2021 Mercedes-Benz GLB 250 Technical Service Bulletins

225 technical service bulletins (TSBs) are on record for the 2021 Mercedes-Benz GLB 250. TSBs are notes manufacturers send to dealers about repair procedures for issues seen in the field. They are not recalls and do not by themselves mean a vehicle has a fault.

• 11028267Feb 2, 2026Engine. Complaint -Check engine light illuminated. -Engine runs rough. -Poor shifting or jerking when accelerating. -Fault codes stored related to mixture formation, injector quantity adjustment, or misfire. Note: One or more of the above symptoms can occur. It is possible that no fault codes are stored. Cause Leaking valve seat in cylinder head. Remedy -Perform cylinder leakage check as noted in WIS group 01.00. If…
• 11027904Jan 30, 2026Electrical system, Back-over prevention (rear camera). 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.
• 11027820Jan 26, 2026Electrical system. Complaint The vehicle's position on the map is displayed far away from its actual position, e.g. the vehicle is displayed as being in the middle of the ocean. Note: No relevant DTC is displayed during the quick test. Cause The GNSS antenna is not correctly inserted at the GNSS connection (see picture in the attachment) in the head unit (A26/17). Remedy Insert the plug into the GNSS connection and ensure that the…
• 11027782Jan 21, 2026Other or unknown. Complaint The intent of this document is to provide workshops with helpful technical reference language. • Commonly used acronyms in LI's and TIPS cases. • Control unit names, numbers, and how to identify. • Network/wiring architecture groups to baumuster quick reference. • Platform to baumuster quick reference.
• 11027751Jan 16, 2026Visibility (wipers, defrost, mirrors). Complaint Customer states the AC either does not cool/has poor performance or heat is insufficient. Cause Many possible root causes Remedy *Note - This Li does not apply if there are other Li's that apply to your concern OR you have a fault and/or guided test that leads to a root cause. AC Diagnosis (General) Initial Steps Verify Customer Concern • Confirm the issue reported by the customer. Compare to Like Vehicle…
• 11027682Jan 15, 2026Visibility (wipers, defrost, mirrors). Complaint Customer states the AC either does not cool/has poor performance or heat is insufficient. Cause Many possible root causes Remedy AC Diagnosis (General) Initial Steps Verify Customer Concern • Confirm the issue reported by the customer. Compare to Like Vehicle • Determine if the behavior is normal by comparing with a similar vehicle. Determine Your Game and Players • Identify the diagnostic strategy and…
• 11027583Jan 10, 2026Electrical system. Complaint After the charging process is complete, an instrument cluster message with a charging error appears and FC P0CFE00 is stored in control unit "N83 - AC charger for high-voltage battery (SG-LG)". The instrument cluster message and the FC memory entry can also appear at the beginning of the charging pause during delayed charging. Both only occur in combination with active pre-entry climate control. Cause…
• 11027566Jan 7, 2026Visibility (wipers, defrost, mirrors). Complaint Customer states the AC either does not cool/has poor performance or heat is insufficient. Cause Many possible root causes Remedy AC Diagnosis (General) Initial Steps Verify Customer Concern • Confirm the issue reported by the customer. Compare to Like Vehicle • Determine if the behavior is normal by comparing with a similar vehicle. Determine Your Game and Players • Identify the diagnostic strategy and…
• 11026832Dec 19, 2025Transmission and drivetrain. Complaint Oil residue in connector of transmission control unit in dual-clutch transmission models 724.0 and 724.1. Cause As part of the production process, the electrohydraulic controller units are subjected to a function test in an oil bath. Any oil residue remaining in the connector area can be regarded as production process-related.
• 11026835Dec 18, 2025Electrical system. Complaint The flap of the reversing camera opens and closes by itself during forward travel several times during the trip. No camera image is displayed in the head unit. The reversing camera or the 360° system functions normally when activated manually or by engaging drive range "R". Cause This is not a malfunction, but an intended system behavior. Calibration of the reversing camera is in progress.
• 11026611Dec 11, 2025Electrical 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.
