# Service bulletin LI82.85\-P\-079530

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: 11026607
- Published by NHTSA: 2025\-12\-15
- Manufacturer's number: LI82.85\-P\-079530
- Manufacturer's date: 2025\-12\-12
- NHTSA component: ELECTRICAL SYSTEM

## NHTSA's summary

Complaint The following most common complaints may be observed: • Brief connectivity interruptions when using Apple CarPlay over Wi\-Fi • Audio cuts out • Device not recognized • No operation possible Cause There are multiple possible causes for an iPhone disconnecting from a vehicle’s head unit while using Apple CarPlay. These include hardware, software, and environmental factors: Environmental Interference: External Sources: • Passing under toll bridges, driving near airports, or areas with heavy electronic interference can cause connection drops. Cellular Networks: • Interference from nearby cell towers operating on similar frequencies \(usually 2.4GHz or 5GHz\) can disrupt the signal. Storage Location: • Keeping your phone in a handbag or surrounded by other objects inside the vehicle can create physical or electronic interference. Device and Software Topics: Head Unit Software/Hardware: • Hardware causes or outdated firmware in the vehicle’s head unit can prevent a stable connection. iPhone Software/Hardware: • Similar causes in the iPhone, including outdated iOS versions or hardware causes, may affect performance. Reset or Reboot: • Automatic rebooting or resetting of either the head unit or the iPhone will temporarily disrupt CarPlay. Connection and Settings: Wired Connections • Cables: A compromised or poor\-quality iPhone\-USB cable can cause intermittent or total loss of connection. • USB Ports: Dust, debris, or physical deformation in the USB port of either the head unit or the iPhone can also lead to disconnects. Wireless Connections: • Intermittent Bluetooth/Wi\-Fi: Unstable wireless communication \(Bluetooth/Wi\-Fi\) can frequently break the Car\- Play connection. Power Management: • Battery Saver Mode: Enabling low power mode may restrict background processes, affecting CarPlay. • Vehicle’s Electrical System: Unstable power delivery from the car’s battery or electrical interruptions can cause the head unit to malfunction. Phone \& App Configuration: Phone Settings: • Settings \(especially Bluetooth or Wi\-Fi\) on your iPhone can interfere with the CarPlay link. Third\-Party Apps/Profiles: • Installed apps or configuration profiles may conflict with CarPlay’s operation. • Native apps are apple maps, apple music, audio books, apple news, podcasts, messages and phone. All other apps are considered third party apps. App Conflicts: • Running conflicting apps that require similar system resources as CarPlay can cause instability. Mobile Data Plan: • Streaming from online sources without sufficient mobile data can result in lost connectivity. Other Factors: Heat \& Overheating: • If either the phone or the head unit overheats, they may disable certain functions to prevent damage, leading to disconnection. User Actions: • Accidentally disconnecting the device in settings, or physically moving or bumping the phone or cable, may disrupt the connection. Remedy Guided Diagnostic Path for Apple CarPlay Connection Issues Please follow the steps below to systematically diagnose and resolve CarPlay concerns: Update Devices: • Ensure the iPhone is updated to the latest available iOS version. • Ensure the vehicle’s head unit is updated to the latest software version available. Isolate the Issue: • Check whether the symptom persists with another iPhone running the latest iOS version. • Test both wireless and wired CarPlay connections: • Does the issue only occur with wireless CarPlay? • Does the wired connection to the phone function correctly? Further Troubleshooting Steps: • Reboot the iPhone. • Reboot the head unit via the settings menu \(user data reset\). • Remove saved CarPlay connections • Delete the head unit information from the iPhone \(see attached video for guidance\). • Delete the iPhone from the head unit’s list of paired devices. • Remove the head unit entry from CarPlay settings on the iPhone. • Re\-initiate pairing between the head unit and the iPhone to establish a new connection certificate. See attachment for complete text.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11026607-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11026607-9999.pdf)

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

## Components

Electrical system

## Vehicles listed

- 2023 to 2024 MERCEDES\-BENZ AMG C43
- 2023 to 2025 MERCEDES\-BENZ AMG C43 4MATIC
- 2023 to 2024 MERCEDES\-BENZ AMG C63 S E
- 2024 to 2025 MERCEDES\-BENZ AMG C63 S E 4MATIC\+
- 2024 MERCEDES\-BENZ AMG CLE53
- 2024 to 2025 MERCEDES\-BENZ AMG CLE53 4MATIC\+
- 2025 MERCEDES\-BENZ AMG CLE53 4MATIC\+ CABRIOLET
- 2025 MERCEDES\-BENZ AMG E 53 4MATIC\+ WAGON
- 2024 MERCEDES\-BENZ AMG GLC43
- 2024 to 2025 MERCEDES\-BENZ AMG GLC43 4MATIC
- 2024 to 2025 MERCEDES\-BENZ AMG GLC43 4MATIC COUPE
- 2024 to 2025 MERCEDES\-BENZ AMG GLC63 S E
- 2025 MERCEDES\-BENZ AMG GLC63 S E 4MATIC\+
- 2025 MERCEDES\-BENZ AMG GLC63 S E 4MATIC\+ COUPE
- 2022 to 2025 MERCEDES\-BENZ C 300
- 2021 to 2025 MERCEDES\-BENZ C 300 4MATIC
- 2024 MERCEDES\-BENZ CLE 300
- 2024 to 2025 MERCEDES\-BENZ CLE 300 4MATIC
- 2024 to 2025 MERCEDES\-BENZ CLE 300 4MATIC CABRIOLET
- 2024 MERCEDES\-BENZ CLE 450
- 2024 to 2025 MERCEDES\-BENZ CLE 450 4MATIC
- 2024 to 2025 MERCEDES\-BENZ CLE 450 4MATIC CABRIOLET
- 2024 to 2025 MERCEDES\-BENZ E 350
- 2025 MERCEDES\-BENZ E 350 4MATIC
- 2024 MERCEDES\-BENZ E 450
- 2025 MERCEDES\-BENZ E 450 4MATIC
- 2024 to 2025 MERCEDES\-BENZ E 450 4MATIC ALL\-TERRAIN
- 2023 to 2026 MERCEDES\-BENZ GLC 300
- 2023 to 2026 MERCEDES\-BENZ GLC 300 4MATIC
- 2024 to 2026 MERCEDES\-BENZ GLC 300 4MATIC COUPE
- 2024 MERCEDES\-BENZ GLC 300 COUPE
- 2025 MERCEDES\-BENZ GLC 300E
- 2025 MERCEDES\-BENZ GLC 350 E 4MATIC

