# Service bulletin LI54.10\-P\-078888

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: 11026020
- Published by NHTSA: 2025\-12\-03
- Manufacturer's number: LI54.10\-P\-078888
- Manufacturer's date: 2025\-12\-03
- NHTSA component: ELECTRICAL SYSTEM

## NHTSA's summary

Complaint The check engine light illuminates or the 48 V message is displayed in the instrument cluster Cause Fault code "P0A7F00" stored in the 48 V battery G1/3 and/or is current. Remedy 1. Perform software update: In the given problem case, update the software for the control unit G1/3 \- 48 V on\-board electrical system battery \(48V LIB\) : \-\-\> Remedy SW A0019020424 25/12 2. Carry out SOH reset routine: \- Switch on ignition \- Read actual value 209 in XENTRY Diagnostics at G1/3 \(48 V battery\) "State of Health Capacity\-SOHC" Valid for OBD markets \-\- If the value is \> 80%, no restoration process required \-\- If the value is \< 81%, continue with the following steps Valid for non\-OBD markets \-\- If the value is \> 75%, no restoration process required \-\- If the value is \< 76%, continue with the following steps Perform capacity restoration procedure: \- Discharge 48 V battery in vehicle with ignition "On" and check SOC of 48 V battery in the instrument cluster's workshop menu \- For SOC \< 25%: Stop unloading and lock the vehicle with the key out of range; \(bus idle\) \- After 1.5 h of bus idle: Charging the 48V battery \- When SOC reaches or exceeds 65%, stop charging and lock the vehicle with the key out of range; \(bus idle\) \- After 1.5 h of bus idle: Switch on ignition Read actual value 209 in XENTRY Diagnostics at G1/3 \(48 V battery\) "State of Health Capacity\-SOHC" Valid for OBD markets \- SOH \> 82%: Process is complete and clear fault memory \- SOH \< 83%: Repeat the steps once more. If the value is still too low after 5 repetitions: Cancel healing process and provide feedback in TIPS case.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11026020-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11026020-9999.pdf)

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

## Components

Electrical system

## Trouble codes named

P0A7F

## Vehicles listed

- 2020 to 2024 MERCEDES\-BENZ AMG CLA35
- 2026 MERCEDES\-BENZ AMG CLA35 4MATIC
- 2014 to 2024 MERCEDES\-BENZ AMG CLA45
- 2026 MERCEDES\-BENZ AMG CLA45S 4MATIC\+
- 2024 to 2025 MERCEDES\-BENZ AMG GLA 35
- 2024 MERCEDES\-BENZ AMG GLA 35 4MATIC
- 2026 MERCEDES\-BENZ AMG GLA 35 4MATIC
- 2021 to 2023 MERCEDES\-BENZ AMG GLA35
- 2021 to 2023 MERCEDES\-BENZ AMG GLA45
- 2021 to 2025 MERCEDES\-BENZ AMG GLB35
- 2026 MERCEDES\-BENZ AMG GLB35 4MATIC
- 2018 to 2026 MERCEDES\-BENZ CLA 250
- 2026 MERCEDES\-BENZ CLA 250 4MATIC
- 2014 to 2017 MERCEDES\-BENZ CLA250
- 2021 to 2026 MERCEDES\-BENZ GLA 250
- 2024 MERCEDES\-BENZ GLA 250 4MATIC
- 2026 MERCEDES\-BENZ GLA 250 4MATIC
- 2020 to 2026 MERCEDES\-BENZ GLB 250
- 2026 MERCEDES\-BENZ GLB 250 4MATIC

JSON: [/v1/bulletins/11026020](/v1/bulletins/11026020)

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