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Service bulletin MB Initial NCU

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10241385
Published by NHTSA2023-08-28
Manufacturer's numberMB Initial NCU
Manufacturer's date2023-07-05
NHTSA componentFUEL SYSTEM, OTHER:DELIVERY

NHTSA's summary

Replace Fuel Delivery Module.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Fuel system

Vehicles listed
MERCEDES-BENZ METRIS2021, 2022
MERCEDES-BENZ SPRINTER 15002021, 2022 (the catalog's model; the bulletin names a series or trim of it)
MERCEDES-BENZ SPRINTER 25002021, 2022 (the catalog's model; the bulletin names a series or trim of it)
MERCEDES-BENZ SPRINTER 35002021, 2022 (the catalog's model; the bulletin names a series or trim of it)
MERCEDES-BENZ SPRINTER 45002021, 2022 (the catalog's model; the bulletin names a series or trim of it)

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
23V8810002023-12-21. FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP
20236722023-12-15. Fuel System
23V4440002023-06-26. FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP
20233532023-06-23. Fuel System
22V1340002022-03-08. FUEL SYSTEM, GASOLINE:DELIVERY:HOSES, LINES/PIPING, AND FITTINGS
20221032022-03-07. Fuel System

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
LI49.10-N-0805282026-07-02. Service bulletin. OM642 DPF Filter Cracked or Broken Complaint Vehicle will not start or exhibits noisy exhaust. Check Engine Lamp (CEL) is on. Multiple control unit communication and system faults may be present, including but not limited to: 134800, 134900, 11B300, 11EC00, 15E100, 155700, 162500. Additional events codes may include: 134300, 102200, 163400, 16CE00. In many cases, multiple unrelated faults are stored due to electrical disruption from wiring damage rather than indivi-dual component failure. Cause The DPF filter is cracked, broken, or leaking, allowing hot exhaust gas to escape from the exhaust system. Depending on the location of the break or leak, hot exhaust gas may be directed toward the main wiring harness and/ or the SCR (Selective Catalytic Reduction) dosing valve assembly. This heat exposure can result in: • Internal melting of wiring insulation within the harness • Short to ground conditions and loss of communication between control units • Damage to the dosing valve and/or heated AdBlue line Damage to the wiring harness may not be visible externally, as the outer tape can remain intact while the internal wires are melted and fused together. Remedy Inspect the DPF assembly for cracks, separation, or leakage. Do not proceed with further diagnosis or component replacement until the exhaust leak source has been identified and confirmed. If any damage is found, replace the DPF filter assembly. Based on the location of the failure, inspect all components in the path of the exhaust leak, including the dosing valve assembly and main wiring harness. The wiring harness must be opened in any area exposed to the exhaust leak to visually inspect the individual wires. External inspection alone is not sufficient to determine harness condition. Repair or replace any damaged wiring in accordance with approved repair procedures. Replace any dosing system components that show signs of heat damage. Failure to identify and repair all heat-affected components will result in repeat faults or no-start conditions.
LI47_00-N-0695652026-07-02. Service bulletin. Fuel Level Unchanged After Refueling Complaint The customer reports that the fuel gauge shows inaccurate readings or remains unchanged after refueling. Cause A. The Fuel Supply Control Unit (FSCU) fails to detect a refueling event B. The Fuel Level Sensor provides incorrect readings due to mechanical interference or installation issues
LI49.20-N-078466_42026-06-02. Service bulletin. Check engine light with fault code P3005CA in MRD1 (CDI) Complaint The check engine light is on, with a possiblility in a reduction of power and the presence of soot in the exhaust system. Fault code P3005CA: The diesel particulate filter efficiency is insufficient. Additional information: Additional fault codes may be present, related to the Diesel Particulate Filter (DPF) system or the Exhaust Gas Recirculation (EGR) system. Cause This fault code sets due to the following factors: 1. Damage to the Diesel Particulate Filter (DPF) unit. 2. The N74 (Soot Particulate Sensor Control Unit) identifies soot or debris located downstream of the SCR Catalyst (underbody). Remedy Note: The guided tests for fault code P3005CA have been revised in the XENTRY unit. It is important to complete these guided tests thoroughly. TIPS cases are NO longer required unless there is an absence of soot at the outlet of the Diesel Particulate Filter (DPF) unit. If there are any other fault codes present for component 'N74 (Soot Particulate Sensor Control Unit)', process these first. 1. Damage to the Diesel Particulate Filter (DPF) unit. • Complete the XENTRY guided tests: • Check the Exhaust system for leaks - Perform a visual inspection of the exhaust system from the Combustion Engine to Diesel Particulate Filter (DPF). Verify that there are no external damages and that all clamps and sensors are installed and leak-free. • Check component 'Exhaust pipe and Filter screen of Exhaust Gas Recirculation (low pressure)' for carbon fouling. If no soot is present at the Tailpipe outlet, recommended to separate the exhaust pipe downstream of the Diesel Particulate Filter (DPF) at the outlet to inspect.