## Recalls for the same vehicles and component

- [26V281000](/recalls/nhtsa/26V281000.md), 2026-05-01: ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL
- [2025213](/recalls/tc/2025213.md), 2025-04-17: Electrical
- [24V115000](/recalls/nhtsa/24V115000.md), 2024-02-16: ELECTRICAL SYSTEM:WIRING:FUSES AND CIRCUIT BREAKERS

## Other bulletins for the same vehicles and component

- [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 \(latitude and longitude is best\)
- [LI82.60\-P\-079747](/bulletins/11037489.md), 2026-09-26, Service bulletin: ELECTRICAL SYSTEM. Complaint The Apple Music app is no longer available in the head unit apps menu after updating the software of the \(A26/17 ‑ MBUX multimedia system \+ instrument cluster \(head unit\)\) to E333.8 / A236 904 19 00. Cause Head unit software \(CIVIC206\) Remedy NOTE: Do not replace any component parts The new Apple Music app version is now available. The app should automatically be downloaded and available. If the app is not shown available, check via the Mercedes‑Benz App Store directly in the vehicle and download the app. NOTE: Please refer to this LI in the warranty claim in the "Notes" section\!
- [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 \(latitude and longitude is best\)
- [LI72.20\-P\-075746](/bulletins/11036511.md), 2026-08-31, Service bulletin: ELECTRICAL SYSTEM; STRUCTURE:BODY. Complaint Tailgate opens unintentionally. Cause Accidental or unnoticed activation of the button to open the tailgate on the vehicle key. EXAMPLE: when stored in trouser pocket, handbag etc. Remedy As of the 6th generation, the vehicle key can be recoded so that the tailgate no longer opens as a result of a long press on the button, but by double‑clicking on the button instead. This reduces the likelihood of the button being activated accidentally or unintentionally. The recoding can be carried out as follows: 1. Add SA Code O19 into VeDoc \(O for Oscar, not "zero"\) • an XSS ticket may be necessary to add the SA code 2. Perform SCN coding of EIS N73 control unit 3. Deactivate the vehicle key \(a successful deactivation is indicated by the LED lighting up 2x briefly and then 1x for a long period\). 4. Place the vehicle key in the storage compartment on the key symbol and turn on the ignition. IMPORTANT: all other vehicle keys must be outside the recognition range of the vehicle when doing this\! Perform steps 3 and 4 successively for all vehicle keys. Notes: 6th, 7th and 8th generation keys can be deactivated as follows: Up to modification year 22/1 by double clicking the "Lock button" As of modification year 22/1, by press and holding the “Lock button", then double‑click the “Unlock button" at the same time. On model series 167, the storage compartment with the key symbol is located in the armrest. The SCN coding from the EZS is only transferred correctly to the vehicle key under the following conditions: Only one vehicle key is located in the vehicle, this key has been deactivated and it is positioned on the marking in the storage compartment for the data transfer. The costs for this adaptation are to be borne by the customer. For the newer BR 174, 178, 244, 248, 520, and 540, a software update must be initiated, as there is no way to perform SCN coding.
- [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.
- [LI82.60\-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.
- [LI80.35\-P\-080195](/bulletins/11035487.md), 2026-08-03, Service bulletin: ELECTRICAL SYSTEM. Complaint "Key Not Detected" message appears on the IC while driving even though the key is in the car and no doors have been opened. Cause EZS SW Remedy Confirm that the message is not due to the driver's door being opened and that the door latch is reading properly. For vehicles that do not have the above issues, EZS SW is released for option code 805 ONLY. For all other vehicles, the SW is still in development. Current workaround is to ensure that the key is left on the antenna in the storage compartment.
- [OTA\-MBUX Software Update](/bulletins/11035237.md), 2026-07-27, Over\-the\-air update: ELECTRICAL SYSTEM. Mercedes\-Benz AG, the manufacturer of Mercedes\-Benz vehicles, has determined that on certain subject vehicles, there is a new software update for the MBUX Infotainment System. An OTA update will further enhance functionality and stability of the MBUX Infotainment System. This OTA update will include New DIGITAL LIGHT projections for opening/closing the vehicle doors, Apple iPhone notifications synchronization, and removal of online Metadata Enrichment \(e.g. album cover pictures, composer information, and pictures of the artist\). 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.
- [LI82.60\-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.
- [LI80.35\-P\-080195](/bulletins/11035220.md), 2026-07-24, Service bulletin: ELECTRICAL SYSTEM. Complaint "Key Not Detected" message appears on the IC while driving even though the key is in the car and no doors have been opened. Cause Possible SW Remedy Confirm that the message is not due to the driver's door being opened and that the door latch is reading properly. For vehicles that do not have the above issues, SW is released for option code 805 ONLY. For all other vehicles, the SW is still in development. Current workaround is to ensure that the key is left on the antenna in the storage compartment.

JSON: [/v1/bulletins/11026607](/v1/bulletins/11026607)

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