# Service bulletin LI49.20\-N\-073931

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.

- Type: Service bulletin
- NHTSA id: 10207197
- Published by NHTSA: 2022\-02\-04
- Manufacturer's number: LI49.20\-N\-073931
- Manufacturer's date: 2022\-01\-18
- NHTSA component: FUEL SYSTEM, DIESEL; ENGINE AND ENGINE COOLING

## NHTSA's summary

Complaint Thank you for your continued support of the US Emission Modification Program \(EMP\). We are providing this LI to assist you in addressing vehicles that come to your workshop to receive the Approved Emission Modification \(AEM\), but show in VMI as eligible only for the Canada BlueTEC II Field Measure or as currently registered in Canada. Only vehicles currently registered in the United States, or held by a US dealer, are eligible to receive the US Approved Emission Modification \(AEM\), including vehicles originally built for the Canadian market. This LI is intended to help you evaluate how to proceed when presented with such a vehicle. Complaint 1: VMI shows Canada BlueTEC II Field Measure AND vehicle is currently registered in Canada. Complaint 2: VMI shows Canada BlueTEC II Field Measure AND vehicle is currently registered in the US or held by a US auto dealer. Complaint 3: VMI shows US Approved Emission Modification \(AEM\) AND vehicle is currently registered in Canada. Cause Cause 1: Canadian client traveling in the US. Cause 2: Vehicle came from Canada, but is now registered in the US or held by a US auto dealer. Cause 3: Vehicle came from the US, but is now registered in Canada Remedy Remedy 1: Vehicles registered in Canada are not eligible for the US Approved Emission Modification \(AEM\). Refer the client to visit https://www.BlueTECSettlement.ca for further information and to determine eligibility. Remedy 2: Verify the vehicle is currently registered in the US, or is owned by a US auto dealer. Open a PTSS case with a reference to LI49.20\-N\-073931 and upload a copy of the vehicle's current US registration or proof of ownership by a US auto dealer. Further instruction will be provided by PTSS. Remedy 3: Verify the vehicle is currently registered in Canada. Vehicles registered in Canada are not eligible for the US Approved Emission Modification \(AEM\). To assist us with correcting VMI, please open a PTSS case with a reference to L

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2022/MC-10207197-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2022/MC-10207197-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Engine, Fuel system

## Vehicles listed

- 2017 to 2021 MERCEDES\-BENZ SPRINTER 1500
- 2017 to 2021 MERCEDES\-BENZ SPRINTER 2500
- 2017 to 2021 MERCEDES\-BENZ SPRINTER 3500
- 2017 to 2021 MERCEDES\-BENZ SPRINTER 4500

## Recalls for the same vehicles and component

- [23V444000](/recalls/nhtsa/23V444000.md), 2023-06-26: FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP
- [2023353](/recalls/tc/2023353.md), 2023-06-23: Fuel System
- [2020465](/recalls/tc/2020465.md), 2020-10-01: Fuel System
- [20V595000](/recalls/nhtsa/20V595000.md), 2020-09-29: FUEL SYSTEM, GASOLINE:DELIVERY:HOSES, LINES/PIPING, AND FITTINGS
- [20V453000](/recalls/nhtsa/20V453000.md), 2020-08-04: FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP
- [2020059](/recalls/tc/2020059.md), 2020-02-13: Engine
- [2020058](/recalls/tc/2020058.md), 2020-02-13: Engine
- [20V079000](/recalls/nhtsa/20V079000.md), 2020-02-12: ENGINE AND ENGINE COOLING:EXHAUST SYSTEM
- [20V078000](/recalls/nhtsa/20V078000.md), 2020-02-12: ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:GAS RECIRCULATION VALVE \(EGR VALVE\); ENGINE AND ENGINE COOLING:EXHAUST SYSTEM
- [2019563](/recalls/tc/2019563.md), 2019-11-08: Fuel System