• 11026127Dec 3, 2025Electrical system. Complaint Displayed Message: “Driver camera not functioning, see Operator’s Manual” Cause Interior temperature too high due to: • Summer heat • Direct sunlight • Lack of air conditioning or ventilation Camera enters self-protection mode to prevent overheating. Remedy Do NOT replace any parts. The driver camera (NTG7: MDC295; CIVIC.i2: CIVIC206) is operating as designed. Allow the interior to cool down.
• 11026020Dec 3, 2025Electrical system. 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.
• 11025648Nov 15, 2025Transmission and drivetrain. Complaint Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The clunk is heard once when changing from forward to reverse (and vice versa). Note: Sound file in attachment Cause If the complaint is eliminated by experimentally loosening the outboard collar nut (by 1 turn), the problem is due to micromovement in the connection between the wheel bearing inner…
• 11025544Nov 6, 2025Electrical system. Complaint USB port not functioning properly. Cause Most reported USB port issues are due to improper use or contamination. Note: Any repair costs must be discussed with the customer beforehand. Common external factors identified include: • Fluid intrusion • Broken bushings or physical damage See attachments. Remedy If a component needs replacement without visible external damage, submit a detailed TIPS case.
• 11024810Oct 31, 2025Electrical system. Issue Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the 48-V on-board electrical system battery software might not meet current production specifications. A communication error may occur when reactivating the 48V lithium-ion battery during reinitialization. The system might detect and store this error, causing the malfunction indicator lamp to…
• 11024632Oct 29, 2025Transmission and drivetrain. Complaint Instrument cluster message "4MATIC inoperative". The following fault code may be present in all-wheel drive control unit N15/17: P147354 - Erroneous adaptation of the transfer case. The calibration is missing. P14759A - The coupling of the transfer case has malfunctioned. The operating conditions for the component or the system have not been fulfilled. Cause Coupling of the rear axle differential has…
• 11024405Oct 20, 2025Brakes. Complaint At low speeds and light brake pressure, brakes will make a groaning or honking noise. Cause Frictional vibrations with very light brake pressure/modulations. Remedy This condition can be duplicated on most vehicles. To validate, use a like for like reference vehicle. The noise is normal behavior under the conditions listed. With very light brake pressure this noise can be induced/caused due to normal…
• 11024276Oct 10, 2025Seats. Complaint The "Easy entry and exit feature" function deactivates itself after a brief period. (see attachment). Cause The cause is currently being investigated. Remedy Update the HU7 to the latest software version, then perform a factory reset of the HU7. Steps to perform factory reset: Navigate to Settings > System > Reset > Reset to factory settings and confirm.
• 11024274Oct 10, 2025Electrical system. 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.
• 11023347Sep 25, 2025Electrical system. Complaint The result from the XENTRY battery test does not match the current state of the battery. Cause The XENTRY battery tester uses the stored on-board electrical system data in the SAM module to access the health of the 12 volt battery. The XENTRY battery test may not take into account a single discharge event because the SAM or EZS cannot record the data if the battery is discharged. Note: A discharged…
• 11023193Sep 17, 2025Transmission and drivetrain. Complaint Transmission control unit Y3/8n4 (fully integrated transmission control unit (VGS)) not listed in quick test and/or no communication possible with VGS. Cause Transmission control unit Y3/8n4 Remedy For vehicles with 722.9 transmission: Ensure LI54.15-P-057373 is performed before replacing any component parts. After processing and complying with the above document(s): 1. Perform an ignition reset on Y3/8n4…
• 11023155Sep 16, 2025Body and structure. Complaint Bulging and contact of the rear spoiler when hatch is opened (picture 1-1). When opening the rear hatch, the rear spoiler rests at the roof edge, which can result in damage to the rear spoiler and roof if the hatch is forcefully opened when the rear spoiler is bulged over (picture 1-2). Cause In the event of higher outside temperatures, the spoiler of the rear-end door thermally expands and may be above…
• 11023026Sep 4, 2025Electrical system. Complaint No audio is output either in radio mode, or with media playback via app, Bluetooth or USB. In such cases, "Playback not active" is shown in the display. Cause Mute line between communication module N112/2 and sound control unit N40/3. Remedy Check the mute cable between control units N112/2 (communication module) and N40/3 (sound system). • Inspect the cable and plug contacts for damage or deformation. •…
• 11023048Sep 3, 2025Electrical system. Complaint Customer complains about anti-theft alarm system triggering without obvious cause when the vehicle is parked and/or when entering the vehicle. All MFA2 and 167 derivates with code 882 may be affected. Cause This is caused by a sporadic loss of communication to the anti-theft alarm system [N26/6].