LI47.50-N-072080_42026-06-02. Service bulletin. Check engine light on and FC P146264 stored in engine and fuel pump control units Complaint Check engine light active and FC P146264 Temp. and pressure sensor B4/15 is stored in Engine control unit and Fuel pump control unit. Cause Software parameter in Fuel pump control unit. Remedy Update fuel pump control unit (FSCU) to software version A0009024488 A0009030664. Clear fault codes and check for any additional symptoms.
LI4700N0695652026-05-02. Service bulletin. Complaint The customer reports that the fuel gauge shows inaccurate readings or remains unchanged after refueling. Cause A. The Fuel Supply Control Unit (FSCU) fails to detect a refueling event. B. The Fuel Level Sensor provides incorrect readings.
LI49-20-N-0803762026-04-02. Service bulletin. The check engine light is illuminated, or the AdBlue warning is active, with recorded faults related to AdBlue quality or concentration. Complaint Customer reports an illuminated check engine light and or an AdBlue system warning indicating AdBlue quality out of specification. The vehicle may enter reduced performance mode. One or more of the following fault codes related to the AdBlue tank may be stored: P206B31: Malfunction of the concentration sensor for AdBlue; the signal is absent. P203B31: Malfunction of the AdBlue fill level sensor; the signal is absent. P300494: The quality of the AdBlue is insufficient. Background AdBlue must meet ISO 22241 quality requirements. ISO 22241 urea content limits for AdBlue are 31.8 percent to 33.2 percent by mass. AdBlue begins to crystallize and freeze at approximately 12 degrees F. Freeze-thaw does not degrade the product when uncontaminated, and the bulk concentration returns to normal after complete thaw and mixing. Cause In cold soak conditions and during freeze thaw exposure, the tank contents may not be uniform at the time of sampling or system checks. During freezing and partial thaw, ice formation can temporarily create concentration gradients in the tank. As a result, urea percent readings can vary based on sample location and the state of thaw and mixing, which can produce apparent out of range readings even though the bulk fluid returns to normal after mixing. Remedy Testing Do not use a single urea percent reading taken from frozen, partially frozen, or not fully mixed AdBlue to make a repair or responsibility decision. Confirm full thaw and ensure tank contents are mixed before sampling. 1. Confirm full thaw - Confirm the AdBlue tank and associated components are fully thawed before sampling. - Do not sample slushy or partially frozen fluid. 2. Mix tank contents - Perform a road drive intended to mix the tank contents before sampling. - Idle time alone is not a reliable substitute for mixing. 3. Sample and measure - Take the sample and measure with the MB refractometer per the MB tool instructions. - Record the urea percent value. 4. Interpret the result against ISO 22241 limits - Within specification is 31.8 percent to 33.2 percent urea by mass. 5. Repeat if out of specification - If out of specification, repeat after an additional mixing drive to reduce sampling variation. - If still out of specification after full thaw, mixing, and repeat measurement, treat as a true out of specification result and proceed with further diagnosis per applicable MB guidance. Acceptance criteria AdBlue is within the ISO 22241 specification when the urea percent is between 31.8 percent and 33.2 percent by mass. Values outside this range are out of specification and require further diagnosis after completing the full thaw and mi-xing procedure above. Cross reference For vehicles with fault codes P206B31, P203B31, or P300494, refer to LI49.20-N-078838 for the detailed diagnostic and repair procedure. If a SCR or AdBlue warning reset is required after correction, refer to LI49.20-N-075995. Complete the diagnostic and corrective steps first. Perform the warning reset only after the underlying fault condition has been corrected. Warranty information and claim handling
LI49-20-N-0788382026-04-02. Service bulletin. Check engine light or Adblue warning with fault codes P206B31, P203B31, or P300494 present in AdBlue (SCR) control unit (N118/5) Complaint The check engine light or AdBlue warning is activated, accompanied by one or more of the following fault codes related to the AdBlue tank: P206B31 Malfunction of the concentration sensor for AdBlue; the signal is absent. P203B31 Malfunction of the AdBlue fill level sensor; the signal is absent. P300494 The quality of the AdBlue is insufficient. Cause A. The software for the AdBlue (SCR) control unit (N118/5) is outdated. B. The AdBlue concentration is outside ISO 22241 limits (below 31.8 percent or above 33.2 percent). C. Frozen or partially frozen AdBlue can cause the AdBlue level and concentration functions to report inaccurate values. D. The AdBlue level and concentration sensing functions in the tank are damaged. E. Cold soak and freeze thaw exposure can temporarily create concentration gradients in the tank and lead to sampling dependent readings until fully thawed and mixed. Important Before evaluating any AdBlue concentration result, follow LI49.20-N-080376 to confirm full thaw, perform a mixing drive, and retest. Do not use a single urea percent reading taken from frozen, partially frozen, or not fully mixed AdBlue for a repair or responsibility decision. Remedy A. Software 1. Verify no newer software is available for the AdBlue (SCR) control unit (N118/5). 