2021 Mercedes-Benz AMG GT Steering Column Noises TSB

Mercedes-Benz has released Technical Service Bulletin (TSB) LI46.10-P-077314, dated January 22, 2024, to help diagnose and resolve various noises emanating from the steering column area in vehicles from model year 2019 onwards, including the 2021 Mercedes-Benz AMG GT. Owners may experience sounds such as grinding, squealing, or cracking during steering maneuvers.

This TSB provides a structured approach for technicians to identify the source of these noises, particularly focusing on the steering column switch module (MRSM/SCCM) and the steering wheel itself. While the exact cause is listed as "under analysis," the bulletin outlines specific diagnostic and repair steps to address customer complaints regarding "Mercedes-Benz AMG GT steering noises."

Symptoms of Steering Column Noise

Owners of affected 2021 Mercedes-Benz AMG GT vehicles may notice distinct noises coming from the steering column area when turning the steering wheel. These sounds are often described as:

• "Noises in the steering column area when steering"
• "Chassis/suspension > Steering system > Noises > Dragging/squealing"
• "Chassis/suspension > Steering system > Noises > Cracking"

Mercedes-Benz provides example media files to help technicians identify the specific types of noise: "MRSM-Schleifgeräusch_SCCM-GrindingNoises.MOV" for noises caused by the steering column switch module (MRSM/SCCM), and "Lenkrad-Schleifgeräusch_SteeringWheel-GrindingNoises.mp4" for noises caused by the steering wheel. These noises can originate either from the driver's footwell area or specifically from the steering column switch module (MRSM/SCCM) location.

Important Warnings and Notes

Technicians and owners should be aware of the following critical information from the TSB:

• MRSM/SCCM Installation: "When installing the MRSM/SCCM, make sure that no damage occurs!"
• Steering Wheel Noise: "If the noise is due to the steering wheel (see attachment 'Lenkrad-Schleifgeräusch_SteeringWheel-GrindingNoises.mp4'), please use LI46.10-P-077313." This indicates a separate bulletin exists for steering wheel-specific noises.
• Component Positioning: "Only disassemble and mount all component parts in the 'straight-ahead position' (see also WIS)." This ensures proper alignment during service.
• Warranty Claims: "Please refer to this LI in the 'Notes' section of the warranty claim!" This is crucial for proper documentation of the repair under warranty.

Fault Codes and Damage Codes

While this TSB does not list specific diagnostic trouble codes (DTCs), it references a particular damage code for warranty claims related to this issue:

• Damage Code: 5360036
  • Description: "53600: steering column switch module 36: noise"

This code helps technicians properly document and process repairs for "Mercedes-Benz AMG GT steering noises" associated with the MRSM/SCCM.

Diagnosis and Repair Procedure Summary

Diagnosing the source of the 2021 Mercedes-Benz AMG GT steering noises involves pinpointing the exact location of the sound. Technicians are instructed to determine if the noises are coming from the driver's footwell or the steering column switch module (MRSM/SCCM) area.

If the noises are suspected to originate from the MRSM/SCCM, the following diagnostic and repair steps are recommended:

1. Initial Alignment Check: Loosen the screws of the MRSM/SCCM and the steering wheel. Then, re-align the MRSM/SCCM and re-fasten the screws according to the Workshop Information System (WIS) procedures. This step aims to resolve noises caused by potential stress points at the MRSM/SCCM.
2. Diagnostic Module Swap: If the noises persist after the re-alignment, the MRSM/SCCM should be temporarily swapped into a known good vehicle (a "donor vehicle") that does not exhibit any noise complaints.
   • Outcome 1 (MRSM/SCCM is the cause): If the original MRSM/SCCM, when installed in the donor vehicle, now causes noises in that vehicle, then the MRSM/SCCM is confirmed to be faulty and can be replaced.
   • Outcome 2 (MRSM/SCCM is not the cause): If the original MRSM/SCCM, when installed in the donor vehicle, does not cause noises, and noises also occur in the customer vehicle with the MRSM/SCCM from the reference vehicle, then the MRSM/SCCM is not the cause and must not be replaced. Further diagnosis would be required to find the actual source of the "Mercedes-Benz AMG GT steering noises."

Required Tools and WIS References

Technicians will need access to the Mercedes-Benz Workshop Information System (WIS) for detailed removal and installation procedures. Specific WIS document numbers referenced include:

• AR54.25-P-2802ME: For removing and installing the steering column module (BR167).
• AR54.25-P-2812S: For removing and installing the steering column switch module (BR223).
• AR54.25-P-2812WT: For removing and installing the steering column switch module on Model series 206, 214, and 254.

Owner Action

If your 2021 Mercedes-Benz AMG GT is exhibiting grinding, squealing, or cracking noises from the steering column, it is recommended to schedule an appointment with an authorized Mercedes-Benz service center. Technicians will utilize TSB LI46.10-P-077314 to accurately diagnose the issue and perform the necessary adjustments or replacements. Since this is a technical bulletin, repairs performed under its guidance are typically covered by the vehicle's warranty if applicable.

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Source: NHTSA ID: 10249495