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Service bulletin LI27.60-P-079083

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id11023043
Published by NHTSA2025-09-09
Manufacturer's numberLI27.60-P-079083
Manufacturer's date2025-09-08
NHTSA componentPOWER TRAIN

NHTSA's summary

Complaint • Harsh 1-2, 2-3, and/or 3-4 shift • Jerky shifting • Jolting when accelerating from stop Cause Insufficient powertrain software Remedy Please continue with the following: 1. Check transmission oil level and correct, if necessary (transmission oil temperature > 60 °C) 2. Perform Xentry Valve Flushing procedure at least 3x 3. Perform a standstill adaptation, then read out new EEPROM data If the concern is still present: 4. Perform driving adaptation(s) below 5x for harsh gear shift using the following criteria: Note: There is no menu in Xentry for this procedure. We recommend displaying the torque in the instrument cluster. If all below parameters are met at the time the shift, a driving adaptation will automatically occur. Harsh 1-2 Perform a driving adaptation of 4-5 (adapts K81 for the 1-2 shift) Harsh 2-3 Perform a driving adaptation of 2-3 (adapts B05 directly) Harsh 3-4 Perform a driving adaptation of 3-4 (adapts K27 directly) - Level track (no incline/decline) - Slippery drive program - Display the torque in the instrument cluster: The torque must be between 100 and 250 Nm (about 184 ft lbs), preferably closer to the maximum torque - Constant engine torque - Engine speed below 2500 rpm - Do not shift via paddle If the concern still persists, please submit a TIPS case to the Powertrain inbox and ensure the following is included: - Initial Quick Test w/ Freeze Frame Data - VGS Control Unit Log - Initial EEPROM (before any adaptations or Xentry procedures were performed) - EEPROM data after all driving adaptations

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Transmission and driveline

Vehicles listed
MERCEDES-BENZ AMG GLC432024
MERCEDES-BENZ AMG GLC43 4MATIC COUPE2024 to 2025

Listing a model year does not mean every vehicle of it is concerned: the document says which.