Push Start Stop Button Replacement for Mercedes M-Class W166 (2012 to 2014)

Push Start/Stop Button Replacement for Mercedes M-Class W166 (2012–2014)

The M-Class W166 replaced the W164 with a more refined cabin, new technology, and a bolder design language. At the heart of that technology suite is the KEYLESS-GO push-button start — a feature that, in the W166, became central to the driving experience rather than an optional extra. After several years of daily use, the button's factory finish shows the familiar signs: a worn centre face and a chrome ring that has lost its original lustre.

This direct replacement unit restores the button to original condition and costs a fraction of what a dealer would charge.

Looking to upgrade the interior of your car? Also visit the Mercedes section of our aftermarket parts shop.

Compatible Mercedes Models

Mercedes-Benz M-Class (W166) – 2012 to 2014

Mercedes-Benz ML 350 (W166) – 2012 to 2014

Fits W166 vehicles with factory KEYLESS-GO push-button start. Verify your button style against the product images before ordering.

Refined Cabin, Realistic Wear

The W166 interior was a significant step forward for the M-Class — better materials, a more coherent layout, and a premium feel that held up well in the early years. The KEYLESS-GO start button, however, is a high-contact surface. It is used every time the vehicle moves. Over 100,000+ presses across a decade of ownership, the button cap surface develops visible wear at the contact point, and the chrome surround picks up micro-scratches from key fobs, jewellery, and sleeve contact.

This is normal wear for a component at this price point. The correct response is a direct replacement, not a cleaning attempt.

What the Replacement Covers

The complete outer switch assembly — button cap, chrome ring, and retention hardware — as a pre-assembled unit ready to plug in. No electronics modification required.

Installation

Access the rear of the button, disconnect the plug, release the retention clip, and remove. Fit the replacement, reconnect, and test. The process takes 10 to 15 minutes and requires no dashboard removal.

Why This Replacement Is Worth It

Complete button unit — cap, chrome ring, and mounting included

Targeted fix for the W166's most frequently worn interior component

No KEYLESS-GO recoding — the system operates as standard immediately

Significant saving versus a Mercedes dealer replacement

Explore all parts and accessories for Mercedes, browse our full range of replacement interior buttons and controls, and discover more in our interior trims collection.

About Euro Premium Parts

Welcome to Euro Premium Parts, your trusted source for high-quality accessories and upgrades for BMW, Audi, Volkswagen, and Mercedes-Benz.

We started this store out of a genuine passion for European cars and a simple goal: make it easier for enthusiasts to find reliable, plug-and-play parts that fit perfectly and offer great value for money.

Our Mission

Our mission is to simplify the way you enhance your car.
Every product in our catalog is carefully preselected for its quality, fitment, and overall reliability, so you don’t have to waste time searching through endless listings.
All our items are plug & play, easy to install, and backed by a 1-year warranty.
And because great service shouldn’t come with extra fees, shipping is always free.

A Team of Car Lovers You Can Rely On

Euro Premium Parts is built and managed by car enthusiasts who understand what drivers expect when upgrading their vehicles.
We know how frustrating it can be to deal with compatibility or installation issues, which is why our support team is available to help every step of the way.
Our goal is to make each purchase smooth, transparent, and worry-free.

Why Drivers Choose Us

- Products chosen for quality and compatibility

- Free shipping on all orders

- 1-year warranty on every product

- Helpful and responsive customer support

- Straightforward, plug & play installation

There are plenty of online stores selling car parts, but few focus on reliability, compatibility, and customer service the way we do.

Built Around Passion and Trust

Whether you drive a sporty coupe, a luxury sedan, or a modern SUV, our catalog is designed to help you customize and enhance your car with confidence.
We’re constantly updating our selection based on what our customers want most, staying true to our commitment to quality and simplicity.

Your Partner in Automotive Style and Performance

When you shop at Euro Premium Parts, you’re choosing more than just products — you’re choosing a team that values quality, reliability, and honest service.
Every order is handled with care, and every customer matters.

Upgrade with confidence. Drive with pride.
Euro Premium Parts — European excellence, delivered.