Cadillac XTS 2013-2018 3.6L V6 AFM/DFM Disabler

Fits the 2013–2018 Cadillac XTS. The module connects at the OBD-II port and keeps GM's cylinder deactivation from switching on, which means steady all-cylinder operation instead of repeated changes between full and partial mode. 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.

Vehicles, years and engines

Each row below is listed as a 100% fitment match:

• 2013–2018 Cadillac XTS: 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 GM cylinder deactivation works

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.

What to expect on the road

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.

Oil and maintenance

AFM lifters and the solenoids that control them run on engine oil pressure. Keeping the oil at the right level, using the grade GM specifies on the oil filler cap or in the owner's manual, and changing it on schedule matters whether or not AFM is active. The module changes when cylinders deactivate; it does not change the oiling system.

Check the engine first

Scan for stored codes before you plug it in. Misfire codes on the deactivation cylinders, an AFM solenoid circuit code, or a lifter noise are signs of an existing problem that should be repaired first. The module is meant for a healthy engine where you simply do not want cylinder deactivation.

Living with it

Leave it in the port for everyday driving. When the vehicle goes in for service or an emissions check, remove it so the shop has normal access to the diagnostic connector, then reinstall it.

Reasons to keep all cylinders running

A Cadillac XTS 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.

Module, tune or delete kit

Owners 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.

How to confirm your engine code

• Your model year, model and engine match a row in the table (2013–2018 Cadillac XTS).
• Find your engine code. On GM vehicles before the 2018 model year, the Service Parts Identification label (usually inside the glovebox on these trucks and SUVs) lists the three-character RPO codes, and the engine code starts with L. From 2018, GM moved that data into a QR code on the certification label on the driver-side door pillar. The 8th character of the VIN also identifies the engine.
• The engine runs cleanly with no stored misfire or AFM codes.
• If the vehicle has an engine swap, an aftermarket tune or a replacement engine computer, contact support first.
• Questions: support@automotivebypass.com with your VIN.

Shipping and support

Standard 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.