2021 Mercedes-Benz A 220 4MATIC

My 2021 Mercedes-Benz A220 (M260 2.0L engine) triggered diagnostic fault code P052E, indicating a failure of the Positive Crankcase Ventilation (PCV) regulator valve / intake line assembly. Failure of this valve disrupts crankcase pressure, causing unmetered air intake, lean-running conditions, and engine hesitation/stalling risks. Mercedes-Benz issued a 15-year/150,000-mile extended warranty campaign for this exact PCV failure on M274 engines, but has excluded M260 engines despite identical failure modes. The manufacturer has not remedied this known design defect, creating potential drivability and engine pressure hazards.

NHTSA ID

11760025

Incident

Jun 1, 2025

Complaint Intermittent shift feel or thud/clunk noise perceived, such as a brief jerk or transmission reaction during certain driving situations. May be most noticeable when transitioning from a coasting condition to accelerator pedal application. May occur in all drive modes. Cause Dual‑clutch transmissions (DCT) inherently exhibit more dynamic shifting behavior compared to other types of transmissions. This is due to the use of physical clutches for starting and gear changes. In certain situations, dynamic driving behavior can lead to a slight jerk sensation which is a normal technical characteristic of the transmission. A typical example is a "Change of Mind" situation: • The customer is coasting towards a red traffic light. • The traffic light turns green while the vehicle is still coasting. • The customer then presses the accelerator pedal. In these situations, a slight jerk may occur briefly because the transmission must quickly engage the appropriate gear and control the clutches accordingly. Since shift forks are responsible for engaging the gears during shifting, a slight shifting noise may also be noticeable. Please note driving programs S, S+, and M are designed to provide sportier vehicle behavior and are not optimized primarily for maximum comfort, so this operation may be more audible. Remedy Verify the customer's concern and confirm proper transmission operation. If no faults or abnormal operating conditions are identified by IPR (Intelligent Predictive Repair), no hardware replacement is necessary. Inform the customer that the transmission has been designed to provide direct gear engagement and responsive vehicle performance. Under certain operating conditions, brief shift sensations may be perceptible and are consistent with the operating characteristics of the dual‑clutch transmission

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 have been released. 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 dualclutch transmission (DKG) available software listed in Parts 2. Clear fault memory and perform final test drive 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

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.

Dear Mercedes-Benz Owner: 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 regardless of ownership. Why the Warranty extension? On certain Model Year 2018 - 2024 A / C / CLA / CLS / E / G / GLA / GLB / GLC / GLE / GLS / GT / S / SL Mercedes-Benz vehicles, under certain circumstances, the DMTL may trigger erroneous Diagnostic Trouble Code ("DTC") entries that may result in the illumination of the Check Engine Malfunction Indicator Lamp ("MIL"). Any repairs under this warranty extension must be performed by an authorized Mercedes-Benz dealership. • If your preferred authorized Mercedes-Benz dealership performs a diagnosis and confirms that your vehicle has the issue, the repair will be covered under this extended warranty and performed at no cost to you. • This extended warranty does not apply to any other components or conditions beyond the ones mentioned above, and standard warranty terms apply, including the exclusions with respect to extra expenses, as identified in the Service and Warranty Information booklet.

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 (e.g., as described in LI82.85-P-076157) 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 Issues Head Unit Software/Hardware: • Outdated firmware, bugs, or hardware faults in the vehicle’s head unit can prevent a stable connection. iPhone Software/Hardware: • Similar issues in the iPhone, including buggy iOS updates or hardware problems, 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: • Faulty Cable: A damaged or poor-quality USB cable can cause intermittent or total loss of connection. • USB Port Issues: Dust, debris, or physical damage 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: • Incorrect or conflicting 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 FUP6 (E605.8) software has been released for the following chassis: 118, 177, 243,247,206,254,167,294,295,296,223, 297. Flash available software for the head unit and test for function. The LI will be updated once available for the remaining chassis. If the complaint remains after the SW update please continue with the steps below. 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. See attachment for further instructions.

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.