## Other bulletins for the same vehicles and component

- [Exhaust System](/bulletins/11036889.md), 2026-09-04, Warranty extension: ENGINE. Mercedes\-Benz AG \(“MBAG”\), the manufacturer of Freightliner Sprinter vehicles, has determined that on certain MY17\-18 Freightliner Sprinter vehicles, the diesel particulate filter may crack due to an insufficient weld. MBAG also determined that specific environmental influences in the form of corrosion could have a negative effect on the long\-term durability of the diesel particulate filter. This can lead to stresses within the exhaust system which could cause the diesel particulate filter to crack. In addition, in individual cases, it is possible that during repairs to the exhaust system that were unrelated to a defect of the diesel particulate filter, the exhaust system was not replaced in accordance with the MBAG specifications. Specifically, the issue might have arisen where it was necessary for the workshop to replace the exhaust system \(including the diesel particulate filter\) but that the replacement system was not fitted according to MBAG specifications. This could lead to stresses within the exhaust system which may also cause the diesel particulate filter to crack. In both cases, a fault code is stored in the engine control unit software and the engine diagnostics warning lamp \(MIL\) is activated. The driver would become aware of the issue due to noise from the exhaust system.
- [LI07\_02\-N\-079573\_2\_en](/bulletins/11036846.md), 2026-09-03, Service bulletin: FUEL/PROPULSION SYSTEM. Oil Leak at Crankcase Near the High\-pressure Fuel Pump OM654 Complaint Visible oil leak at the crankcase near the mounting area of the high‑pressure fuel pump on OM654 engines. Cause Oil leakage near the high‑pressure fuel pump may result from insufficient sealing performance of the jump shaft seal and/or reduced sealing effectiveness at the interface between the high‑pressure fuel pump and crankcase. Relative movement of the high‑pressure fuel pump within the crankcase bore may reduce sealing effectiveness at the pump‑to‑crankcase interface and promote oil migration during engine operation. Remedy Install a new high‑pressure fuel pump together with the design‑optimized sealing ring.
- [LI49.10\-N\-080528](/bulletins/11034416.md), 2026-07-02, Service bulletin: FUEL/PROPULSION SYSTEM. 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\-069565](/bulletins/11034411.md), 2026-07-02, Service bulletin: FUEL/PROPULSION SYSTEM. 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\_4](/bulletins/11033165.md), 2026-06-02, Service bulletin: FUEL/PROPULSION SYSTEM. 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.
- [LI4910\-N\-060969](/bulletins/11031943.md), 2026-05-02, Service bulletin: ENGINE. Complaint Rattling noise from underneath the vehicle. Cause One or more of the following conditions may be present: 1. The exhaust bracket from the DPF to the transmission is cracked or broken. • See Pic. 1 for an example of a broken bracket. 2. Transmission bell housing cracked or broken at the exhaust mounting area. • See Pic. 2 for an example of bell housing damage. 3. Exhaust bracket from DPF to engine \(cylinder crankcase\) cracked or broken. • See EPC OM651 \#217 for bracket location. 4. Diesel Particulate Filter \(DPF\) pipe cracked at a weld joint. • Cracking may be present at bracket welds or along the DPF housing seams. • This can cause rattling noises and secondary exhaust bracket stress. • Perform a visual inspection of the DPF pipe and weld joints. Remedy Inspect all related components and repair or replace as required. Inspection and Repair 1. Inspect the exhaust bracket from the DPF to the transmission. • Check the bracket for cracks or complete separation. • See Pic. 1 for a failed example. • See EPC OM651 \#550 and Pic. 3 for bracket location. • If damaged, replace the bracket. • See Pic. 4, Pic. 5, and Pic. 6 for the updated bracket design and identification. 2. Inspect the transmission bell housing. • Inspect the bell housing at the exhaust mounting point for cracks or structural damage. • See Pic. 2 for an example of bell housing damage. • Replace the transmission if damage is confirmed. 3. Inspect the exhaust bracket from the DPF to the engine \(cylinder crankcase\). • Inspect the bracket for cracks or broken mounting points. • See EPC OM651 \#217 for bracket location. • Replace the bracket if damaged. 4. Inspect the DPF pipe. • Inspect the DPF for cracks at weld joints, especially near mounting points. • If cracking is found, replace per current aftertreatment guidelines. Correct positioning and tightening of the exhaust system are critical to prevent repeat failures. Positioning the Exhaust System 1. Position and align the exhaust system before tightening. • Support and fit the exhaust system in its installed position. • Push the exhaust system forward. • Install the DPF‑to‑transmission bracket and lightly tighten the mounting bolt. • Install the engine mount and V‑mount bolts by hand, approximately two turns. • See “Positioning of the exhaust system” image. Tightening Sequence 1. Tighten the exhaust system in the correct sequence. • Tighten engine mounting bolts to 25 Nm. • Tighten V‑mount bolts to 25 Nm. • Tighten exhaust bracket bolts to 15 Nm. • See “Tightening sequence of the exhaust system” image. 2. Verify mounting bolt locations. • Confirm correct mounting screw positions at the transmission bracket. • See Pic. 7 and Pic. 8 for mounting screw locations.
- [LI4700N069565](/bulletins/11031942.md), 2026-05-02, Service bulletin: FUEL/PROPULSION SYSTEM. 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\-080376](/bulletins/11030629.md), 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
- [LI49\-20\-N\-078838](/bulletins/11030627.md), 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.
- [LI4920N078838](/bulletins/11029273.md), 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.

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