# Service bulletin LI88.50\-P\-080263

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: 11029960
- Published by NHTSA: 2026\-03\-11
- Manufacturer's number: LI88.50\-P\-080263
- Manufacturer's date: 2026\-03\-09
- NHTSA component: STRUCTURE:BODY; ELECTRICAL SYSTEM

## NHTSA's summary

Complaint The trunk lid does not open or close completely and must be operated manually by the customer. The following fault codes are stored in the Tailgate Control \(HKS\) control unit: P1CA000 \& B188C2A Cause If the trunk lid is repeatedly opened manually or the vehicle has experienced undervoltage, the trunk lid loses its normalization due to faulty software coding. Remedy For vehicles with a production date up to 01/22/26 \(232\) or 01/27/26 \(192\): Update the HKS N121/1 control unit and perform SCN coding. • If no new software is available, perform SCN coding. Vehicles with a production date 01/22/2026 \(232\) or 01/27/2026 \(192\) and later have already received the correct QNT from the factory.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2026/MC-11029960-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2026/MC-11029960-9999.pdf)

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

## Components

Body and frame, Electrical system

## Trouble codes named

B188C, P1CA0

## Vehicles listed

- 2025 to 2026 MERCEDES\-BENZ AMG GT43
- 2024 to 2025 MERCEDES\-BENZ AMG GT55
- 2024 to 2026 MERCEDES\-BENZ AMG GT55 4MATIC\+
- 2024 to 2026 MERCEDES\-BENZ AMG GT63
- 2025 to 2026 MERCEDES\-BENZ AMG GT63 4MATIC\+
- 2025 to 2026 MERCEDES\-BENZ AMG GT63 PRO 4MATIC\+
- 2025 MERCEDES\-BENZ AMG GT63 S E
- 2025 to 2026 MERCEDES\-BENZ AMG GT63 S E PERFORMANCE 4MATIC\+
- 2023 to 2026 MERCEDES\-BENZ AMG SL43
- 2022 to 2025 MERCEDES\-BENZ AMG SL55
- 2023 to 2026 MERCEDES\-BENZ AMG SL55 4MATIC\+
- 2022 to 2023 MERCEDES\-BENZ AMG SL63
- 2025 MERCEDES\-BENZ AMG SL63
- 2023 to 2026 MERCEDES\-BENZ AMG SL63 4MATIC\+
- 2024 to 2025 MERCEDES\-BENZ AMG SL63 S E
- 2024 to 2026 MERCEDES\-BENZ AMG SL63 S E PERFORMANCE 4MATIC\+
- 2026 MERCEDES\-MAYBACH SL 680 4MATIC\+

## Recalls for the same vehicles and component

- [26V281000](/recalls/nhtsa/26V281000.md), 2026-05-01: ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL
- [25V129000](/recalls/nhtsa/25V129000.md), 2025-02-28: ELECTRICAL SYSTEM:PROPULSION SYSTEM
- [2024615](/recalls/tc/2024615.md), 2024-10-18: Electrical
- [2024105](/recalls/tc/2024105.md), 2024-02-16: Electrical