• 11023025Sep 3, 2025Visibility (wipers, defrost, mirrors). Complaint To prevent the wiper motor from overheating, the wipe frequency is reduced automatically when a dry windshield is detected. In specific situations under various independent ambient conditions, this detection could be activated by mistake, with the result that the wiper system switches from activated continuous operation to intermittent operation when it's raining. Cause Sensitive parameters for detecting…
• 11022909Sep 3, 2025Other or unknown. Complaint The Dynamic or Park Camera button in the LCP is stuck or does not react. Cause In rare cases, tension between the component parts of the LCP and trim of the center console could result in the buttons sticking. Remedy Remove LCP and reinstall while ensuring it is free of any tension. Replacement is not necessary.
• 11022048Aug 7, 2025Transmission and drivetrain. Complaint Transmission limp-home mode with fault message in IC "Gear Change to R Not Possible", the even gears are locked. The concern of transmission limp-home mode disappears after the ignition is switched off and on again. P092500 The shift valve of the hollow shaft has a malfunction. _ is present in the DKG Control Unit (Y3/14n4), and the extended freeze frame data shows hex code 25 F2 (see attachments for…
• 11022045Aug 5, 2025Transmission and drivetrain. Complaint Customer complaints regarding automatic transmission 724.1 (8FDCT & 8FDCT hybrid) For faster, more effective and more targeted diagnosis, Intelligent Predictive Repair (IPR) has been developed and integrated into XENTRY Diagnosis. This ensures an automated diagnosis process.
• 11021897Aug 4, 2025Engine. Complaint: Check engine light comes on when driving/starting the vehicle. No drivability concerns. Cause: Communication error in G1/3 - 48 V on-board electrical system battery (48 V LIB) or N127 - 'Drivetrain' control unit (PTCU)saved and/or current Remedy: Update the software for the control unit G1/3 - 48 V on-board electrical system battery (48 V LIB) : --> Remedy-SW A001902042425/12 If the fault profile still…
• 11022052Aug 1, 2025Electrical system. 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.
• 11021149Aug 1, 2025Electrical system. Complaint Check engine light comes on when driving/starting the vehicle. No drivability concerns. Cause SW conflict of the 48V battery Remedy Update the 48V battery to SW 25/12 A0019020424
• 11021148Aug 1, 2025Electrical system. 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 Update the 48V battery to SW 25/12 A0019020424
• 11021153Jul 31, 2025Seats. Complaint The "Easy entry and exit feature" function deactivates itself after a brief period. (see attachment). Cause The cause is currently being investigated. Remedy 1. Update the A26/17 MBUX multimedia system (head unit) to the latest software version FUP5 Opt. (E505.4) or newer. 2. Perform a factory reset of the head unit after the update. If the issue continues: • Capture a head unit log and a Body CAN trace…
• 11021150Jul 29, 2025Electrical system. Complaint After a software update for instrument cluster (IC) control unit (N133/1) is performed the following customer complaints may be noted: - One or more menu selections (navigation, AMG, etc.) are missing from the instrument cluster display - The menu icons are present but the functionality does not appear in instrument cluster display after it is selected Cause - Communication between the instrument cluster…
• 11020675Jul 11, 2025Electrical system. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the MBUX system software does not correspond with the latest series production configuration. The MBUX system will receive an OTA update that includes general product improvements and robustness enhancements for the “Live Traffic Information” and “Point of Interest” (POI) features. MBUSA will conduct an…
• 11019750Jun 24, 2025Electrical system. Complaint The head unit cannot be operated via the steering wheel buttons on the right side. Cause A26/17 - MBUX multimedia system (head unit) software Remedy Update the A26/17 - MBUX multimedia system (head unit) to newest/latest software. Then recommission steering wheel electronics N135 - steering wheel electronics (LRE). If the problem is still present, please create a TIPS case. Note: Please do not replace any…
• 11019016May 30, 2025Fuel system, Electrical system. In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the warranty coverage for the Diagnostic Module for Tank Leakage detection (“DMTL”) on your vehicle from the original New Vehicle Limited Warranty of 4 years / 50,000 miles to 15 years/150,000 miles (whichever occurs first). This applies to the vehicle…
