Mercedes-Benz Anti-theft Protection Activated - Quick Fix Guide

Seeing "Anti-theft Protection Activated" on your Mercedes display? This message indicates that your NTG system has entered security lock mode and requires the correct NTG Anti-Theft PIN Code(also known as Mercedes Benz Command Code) to unlock.

This guide explains how to diagnose an "Anti-theft Protection Activated" message, identify the installed NTG unit, and use the original unit-specific Anti-Theft PIN with the required entry method.

What Does "Anti-theft Protection Activated" Mean?

Mercedes-Benz, like many premium car manufacturers, implements a security code system to prevent theft of their audio equipment. When the power supply to the radio is interrupted (such as when the battery is disconnected or the radio is removed), the system requires a unique code to reactivate. This deters thieves, as a stolen radio would be unusable without the correct code.

When You'll Need Your Radio Code

You'll typically need to enter your Mercedes radio code in these situations:

• After replacing your car battery
• Following electrical system repairs or maintenance
• When your radio displays "CODE" on the screen
• After purchasing a used Mercedes with a locked radio
• If the radio has been removed and reinstalled

Methods to Recover Your Mercedes Radio Code

There are several ways to retrieve your lost radio code. We'll cover each method in detail, starting with the easiest options.

Method 1: Check Your Vehicle Documentation

The simplest place to start is with your vehicle's documentation:

• Look in your owner's manual packet
• Check for a small radio code card (often wallet-sized)
• Examine the vehicle's service booklet
• Look inside the glove compartment for a sticker with the code

Mercedes often provides the radio code on a separate card for safekeeping. This card typically includes both the radio serial number and the corresponding code.

Method 2: Inspect the Radio Unit

In some cases, the code might be found on the radio itself:

• Remove the radio (consult your owner's manual for the proper procedure)
• Look for a sticker on the top, sides, or back of the unit
• The sticker may contain both the serial number and the security code

Note: Removing the radio yourself may void your warranty if your vehicle is still under warranty. Consider consulting a professional if you're unsure.

Method 3: Contact Your Mercedes-Benz Dealer

Your local Mercedes-Benz dealership can retrieve the code for you:

• Bring proof of ownership (vehicle registration, title, etc.)
• Provide your Vehicle Identification Number (VIN)
• The dealer will need the radio's serial number
• There may be a service fee for this assistance

This is a reliable method, but it can be time-consuming and potentially expensive.

Method 4: Use Our Online Code Retrieval Service

Our independent service is an online option for supported units:

• No need to visit a dealership
• Current estimated timing is shown before payment
• Often lower-priced than many alternatives; the checkout amount applies
• Compatibility depends on the installed unit and accurate identifiers

To use our service, you'll need your radio's serial number. We'll guide you through the process of locating this number in the next section.

How to Find Your Radio's Serial Number

Before you can recover your code, you'll need to find your radio's serial number:

For Most Mercedes Audio Systems:

1. Turn on the ignition (position II)
2. Press and hold the "i" button on your radio
3. While holding the "i" button, press and hold the "1" and "4" buttons simultaneously
4. The display should show the serial number (usually starting with "A" followed by numbers)

For COMAND Navigation Systems:

1. Press the "Phone" and "#" buttons simultaneously
2. Enter "1" "3" "8" using the keypad
3. The serial number should appear on the screen

If these methods don't work for your specific model, consult your owner's manual or contact us for assistance.

How to Enter Your Radio Code

Once you've retrieved your code, here's how to enter it:

For Standard Mercedes Radios:

1. Turn on the ignition (position II)
2. Turn on the radio
3. When "CODE" appears on the display, use the number buttons to enter your code
4. Press and hold the ">" button to confirm

For COMAND Navigation Systems:

1. Turn on the ignition
2. When prompted for the code, enter it using the number keypad
3. Press "OK" to confirm

Important: If you enter an incorrect code, you'll typically have three attempts before the system locks for a period of time (usually an hour). After this waiting period, you can try again.

Preventing Future Radio Code Issues

To avoid having to retrieve your radio code in the future:

• Write down your code and keep it in a secure location (not in the car)
• When having battery work done, consider using a memory saver device
• Inform your mechanic about the radio code requirement before electrical work
• Save a digital copy of your code in a secure password manager

Need Help Recovering Your Mercedes Radio Code?

If you're still having trouble retrieving your Mercedes radio code, review whether the installed unit is supported and whether professional code entry is required.

Review our online code service. For a supported unit, our independent service retrieves the original unit-specific code from the OEM code record using the submitted identifier; we are not Mercedes-Benz or an authorized dealership. The current checkout price applies.