## Other bulletins for the same vehicles and component

- [OTA\-Comm. Mod. SW. Update](/bulletins/11038222.md), 2026-10-06, Over\-the\-air update: ELECTRICAL SYSTEM. A software update will be performed that provides enhancements to the robustness and system stability of the communication module. The update is free of charge and runs in the background, which takes about 8 minutes to install. During this time, the vehicle can be driven without any restrictions, and the new software will be active with the next ignition cycle. Remedy MBUSA will conduct an OTA service campaign. Remote software updates are automatically downloaded and installed in the customer’s vehicle free of charge and do not require a dealer visit.
- [LI82.62\-P\-078631](/bulletins/11038217.md), 2026-10-06, Service bulletin: STRUCTURE:BODY. Complaint Clanking noise from the area of the speakers in the doors. Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even with the door trim removed, then continue the diagnosis working towards the speaker and if necessary, create a TIPS case with an informative video as an attachment. Note: Please refer to this document in the warranty claim and, once diagnosis is completed, select the damage code depending on the component part that is causing the issue. • If the noise stops when the door trim is removed, please proceed in accordance with LI72.10‑P‑067691. Information: In this case, do not use a damage code for the speakers in the warranty claim\!
- [LI54.71\-P\-079104](/bulletins/11037806.md), 2026-10-02, Service bulletin: ELECTRICAL SYSTEM. Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious cause usually with one of the following scenarios: • Flashing without a speed limit \("‑ ‑"\). • Flashing when current vehicle speed is under speed limit. • Flashing between US speed limit symbol and European speed limit symbol. NOTE: • Verify that the concern falls under one of the attachment videos. If not, then it is outside of the scope of this LI. • This also does not cover "Traffic Sign Inoperative" messages on the instrument cluster. Cause There are two identified reasons for this concern: 1. Country code information stored incorrectly at a particular geographic latitude range. 2. Incorrect reference data when the vehicle is started and a GPS signal is not immediately available. Remedy Update head unit software to latest version and the re‑check function in the same location. NOTE: Updated head unit software for AMG's has NOT been released yet. ETA 12/2026. If vehicle is still exhibiting one of the symptoms as described exactly as in the complaint section or as shown in the video attachments, open a TIPS case to the Body/Chassis/Entertainment inbox with the following: • Video of the concern. • Exact location \(latitude and longitude is best\)
- [LI54.21\-P\-080326](/bulletins/11037732.md), 2026-10-02, Service bulletin: ELECTRICAL SYSTEM. Complaint CEL light on with no drivability concerns. Cause Signal timing error. Remedy 167, 465: SW has been released. Update the FSAM to the latest SW version. 290, 118, 243, 247: Software is still in development. This fault code does not cause a drivability concern and will clear itself within 2‑ 3 key cycles. The vehicle can be released back to the customer.
- [LI54.71\-P\-079104](/bulletins/11036608.md), 2026-09-02, Service bulletin: ELECTRICAL SYSTEM. Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious cause usually with one of the following scenarios: • Flashing without a speed limit \("‑ ‑"\). • Flashing when current vehicle speed is under speed limit. • Flashing between US speed limit symbol and European speed limit symbol. NOTE: • Verify that the concern falls under one of the attachment videos. If not, then it is outside of the scope of this LI. • This also does not cover "Traffic Sign Inoperative" messages on the instrument cluster. Cause There are two identified reasons for this concern: 1. Country code information stored incorrectly at a particular geographic latitude range. 2. Incorrect reference data when the vehicle is started and a GPS signal is not immediately available. Remedy Update head unit software to latest version and the re‑check function in the same location. If vehicle is still exhibiting one of the symptoms as described exactly as in the complaint section or as shown in the video attachments, open a TIPS case to the Body/Chassis/Entertainment inbox with the following: • Video of the concern. • Exact location \(latitude and longitude is best\)
