Cadillac CT6 2016-2018 3.0L/3.6L V6 AFM/DFM Disabler

For the 2016–2018 Cadillac CT6: an OBD-II plug-in module that stops the engine from switching into cylinder-deactivation mode. The engine stays on all cylinders during cruising and light throttle, where AFM would normally shut half of them down. Installation is plugging it in. Nothing is spliced, flashed or removed from the engine, and the factory system resumes as soon as the module is unplugged.

Covered applications

Listed applications, each a 100% fitment match:

• 2016–2018 Cadillac CT6: 3.0L V6 / 3.6L V6

GM used several V6 families in these years. Before ordering, confirm from your RPO label or VIN that your engine is the one listed and that it is equipped with cylinder deactivation; if in doubt, send the VIN to support.

How Active Fuel Management operates

Cylinder deactivation shuts off fuel and valve operation on part of the engine at light load, then brings those cylinders back when you need power. The engine computer decides when to switch based on load, speed and other inputs. This module works through the OBD-II port to keep the computer from choosing the reduced mode.

Plug-in module vs. a mechanical AFM delete

A mechanical AFM delete swaps the deactivating lifters (and often the camshaft and lifter oil manifold) for non-AFM parts and requires a tune afterwards. A tune alone can switch AFM off in software. This module works through the OBD-II port instead, so the engine hardware and its calibration stay stock. That makes it the easiest option to reverse, and the right one only when the engine is mechanically healthy.

Practical notes

Because 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.

What changes when you drive

Expect steadier behavior at part throttle and no change at wide-open throttle. Towing and hill climbing were already mostly done on all cylinders, so the biggest change is during relaxed cruising. Average fuel economy may drop slightly depending on how much of your driving is light-load highway time.

What owners are after

A Cadillac CT6 with AFM switches modes many times on a typical drive. Some owners never notice; others feel it every time. If you are in the second group, or you tow and want steady behavior, keeping all cylinders active is the simplest answer. Fuel use at light cruise will usually rise a little, since that is where AFM saves fuel.

Oil and maintenance

Oil level and quality are worth watching on any AFM engine, because the deactivation hardware is hydraulic. Check the dipstick at fuel stops on high-mileage engines, follow GM's specified oil grade, and address oil-pressure warnings immediately. None of that changes with the module installed.

Before installing

This module prevents mode switching. It does not repair anything. If the engine already has a ticking lifter, misfire codes, low oil pressure or high oil consumption, have it diagnosed before relying on the module. Those symptoms need a mechanical repair, and keeping AFM off will not reverse damage that has already happened.

Fitment check

• Your model year, model and engine match a row in the table (2016–2018 Cadillac CT6).
• The 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).
• The engine runs cleanly with no stored misfire or AFM codes.
• Engine swaps, custom tunes and replaced ECUs need a fitment check from support before ordering.
• Questions: support@automotivebypass.com with your VIN.

Shipping, returns and warranty

Free standard shipping covers the contiguous US, with dispatch in 1–2 business days and 3–4 days on the road after that. You have 45 days to request a return (pre-approval required, 20% restocking fee, buyer-paid return shipping). The module is backed by a 3-year limited warranty. For order or fitment questions, write to support@automotivebypass.com between 9 and 5 Pacific, Monday through Friday.