# Service bulletin LI27.19\-P\-080823

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.

- Type: Service bulletin
- NHTSA id: 11035713
- Published by NHTSA: 2026\-08\-05
- Manufacturer's number: LI27.19\-P\-080823
- Manufacturer's date: 2026\-08\-04
- NHTSA component: POWER TRAIN

## NHTSA's summary

Complaint Customers may report one or more of the following: • Transmission malfunction message • Check engine light illuminated • Shifts into N • Concern disappears after ignition cycle When performing a quick test, the following fault code is stored in Y3/14 \- Transmission control for 8\-speed dual\-clutch transmission \(DKG\): P056300 The on\-board power supply voltage is too high. Cause An overvoltage condition is detected exclusively within the transmission control unit, storing fault P056300 once the measured voltage exceeds 16V. Remedy This LI applies if the freeze frame data for P056300 show a supply voltage between 15.75 to 16.50 volts, and no other control units report overvoltage. \(figure 1\) Long Term Resolution: Software resolutions are being rolled out for various models. Check validity and ensure your Xentry is updated with latest Addons before continuing: 1. Perform software update for Y3/14 \- Transmission control for 8\-speed dual\-clutch transmission \(DKG\) \- available software listed in Parts 2. Clear fault memory and perform final test drive Short Term Resolution: Please clear faults and perform an extended test drive. The vehicle may be released to the customer until software is available. If the customer complaint matches this LI and the software currently installed on the vehicle is not listed, please submit a TIPS case to the Powertrain inbox with the following information: \- Initial Quick Test w/ Freeze Frame Data \- DKG Control Unit Log \- Latest EEPROM data \- Screenshot of software availability

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2026/MC-11035713-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2026/MC-11035713-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Transmission and driveline

## Trouble codes named

P0563

## Vehicles listed

- 2021 to 2022 MERCEDES\-BENZ A 220
- 2021 to 2022 MERCEDES\-BENZ A 220 4MATIC
- 2021 MERCEDES\-BENZ AMG A35
- 2021 to 2023 MERCEDES\-BENZ AMG CLA35
- 2021 to 2023 MERCEDES\-BENZ AMG CLA45
- 2021 to 2023 MERCEDES\-BENZ AMG GLA35
- 2021 to 2023 MERCEDES\-BENZ AMG GLA45
- 2021 to 2023 MERCEDES\-BENZ AMG GLB35
- 2021 to 2023 MERCEDES\-BENZ CLA 250
- 2021 to 2023 MERCEDES\-BENZ CLA 250 4MATIC
- 2021 to 2023 MERCEDES\-BENZ GLA 250
- 2021 to 2023 MERCEDES\-BENZ GLA 250 4MATIC
- 2021 to 2023 MERCEDES\-BENZ GLB 250
- 2021 to 2023 MERCEDES\-BENZ GLB 250 4MATIC

JSON: [/v1/bulletins/11035713](/v1/bulletins/11035713)

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