2022 Mercedes-Benz C 300 4MATIC

Complaint Diverse functional limitations in the vehicle in combination with various warning and fault messages in the instrument cluster display. Cause Communication timeouts mean that communication errors may occur in the on‑board electrical system, which can result in various fault messages being displayed in the instrument cluster. This could be down to delayed feedback from the drivetrain control unit (N127) (CPC) to other control units networked to the CAN bus. Information: Only valid for vehicles through production period 10/2025. Not valid for vehicles with control unit CDCC (N125, central controller charging and driving) • It may not be possible to attribute any communication errors stored in the control units on the CAN bus to a specific cause • In rare instances, there may be a brief activation of the yellow warning lamp for engine diagnosis or there may be a sporadic delay with the start enable. • There may not be any specific fault codes present that indicate a specific component. Example image: Fault messages in instrument cluster: The reason for this could be down to delayed feedback from the control unit CPC3 to other control units networked on the CAN bus. Remedy Do not replace any components!!! ******************************************************************************************************* 1. Connect charger (see AR54.10‑P‑1127WT). Note: An adequate voltage from the on‑board electrical system battery must be guaranteed for the entire duration of the work procedure. Otherwise, the control units could be damaged if an undervoltage occurs. Information: Observe the operating instructions of the charger. Information: Use the charger to ensure an adequate voltage (at least 12.5 V) from the on‑board electrical system battery. ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 2. Connect diagnostic system (see AD00.00‑P‑2000‑06FR). Note: Always use the latest XENTRY Diagnostics software release. Information: Strict compliance with the operation steps in XENTRY Diagnostics is absolutely essential. ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 3. Select control unit N127 (CPC) via the direct link using XENTRY Diagnosis. Information: To do so, select the following menu items: Control units view → Drive systems → N127 ‑ "Drivetrain" control unit (CPC) ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 4. Update software for control unit N127 (CPC) (see AR54.21‑P‑0014‑01Y). Info: To do so, select the following menu items: Adaptations → Control unit update → Update control unit software. Information: You are then automatically guided through the steps "Update of control unit software" and "SCN coding". Always observe the following operation steps at all times ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 5. Disconnect diagnostic device from vehicle (see AD00.00‑P‑2000‑06FR). ‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑‑ 6. Disconnect charger from vehicle (see AR54.10‑P‑1127WT).

Complaint Wheezing noises/squeaking noises from the front shock absorbers when passing over surface undulations and rough road. Noise MUST match those heard in the attached videos. Cause • Wheezing noises: Flow noises of the damper oil • Squeaking noises: From the mechanical rubber valve in the dividing piston Remedy In case of complaints, the front shock absorbers must be replaced. If shocks have been replaced and noise persists, please open a TIPS case to the Body, Chassis, Entertainment inbox.

Complaint Wheezing noises/squeaking noises from the front shock absorbers when passing over surface undulations and rough road. Noise MUST match those heard in the attached videos. Cause • Wheezing noises: Flow noises of the damper oil • Squeaking noises: From the mechanical rubber valve in the dividing piston Remedy In case of complaints, the front shock absorbers must be replaced. If shocks have been replaced and noise persists, please open a TIPS case to the Body, Chassis, Entertainment inbox.

Complaint Oil seeping from turbocharger oil return line at connection to engine block. Low oil level warning. Oil observed under vehicle. Cause Return line under tension due to turbo rotation. Remedy Inspect turbocharger housing for rotation (refer to attachment). If rotation is confirmed, the turbocharger and oil return line must be replaced.‑Resealing or replacing only the oil return line is not sufficient and will not resolve the symptom.‑Clean noise insulation on right side of engine if necessary. Replace insulation if cleaning is not sufficient.‑Observe foot notes regarding additional parts in XENTRY parts information when ordering turbocharger.

Complaint Customer complaints relating to automatic transmission 725.0 (NAG3 Classic /9G‑TRONIC automatic transmission) and 725.1 (NAG3 facelift/9G‑TRONIC automatic transmission facelift) 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. Cause As part of the on‑going quality monitoring process and associated quality and damaged part appraisals, a high number of ineffective repairs have been discovered. Such ineffective repairs have a negative impact on all those involved. For the customer, it means high costs and long repair times and for the dealer, it may result in the warranty claim being rejected. Remedy General note: IPR is available for: ‑ NAG3 Classic (automatic transmission 725.0) ‑ NAG3 Classic ‑ AMG sport model (AMG 43 and AMG 53 with converter, automatic transmission 725.0) ‑ NAG3 Classic ‑ Hybrid (automatic transmission 725.0) ‑ NAG3 Classic ‑ AMG 63 (automatic transmission 725.0) ‑ NAG3 MOPF ISG2 (automatic transmission 725.1) ‑ NAG3 MOPF Hybrid (automatic transmission 725.1) ‑ NAG3 MOPF AMG sport model (AMG 53/AMG 53e with ISG48V2 & converter /hybrid, automatic transmission 725.1) ‑ NAG3 MOPF AMG 43/63 with engine 139/177 (automatic transmission 725.1) Steps for the Service Advisor: Important: The more information and detail that can be given to the workshop about the complaint, then the more effective the subsequent diagnosis with IPR can be. To this end, a detailed service reception questionnaire has been provided to help the Service Advisor ask the right questions about the complaint. ‑ Ask precise details about the customer complaint and the conditions and context. ‑ Fill out the service reception questionnaire (please see WIS document: OF27.00‑P‑3000‑05A) for customer complaints in detail and forward it to the workshop. Operation steps for the workshop employee: 1. Perform quick test 2. Access the transmission control unit via XENTRY Diagnosis 3. Select "A customer complaint has been received" and carry out all subsequent operation steps (IPR diagnosis path). 4. The IPR repair instructions are displayed, Carry out the IPR repair instructions without performing any further diagnostic or repair steps. ‑ Important: The IPR repair instructions are binding and must be carried out. Differing repairs are possible; such repairs must be documented in XENTRY in free text. Please observe the information regarding the IPR diagnosis process in XENTRY. Conventional diagnosis and subsequent appropriate repairs are only permitted if IPR does not specify any repair instructions. Invoicing for the guided IPR steps: Operation item 27‑0640 and 0.1 hours Notice regarding warranty: The use of IPR in association with warranty claims is mandatory! If the IPR repair instructions are disregarded without justification, the warranty claims may be rejected and/or are subject to debit. IPR will provide a measure to repair the vehicle based on various data sources (EEPROM, fault codes, etc). Please consider the vehicle maintenance record of the vehicle. For warranty and goodwill repairs, the transmission ECU test log and/or IPR test result must be uploaded into Paperless XENTRY Diagnosis (pXD) . If repair is being determined based of oil pan condition pictures of oil pan MUST be provided to warranty as justification. ·Tamper‑proof documentation: The IPR repair instructions are stored in the control unit log. Please file this document in a tamperproof manner ‑ either in digital form or as a hard‑copy printout and also enclose a printout with the damaged part. In this regard, please comply with the country‑specific warranty requirements of the MPC/general distributor.

Complaint Slight creaking noises when steering. Cause Noises may come from one or more sleeves of the horn contact plate. Remedy Remove the horn contact plate and check the sleeves for noise; see attached video. If necessary, apply lubricant to the sleeves.