{"nhtsa_id":11032363,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-05-06","date":"2026-05-05","document_id":"LI27.60-P-079083","mfr_campaign":null,"replaces":null,"component":"POWER TRAIN","mfr_system":null,"summary":"Complaint • Harsh 1-2, 2-3, and/or 3-4 shift • Jerky shifting • Jolting when accelerating from stop Cause Insufficient software application causing elevated K81/K27/B05 fill time adaptations and elevated torque adaptations for concerning shift. Note: Shift quality in E Performance models can be affected if the HV Battery state of charge (SOC) reaches 25% or below. Remedy Check VGS software level, and follow relevant remedy instructions. (see attachment) Vehicles with VGS software levels up to 22A: As of 1/28/2026, aftersales software improvement has been released for model years 2024-2025 GLC43 (A 001 902 20 34). This software has been implemented in production as of model year 2026. Please ensure your Xentry machine is up to date with the latest Add Ons and continue with the following steps: Note: ALL steps must be performed to rectify concern 1. Check for new VGS software, update if available 2. Check transmission oil level and correct, if necessary (transmission oil temperature > 60 °C) 3. Perform Xentry Valve Flushing procedure at least 3x 4. Perform resetting of deceleration values (VGS > Special Procedures > Special procedure > Resetting learned values Deceleration mode) 5. Perform a standstill adaptation, then read out new EEPROM data 6. Perform driving adaptation(s) while adhering to the below parameters for at least 20-30 miles 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 6-7 (adapts B05 for the 2-3 shift) Harsh 3-4 Perform a driving adaptation of 3-4 (adapts K27 directly) - See attached PDF for min/max torque, and RPM parameters - Transmission oil temperature > 30°C (>86°F) - Level track (no incline/decline) - Slippery drive program - Display the torque in the instrument cluster - Constant engine torque - Do not shift via paddle If the vehicle returns and already had ALL steps in this LI performed on a previous visit or has software level 23A and newer: Please submit a TIPS case to the Powertraininbox 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) - Detailed vehicle history of the complaint","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11032363-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11032363-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11032363","components":[{"id":"powertrain","name":"Transmission and driveline","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"MERCEDES-BENZ","model":"AMG GLC43","year_from":2026,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC43 4MATIC","year_from":2026,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC43 COUPE","year_from":2026,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC63 S E 4MATIC+","year_from":2026,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC63 S E 4MATIC+ COUPE","year_from":2026,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC43 4MATIC COUPE","year_from":2026,"year_to":2026,"match":null,"vehicle_ids":[]}],"as_of":"2026-10-19","note":"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.","attribution":[]}