2. If a software update is available, program the control unit per XENTRY guidance. 3. Only after the system is in proper working condition, complete LI49.20-N-075995 for AdBlue warning reset. Note: If there is no updated software available, print the XENTRY screen indicating this and proceed to section B. B. AdBlue concentration 1. Confirm full thaw and mixing per LI49.20-N-080376, then verify AdBlue concentration. a. Check concentration using the MB refractometer per the MB tool instructions and applicable WIS guidance. b. Use freeze frame data when applicable. 2. If AdBlue concentration remains below 31.8 percent or above 33.2 percent after full thaw, mixing drive, and retest, AdBlue replacement is required. Warranty and responsibility decisions must follow LI49.20-N-080376 warranty handling guidance and standard war-ranty policy. 3. If AdBlue concentration is within specification, proceed to section C. C. Frozen AdBlue or SCR actual values indicate frozen AdBlue 1. Check if AdBlue is frozen. If frozen, allow the vehicle to sit in a warm environment overnight and recheck. 2. With the vehicle running and XENTRY connected, display the actual AdBlue level values. 3. Drain the AdBlue tank and verify the displayed fill level reflects the change. 4. Fill the AdBlue tank slowly. Do not overfill. Verify the fill level reflects the change. Note: For model years 23 to 25, Fill Level Sensor 1 functions as the empty sensor and accurately measures only the bottom portion of the tank. Once the level is above the measurement range, the displayed value may fluctuate. This is nor-mal. 5. Reset the AdBlue tank fill level via XENTRY. Print the XENTRY pages showing that the fill up completed success-fully. 6. Only after the system is in proper working condition, complete LI49.20-N-075995 for AdBlue warning reset and print the XENTRY pages confirming the reset completed successfully. Note: If XENTRY still indicates frozen AdBlue or the concentration remains inaccurate after drain and refill and the thaw, mix, retest requirements were completed, proceed to section D. D. Damaged AdBlue level and concentration sensing functions 1. Replace the AdBlue tank as required by applicable MB guidance. 2. With the vehicle running and XENTRY connected, display the actual AdBlue level values. 3. Fill the AdBlue tank slowly. Do not overfill. Verify the fill level reflects the change. 4. Reset the AdBlue tank fill level via XENTRY. 5. Only after the system is in proper working condition, complete LI49.20-N-075995 for AdBlue warning reset.
LI49.20-N-0788382025-04-03. Service bulletin. Check engine light or Adblue warning with fault codes P206B31, P203B31, or P300494 when outside temperatures are below 32 degrees Fahrenheit. SCR Gen4 (KP7) Complaint: The check engine light or AdBlue warning is activated, accompanied by one or more of the following fault codes rela- ted to the AdBlue tank: P206B31: Malfunction of the concentration sensor for AdBlue; the signal is absent. P203B31: Malfunction of the AdBlue fill level sensor; the signal is absent. P300494: The quality of the AdBlue is insufficient. Cause: A. The software for the AdBlue (SCR) control unit (N118/5) is outdated. B. The concentration of AdBlue is either above or below the Mercedes-Benz specifications, which can lead to prema- ture freezing. C. Frozen or partially frozen AdBlue can cause the AdBlue level sensor to misread levels. D. The AdBlue level sensor is damaged.
LI47.10-N-0790102025-04-03. Service bulletin. Procedure for When Diesel Fuel Tank is Filled with Incorrect Fuel Type Complaint: Procedure for When Diesel Fuel Tank is Filled with Incorrect Fuel Type (e.g., gasoline, water, biodiesel, AdBlue/DEF) Cause: The incorrect fuel type, such as gasoline, water, biodiesel, or AdBlue/DEF has been added to the fuel system.
LI14.20-N-0738672025-04-03. Service bulletin. EGR Valve Diagnosis and Cleaning Procedure Complaint A: The engine is jolting/bucking between 1700 and 1900 rpm. Complaint B: One or more mechanical related fault codes for EGR Valve stored in CDI control unit, with possible Check Engine Light. Review list of mechanical fault codes in table below. NOTE: If one or more electrical related fault codes for EGR Valve are also present in CDI, utilize Complaint C. Review list of electrical fault codes PDF document in attachments. Complaint C: One or more electrical related fault codes for EGR Valve stored in CDI control unit, with possible Check Engine Light. Review list of electrical fault codes PDF document attached. Operation Text: 1. Diagnosis of EGR Valve related concerns including CEL, or drivability concern. 2. Clean EGR Valve. 3. Remove and re-install EGR Valve. 4. Quick Test