2021 Mercedes-Benz AMG GT Unintentional Tailgate Opening

Symptoms of Unintentional Tailgate Opening

Owners of affected Mercedes-Benz vehicles, including the 2021 Mercedes-Benz AMG GT, may experience the tailgate opening without intending to. This issue is often described as the "Trunk lid/liftgate > Jumps open" or the "Tailgate opens unintentionally" in diagnostic reports. This can occur when the vehicle key is stored in a pocket or handbag, leading to inadvertent activation of the tailgate release button.

The symptom is specifically related to the tailgate or trunk lid unexpectedly opening, which can be inconvenient or potentially unsafe if the vehicle is unattended or in motion. The issue is not indicative of a mechanical failure of the tailgate itself, but rather an unintended command from the vehicle's key.

Cause of the Unintended Tailgate Operation

The primary cause of the 2021 Mercedes-Benz AMG GT unintentional tailgate opening is the accidental or unnoticed activation of the tailgate release button on the vehicle key. Modern vehicle keys often have buttons that can be pressed inadvertently when the key is carried in a tight space, such as a trouser pocket, or jostled within a handbag. This accidental "long press" on the key's button triggers the tailgate to open.

This design characteristic, while convenient for intentional use, can lead to frustration and concern for owners when the tailgate opens unexpectedly. The issue is prevalent across vehicles equipped with 6th, 7th, and 8th generation Mercedes-Benz keys.

Repair Procedure Summary

To resolve the 2021 Mercedes-Benz AMG GT unintentional tailgate opening, Mercedes-Benz has issued a technical service bulletin outlining a recoding procedure for the vehicle keys. This procedure modifies the key's functionality so that the tailgate no longer opens with a single long press, but instead requires a double-click on the button.

The repair involves several steps performed by a qualified technician:

1. Add AO Code O19: The first step is to add the AO code O19 (Oscar, not zero) in the VeDoc system. This code signifies the modification for the key's tailgate function.
2. Perform SCN Coding: Following the addition of the AO code, the Electronic Ignition Switch (EZS N73) module requires SCN (Software Calibration Number) coding. This process ensures the new key functionality is correctly integrated into the vehicle's electronic system.
3. Deactivate and Reactivate Vehicle Keys: Each vehicle key must be deactivated. A successful deactivation is indicated by the key's LED lighting up twice briefly, then once for a longer period.
4. Key Repositioning and Ignition Activation: After deactivation, the key must be placed on the key symbol located in the storage compartment. For model series 167, this storage compartment is found in the armrest. While the key is positioned, the ignition must be switched on. It is crucial that all other vehicle keys are kept outside the vehicle during this step to ensure correct data transfer.
5. Repeat for All Keys: Steps 3 and 4 must be performed successively for every vehicle key associated with the vehicle to ensure all keys are updated with the new double-click functionality.

This recoding ensures that the tailgate only opens when the owner deliberately double-clicks the button, preventing accidental activations.

Important Owner Information

Mercedes-Benz has specified that the costs for this adaptation, which resolves the 2021 Mercedes-Benz AMG GT unintentional tailgate issue, are to be borne by the customer. This means that owners will likely be responsible for the labor charges associated with the key recoding procedure at a dealership or authorized service center. This update differs from a recall, as it addresses a convenience and potential nuisance issue rather than a safety defect requiring a manufacturer-funded remedy.

The SCN coding process for the EZS is critical and requires specific conditions for correct data transfer to the vehicle key. Only one vehicle key should be present in the vehicle, and it must be deactivated and correctly positioned on the marking in the storage compartment during the data transfer.

Required Tools or Parts

The resolution for the unintentional tailgate opening involves software updates and recoding rather than replacement parts. Technicians will utilize:

• VeDoc System: To add the AO code O19.
• SCN Coding Equipment: For performing the Software Calibration Number coding on the EZS N73 module.
• Vehicle Keys: The existing 6th, 7th, and 8th generation vehicle keys are recoded. For keys up to modification year 22/1, the deactivation process involves pressing and holding the locking button while double-clicking on the release tab.

Owner Action

If you own a 2021 Mercedes-Benz AMG GT and are experiencing the tailgate opening unintentionally, you should contact your authorized Mercedes-Benz dealership. Explain the symptom of your 2021 Mercedes-Benz AMG GT unintentional tailgate operation. The dealership can perform the necessary key recoding procedure as outlined in Technical Service Bulletin LI72.20-P-075746. Be prepared for potential charges for this service, as Mercedes-Benz indicates that the cost for this adaptation is the owner's responsibility.

NHTSA ID: 10231032