2016-2019 Cadillac ATS Auto Start Stop Eliminator

This inline memory harness is for the 2016–2019 Cadillac ATS. It stores the last stop-start setting you chose, so if you turned Auto Stop/Start off on one drive, it stays off the next time you start the engine. It plugs in line with the factory connector named in the instructions. Both ends are factory-style plugs, so nothing is cut or spliced.

It does not delete the feature. Turning stop-start back on is the same button press as before, and the module will remember that too. Removing it returns the vehicle to its original default.

Which Cadillac ATS models it fits

Listed applications (each row is a 100% fitment match for the factory connector this part uses):

• Cadillac ATS: 2016–2019

For reference, the Cadillac ATS in these years is a compact sport sedan offered with 2.0L turbo four-cylinder and 3.6L V6 engines, most of the driving it sees is daily commuting, ride-share duty and highway travel. The listing is written around the first-generation (2013-2019) ATS. The table does not separate trims; what matters is that the vehicle has factory stop-start and the connector shown in the photos.

How Auto Stop/Start behaves from the factory

Each start of the Cadillac ATS begins with Auto Stop/Start enabled. The switch on the dash can disable it, but only until the key is cycled. This module records the switch position and repeats it after the restart, which is the entire job it does.

Why owners turn it off

Pressing the same button on every drive is what wears on owners. People who tow, plow, idle in pickup lines, creep through heavy traffic or simply want the engine running at a light end up making the same press dozens of times a week. On the Cadillac ATS, the module turns that into a one-time choice you can still change whenever you want.

Keep the battery healthy

If the stop-start indicator shows the system as unavailable, test the battery before anything else. On stop-start vehicles that is the most common cause. A replacement should match the original specification (AGM or EFB), and some manufacturers call for a battery monitor reset after the swap.

Connecting it

It plugs in line with the factory connector named in the instructions. Both ends are factory-style plugs, so nothing is cut or spliced. The instructions show the connector for this application; compare it with the product photos before starting. Turn the vehicle off, make the connection, fix the module in place, and test with two or three key cycles.

When the engine will not auto-stop anyway

The factory system will skip an auto stop for many reasons: battery charge below its threshold, cold coolant, high climate-control load, a steep grade, the hood or driver door open, or a 4WD or tow mode on vehicles that have them. Those checks stay in control after this module is installed. It does not force stops and it does not bypass any of those safety inputs.

What the module does and does not do

• Fuel use changes only the way it would if you pressed the off button yourself.
• Does not disable warning lights or diagnostic functions.
• Carries your stop-start choice over to the next drive.
• Comes out in the same way it went in, with nothing cut.

Before blaming the module

A warning light that appears after installation usually means a connector is not fully seated. Switch the ignition off, reseat both ends until the locks click, and test again. If the light stays on, remove the module and confirm the vehicle is fault-free on its own before contacting support.

Confirm these points

• Model year and model match a row in the table above (2016–2019 Cadillac ATS).
• Your Cadillac ATS has the factory stop-start button. Base trims or engines without stop-start have nothing for the module to remember.
• The battery and charging system test good and no warning lights are on.
• The connector at your install point matches the one in the product photos.
• No aftermarket remote start, alarm or gateway bypass is wired into the same circuit. If one is, email support before ordering.
• If you are unsure, send your VIN to support@automotivebypass.com and we will confirm fitment.

Warranty and returns

We ship free within the contiguous United States (1–2 business days to dispatch, roughly 3–4 business days in transit). If it turns out to be the wrong part, request a return authorization within 45 days; returns carry a 20% restocking fee and return postage is on the buyer. Coverage is a 3-year limited warranty. Questions go to support@automotivebypass.com, weekdays 9 a.m. to 5 p.m. PST.