Service bulletins for the 2021 Freightliner Sprinter
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.
87 on file from NHTSA, as of 2026-10-19.
About P206B on the 2021 Freightliner Sprinter: what the code means, and the bulletins and recalls about the same components.
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Only bulletins with trouble code: P206B are shown. Show all
| LI49-20-N-080376 | 2026-04-02. Service bulletin. FUEL/PROPULSION SYSTEM. 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 |
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| LI49-20-N-078838 | 2026-04-02. Service bulletin. FUEL/PROPULSION SYSTEM. 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-075995 | 2026-04-02. Service bulletin. UNKNOWN OR OTHER. Vehicles with SCR Generation 4: SCR/AdBlue® warning message cannot be reset with fault code P13DF00 or P300685 Complaint SCR or AdBlue warning message cannot be reset. All fault codes in the AdBlue (SCR) control unit have been processed and corrected, however fault codes P13DF00 or P300685 remain active and stored. Cause The procedure for resetting the SCR or AdBlue warning message with XENTRY Diagnosis has not been carried out. Note: If AdBlue quality or concentration related fault codes are present, such as P300494, P203B31, or P206B31, complete the applicable diagnostic procedure first. This includes the thaw, mixing drive, and retest requirements in LI49.20-N-080376 and the detailed diagnosis and re-pair steps in LI49.20-N-078838 as applicable. Do not attempt to reset the SCR or AdBlue warning message until the underlying fault condition has been corrected. Remedy Note: Do not replace any parts for an incorrectly executed reset procedure. 1. Connect the battery charger •Maintain adequate voltage throughout the procedure per applicable guidance. 2. Connect the diagnostic device •Use the latest version of XENTRY Diagnosis and Add-Ons. 3. Reset the SCR or AdBlue warning message using XENTRY Diagnosis •Quick test view → N118/5 – Selective Catalytic Reduction (SCR GEN4) → Special processes → Reset SCR/AdBlue® warning message. Note: Ensure all 5 listed processes are completed successfully, indicated by Actual value: "successfully completed". 4. Complete the disconnect and sleep mode initiation procedure •Disconnect XENTRY. •Refer to manual AD00.00-D-2000-06TS for the correct procedure to disconnect the diagnostic device from Model 907. •Disconnect the Battery Charger •Refer to manual AR54.10-D-1127TS for instructions on safely disconnecting the battery charger from Model 907. •Turn off the ignition. •Remove the key. •Lock the vehicle and wait approximately 15 minutes to allow the CAN bus system to enter sleep mode. 5. Post sleep mode vehicle start •After the 15-minute waiting period, start the vehicle. Note: The "starts remaining" message will remain on the Instrument Cluster (IC), but the vehicle will not be in the 5mph de-rate mode. 6. Drive for system self-test •Drive the vehicle for 5 to 10 miles to enable the SCR system to perform a self-test. Note: During the warning reset process, ensure the outside temperature sensor is reading above 10 degrees Fahrenheit. If not, keep the vehicle inside and repeat the reset. The vehicle may need to be driven to allow NOx sensors and the SCR system to complete their self-test before fault codes can be stored and then cleared. 7. Confirm and erase fault codes •Verify warning messages. •Ensure relevant fault codes are stored. •Erase fault memory if necessary. 8. Disconnect the Diagnostic Device •Refer to manual AD00.00-D-2000-06TS for the correct procedure to disconnect the diagnostic device from Model 907. 9. Disconnect the Battery Charger •Refer to manual AR54.10-D-1127TS for instructions on safely disconnecting the battery charger from Model 907. |
| LI4920N078838 | 2026-03-03. Service bulletin. ENGINE. 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 concentration of AdBlue is either above or below the Mercedes-Benz specifications, which can lead to premature freezing. C. Frozen or partially frozen AdBlue can cause the AdBlue level sensor to misread levels. D. The AdBlue level sensor is damaged. |
| LI49.20-N-078838 | 2025-04-03. Service bulletin. FUEL/PROPULSION SYSTEM. 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. |
| LI49.20-N-078838 | 2025-03-04. Service bulletin. FUEL/PROPULSION SYSTEM. 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. Remedy A. Software 1. Verify no newer software in AdBlue® SCR control unit (N118/5). 2. Complete LI49.20-N-075995 for Adblue warning reset. --NOTE-- If there is no updated software available, proceed to step B. B. Adblue Concentration 1. Verify the AdBlue concentration according to WIS AR49.20-D-9264TS - Check the concentration of AdBlue. --NOTE-- If the AdBlue concentration is below 31.8% or above 33.2%, it must be replaced. Please note that this will be at the customer's expense. 2. If the AdBlue concentration is within the approved specifications, please proceed to step C. C. Frozen Adblue or the SCR Actual Values state 'Frozen Adblue' 1. Check if the AdBlue is frozen. If it is, let the vehicle sit in a warm place overnight and recheck. 2. Have the vehicle running and XENTRY hooked up displaying Adblue level values 3. Drain the Adblue Tank and verify fill level reflects the change in the Adblue level 4. Fill the Adblue Tank SLOWLY and do not overfill, verify fill level reflects the change in the Adblue level --NOTE-- The Fill Level Sensor 1 functions as the "empty sensor." It accurately measures the bottom 60 mm (2.3 in- ches) of the AdBlue tank. Once the tank is filled beyond the 60 mm (2.3 inch) mark, the sensor may not read accura- tely, and you might notice the displayed value fluctuating. This behavior is normal, see attachment 'Fill Level 1'. 5. Reset the Adblue Tank fill level via XENTRY --NOTE-- If the XENTRY still shows that there is frozen Adblue or the concentration is still inaccurate after draining and filling, please refer to the attachments 'Adblue Frozen' and 'Adblue Concentration' and proceed to step C. 6. Complete LI49.20-N-075995 for Adblue warning reset. --NOTE-- If the steps above do not fix the vehicle, please proceed to step D. D. Damaged Adblue Level Sensor/Concentration Sensor 1. Replace the Adblue Tank 2. With the vehicle running and XENTRY hooked up displaying Adblue level values 3. Fill the Adblue Tank SLOWLY and do not overfill, verify fill level reflects the change in the Adblue level 3. Reset the Adblue Tank fill level via XENTRY 4. Complete LI49.20-N-075995 for Adblue warning reset. --NOTE-- During LI49.20-N-075995 for Adblue warning reset, please ensure that the outside temperature sensor is reading above 10 degrees Fahrenheit. If it is not, keep the vehicle inside the shop overnight. Complete LI49.20- N-075995 again. Additionally, please note that the vehicle may need to be driven to allow the NOx sensors and SCR system to complete their self-test. Once this is finished, the P13DF00 code should be stored and can then be cleared. --NOTE-- During cold weather, when temperatures are below 32 degrees Fahrenheit, please advise the client to keep the AdBlue tank fill level between 50% and 85%. This will allow for proper fluid expansion and help prevent damage to the level/concentration sensor. |
| LI49.20-N-078838 | 2025-02-04. Service bulletin. ENGINE. Check engine light or Adblue warning with fault codes P206B31, P203B31, or P300494 when outside temperatures are below 32 degrees Fahrenheit |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.