2021 Mercedes-Benz AMG GT Rear Spoiler Inoperative Fault

Symptoms

Owners of the 2021 Mercedes-Benz AMG GT may experience a condition where the rear spoiler sporadically remains in an opened position or fails to extend. During this time, a "fault message appears in the instrument cluster," and the spoiler cannot be manually retracted using its control button. Typically, the spoiler's function is re-established after an ignition reset, and the fault message disappears.

Affected Control Unit

The issue is associated with the N145/1 - AMG DRIVE UNIT, also referred to as AMG DRVU or DRVU_NG.

Causes

Mercedes-Benz has identified two primary causes for the 2021 Mercedes-Benz AMG GT rear spoiler inoperative condition:

• Coding of the AMG DRIVE UNIT: Incorrect coding may prevent the unit from properly recognizing the Hall sensor when retracting the rear spoiler.
• Hardware tolerances / hardware wear: Mechanical variations or wear in components can contribute to the malfunction.

Repair Procedure Summary

Addressing the 2021 Mercedes-Benz AMG GT rear spoiler inoperative issue involves a multi-step diagnostic and repair process performed by a qualified technician.

1. Initial Diagnosis: Technicians first check the current actual values under the path "DRVU -> Actual values -> Rear wing sensor system." If all values are within the specified green range, the vehicle undergoes a final inspection and test drive before being returned to the customer.

2. Software Update or SCN Coding: If the actual values are outside the specified range (red) or the initial inspection is not satisfactory, the technician will check for new software for the AMG DRIVE UNIT. If available, a software update is performed. If the vehicle already has the most current software version, SCN coding of the AMG DRIVE UNIT is conducted. The specific software versions for the AMG Drive Unit N145/1 are:

   • Up to YoM 19/2: Software A001 902 6208
   • From YoM 20/1 up to YoM 20/2: Software A001 902 6108
   • From YoM 21/1: Software A001 902 6008

3. Rear Spoiler Initialization: After software updates or SCN coding, the rear spoiler is initialized up to five times until all values are within the target green range.

4. Mechanical Inspection (if needed): If the issue persists, the screw connection of the rear spoiler adjuster is checked for tight seating.

5. Loose Screw Repair: If screws are found to be loose, the following steps are performed:

   • Unscrew the screw with a Torx TX25 screwdriver from the housing guide.
   • Dip the screw in Loctite 603, ensuring at least three threads are coated.
   • Screw the screw back into the housing guide with 2 Nm of torque.
   • Initialize the rear spoiler after the Loctite has cured.
   • Perform a final inspection and test drive.

6. Further Investigation: If the screws are tight and the problem remains unresolved, a TIPS case is created. This case requires detailed information, including when the fault message appears (speed, acceleration/braking, automatic mode), whether the problem is sporadic or continuous, if the fault message disappears after an ignition reset, and if the fault is reproducible.

Required Tools or Parts

• Loctite 603
• Torx TX25 screwdriver

Important Warnings

When applying Loctite 603 during the loose screw repair, it is critical to note that the product is finger-tight after 8 minutes but requires 24 hours to fully cure. The rear spoiler should be initialized only after the curing time has passed.

Owner Action

If your 2021 Mercedes-Benz AMG GT is experiencing a rear spoiler inoperative condition or displaying a "fault message appears in the instrument cluster," it is recommended to schedule an appointment with an authorized Mercedes-Benz service center. Technicians have the necessary tools and diagnostic procedures to accurately identify and resolve the issue according to the manufacturer's guidelines.

Source: NHTSA ID 11010445