• 11018622May 27, 2025Electrical system. 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 Perform guided test for fault code "P0A7F00". Important! To ensure a bus idle of 90 minutes is achieved, the vehicle should be locked and the key placed a minimum of 30 feet from the vehicle) See SI82.85-P-0046A
• 11019018May 21, 2025Transmission and drivetrain. Complaint Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The clunk is heard once when changing from forward to reverse (and vice versa). Note: Sound file in attachment Cause If the complaint is eliminated by experimentally loosening the outboard collar nut (by 1 turn), the problem is due to micromovement in the connection between the wheel bearing inner…
• 11018625May 15, 2025Fuel system. In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA, LLC (“MBUSA”) is extending the warranty coverage on the Diagnostic Module for Tank Leakage detection (DMTL) in certain Model Year (“MY”) vehicles listed below from the original New Vehicle Limited Warranty of 4 years/50,000 miles to 10 years/120,000 miles…
• 11018164May 7, 2025Electrical system. Complaint Please note that the exact quick test conditions must be met as seen below. If not exactly as listed below, there is no need to create a TIPS case referencing this LI unless further assistance is needed outside of this document.
• 11018031May 5, 2025Electrical system. Complaint Individual functions such as sliding sunroof or roller sunblind can no longer be operated using the gesture recognition system. Cause Gesture recognition system control unit software N168 Remedy For vehicles before modification year 23/2: Perform SCN coding in control unit OMSH223 (N168). For vehicles as of modification year 23/2: Considered to be a series production configuration. A change will not be…
• 11018215May 2, 2025Electrical system, Engine. Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the SCN coding in the Belt-driven Starter Alternator (BSA) control unit does not correspond to the latest production specifications. MBUSA will conduct a service campaign. An authorized Mercedes-Benz dealer will perform an SCN coding in the BSA control unit.
• 11018206May 2, 2025Electrical system. Complaint The result from the XENTRY battery test does not match the current state of the battery. Cause The XENTRY battery tester uses the stored on-board electrical system data in the SAM module to access the health of the 12 volt battery. The XENTRY battery test may not take into account a single discharge event because the SAM or EZS cannot record the data if the battery is discharged. Note: A discharged…
• 11017500Apr 28, 2025Exterior lighting. Complaint Headlamps leaking or fogged Cause The fogging of the headlamp is a natural phenomenon which can occur under certain climatic conditions. In contrast to a leaky headlamp, physical fogging does not result in a technical impairment of the headlamp. A leak test must be performed to determine if physical fogging exists or if the headlamp is leaky. Remedy Check for external damage: You can identify a damaged…
• 11017496Apr 28, 2025Exterior lighting. Complaint Headlamp, front fog lamp leaky or fogged Cause Fogging of the headlamps is a natural phenomenon, which can occur under certain climatic conditions. It does not lead to any technical impairment of the headlamp. Remedy NOTE: If a pressure compensation diaphragm is fitted in the housing cover, then the lamp unit is a "closed system". Headlamp: Remedy 1 Clearing fogged/condensed LED headlamps and LED rear…
• 11017226Apr 24, 2025Electrical system. 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 Perform guided test for fault code "P0A7F00". Important! To ensure a bus idle of 90 minutes is achieved, the vehicle should be locked and the key placed a minimum of 30 feet from the vehicle)
• 11017210Apr 22, 2025Electrical system. Complaint The message "Device detected at diagnostics connection See Operator’s Manual" appears sporadically in the multifunction display of the instrument cluster while driving (see picture in attachment).
• 11017217Apr 21, 2025Visibility (wipers, defrost, mirrors). Complaint Random heating of air conditioning system. Cause Temperature sensor in overhead control panel (OCP) delivering incorrect values: The temperature sensor in the overhead control panel is malfunctioning. Fault code B110709 or fault code B11F697 are present in the overhead control panel with the status (active) or (active stored).

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