicle?

Compatibility depends on year, make, model and engine. Always verify compatibility before ordering.

Will it increase horsepower?

No. This is not a performance tune and is not marketed as a horsepower-adding device.

Will it improve fuel economy?

Fuel savings are not the purpose of this product. Factory AFM/DFM systems are designed partly around fuel-efficiency objectives.

GET MY AFM/DFM DISABLER →