- [LI54.10\-P\-080880](/bulletins/11036192.md), 2026-08-14, Service bulletin: ELECTRICAL SYSTEM. Complaint Customer Complaint: \- AC charging is not possible. \- The departure time, charging pause, location\-based charging or target SOC limit is automatically set to 50% or to a random value in the Mercedes me application or in the charging settings on the head unit display. \(Picture 1 \& 3\) \- Incorrect notifications appear in the Mercedes me application for charging\-related functions. \(Picture 2\) Related DTCs in quick test: No related fault codes \(DTCs\) are stored in the relevant control units. CPC3 \- N127 \(Drivetrain control unit\) OBL223\_GEN4 \- N83/11 \(Alternating current charger for high\-voltage battery\) DCB223 \- N116/5 \- Direct current charge connection unit \(DCCU\) Picture1 The target SOC limit is automatically set to 50% or any random values during charging. Picture 2 Incorrect notification Example “Unable to unlock charging cable. Picture 3 Incorrect settings of charge interruption or pause. \(If applicable\) Cause \- The Customer shares their Mercedes me credentials \(password\) with a third\-party application, for example, a wall box application. This causes the Mercedes Benz backend server to receive random requests to reset the maximum SOC, departure time, charging pause, etc. \- Charging settings are set incorrectly, for example, incorrect departure time, charging program, charging interruption/ pause, etc. Remedy The remedies below may vary depending on the customer complaint. Refer to the remedy that best matches the customer complaint. Remedy 1: The target SOC limit is automatically set to 50% or to random values during charging. \- Change the Mercedes me login password on the Mercedes me homepage. \(My Account \> Login and Security \> Reset\). \(Refer to Annex 1\). Previously granted authorizations should then be revoked so that the charging settings can no longer be changed by external applications. Advise customers not to share the new password again. \- Are there any sub\-users? If yes, revoke their rights and reassess the function. \-If differences between the vehicle and the Mercedes me app are visible, a new synchronization is recommended. Turn off Digital Extras through the Mercedes me app or the MMCR portal, and then turn the services on again. Remedy 2: Incorrect notifications in the Mercedes me app for charging\-related functions. \- Restart synchronization between the app and backend. Turn off Digital Extras through the Mercedes me app or the MMCR portal, and then turn the services on again. \(Refer to Annex 2\) Remedy 3: Incorrect charge interruption or pause setting. \- Perform a factory reset of the head unit \(A26/17\). \(Home \> Functions \> System \> Reset\), or turn off/correct all charging settings. \(Refer to Annex 3\) Additional Information: \(Good to know\) The LED on the charging inlet or socket indicates whether charging is completed or paused. 1\) If the target SOC is reached, the charging inlet LED lights up Blue/Green without flashing. 2\) If charging is paused, the charging inlet LED lights up orange without flashing. Additionally, the head unit charging settings display a charging pause. Note: Do not replace any hardware components for these complaints. If the complaint cannot be solved, please contact via TIPS or CAC.
- [LI54.65\-P\-080132](/bulletins/11036142.md), 2026-08-12, Service bulletin: ELECTRICAL SYSTEM. Complaint 1. General Diagnostic Tips 2. One or More PARK Sensor Activations 3. Red Ring Around Vehicle 4. "Active Parking and Parking Assist Inoperative" on Instrument Cluster 5. Cameras 6. Other Park Topics. Cause Various root causes Remedy See attached diagnostic guide.
- [LI82.62\-P\-078631](/bulletins/11036101.md), 2026-08-11, Service bulletin: STRUCTURE:BODY. Complaint Clanking noise from the area of the speakers in the doors. Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even with the door trim removed, then continue the diagnosis working towards the speaker and if necessary, create a TIPS case with an informative video as an attachment. Information: Please refer to this document in the warranty claim and, after completing diagnosis, select the damage code corresponding to the component part that caused the problem. • If the noise stops when the door trim is removed, please proceed in accordance with LI72.10\-P\-067691. Information: In this case, do not use a damage code for the speakers in the warranty claim\!
- [LI82.60\-P\-080806](/bulletins/11036091.md), 2026-08-11, Service bulletin: ELECTRICAL SYSTEM. Complaint DAB, FM, or SDARS radio reception is limited, only a few stations are found. Cause The firmware installation was incomplete. Remedy In the A26/17 control unit "MBUX multimedia system" \(head unit\), use XENTRY to carry out the special process "All Modules"; this will reinstall the firmware completely.
- [LI82.60\-P\-080806](/bulletins/11035230.md), 2026-07-27, Service bulletin: ELECTRICAL SYSTEM. Complaint After an "Over the Air" update \(OTA\), FM or SDARS radio reception is limited; only a few stations are found. Cause The firmware installation was incomplete. Remedy In the A26/17 control unit "MBUX multimedia system" \(head unit\), use XENTRY to carry out the special process "All Modules"; this will reinstall the firmware completely.

JSON: [/v1/bulletins/11029960](/v1/bulletins/11029960)

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