P206B · Manufacturer communications

DODGE, FREIGHTLINER, MERCEDES-BENZ · 2026-03-23

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…

FREIGHTLINER, MERCEDES-BENZ · 2026-03-23

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 Cause A. The software for the AdBlue (SCR) control unit (N118/5) is outdated.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…

FREIGHTLINER, MERCEDES-BENZ · 2026-03-23

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…

FREIGHTLINER, MERCEDES-BENZ · 2026-02-24

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…

FREIGHTLINER, MERCEDES-BENZ · 2025-03-18

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…

DODGE, FREIGHTLINER, MERCEDES-BENZ · 2025-02-04

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…

FREIGHTLINER, MERCEDES-BENZ · 2025-02-04

Check engine light or Adblue warning with fault codes P206B31, P203B31, or P300494 when outside temperatures are below 32 degrees Fahrenheit

FORD · 2024-08-22

Some 2023-2024 F-Super Duty vehicles built on or before 22-Jul-2024 and equipped with a 6.7L engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P203B, P206B, and/or P2201:92 stored in the powertrain control module (PCM). This may be due to the software in the PCM. To correct the condition, follow the Service Procedure to reprogram the PCM using the latest software level of the Ford Diagnosis and Repair System (FDRS) scan tool.

FORD · 2024-08-22

Some 2024-2025 F-650/F-750 vehicles built on or before 22-Jul-2024 and equipped with a 6.7L engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) P203B, P206B, and/or P2201:92 stored in the powertrain control module (PCM). This may be due to the software in the PCM. To correct the condition, follow the Service Procedure to reprogram the PCM using the latest software level of the Ford Diagnosis and Repair System (FDRS) scan tool.

FORD · 2024-02-27

Some 2023-2024 F-Super Duty vehicles equipped with a 6.7L engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) U02A2, P206B, P203B, P208A, P20FA, P20FD, and/or P20FC stored in the powertrain control module (PCM). Before performing normal diagnostics, inspect connectors C1273C (32 pin) and C406 (14 pin) for proper connection. Also disconnect and inspect C1415 (32 pin), C406 (14 pin), C4863 (7 pin) and C4864 (5 pin) on the 14405 vehicle harness for signs of terminal push out, water intrusion and/or corrosion. Refer to the Wiring Diagram for connector locations. Repair as necessary. Refer to Wiring Diagram Cell 005 for repair procedures.

FORD · 2023-08-28

Some 2023 F-Super Duty vehicles equipped with a 6.7L engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) U02A2, P206B, P203B, P208A, P20FA, P20FD, and/or P20FC stored in the powertrain control module (PCM). Before performing normal diagnostics, inspect connectors C1273C (32 pin) and C406 (14 pin) for proper connection. Also disconnect and inspect C1415 (32 pin), C406 (14 pin), C4863 (7 pin) and C4864 (5 pin) for signs of water intrusion and/or corrosion. Refer to the Wiring Diagram for connector locations. Repair as necessary. Refer to Wiring Diagram Cell 005 for repair procedures.

FORD · 2023-08-28

Some 2024 F-650/F-750 vehicles equipped with a 6.7L engine may exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTC) U02A2, P206B, P203B, P208A, P20FA, P20FD, and/or P20FC stored in the powertrain control module (PCM). Before performing normal diagnostics, inspect connectors C1273C (32 pin) and C314 (14 pin) for proper connection. Also disconnect and inspect C1583 (32 pin), C314 (14 pin), C3616 (7 pin) and C3613 (5 pin) for signs of water intrusion and/or corrosion. Refer to the Wiring Diagram for connector locations. Repair as necessary. Refer to Wiring Diagram Cell 005 for repair procedures.

MERCEDES-BENZ · 2022-07-01

Complaint Indicator lamp illuminates in instrument cluster, fault codes P203B31, P203B49 and P206B31 present in AdBlue® (SCR) control unit (N118/5). Cause Software for AdBlue® (SCR) control unit (N118/5) Remedy Update AdBlue Control Unit Software

MERCEDES-BENZ · 2020-07-08

Check engine light illuminates in instrument cluster, fault codes P203B31 or P203B49 or P206B31 present in AdBlue(R) (SCR) control unit

MERCEDES-BENZ · 2020-04-23

Check engine light on with fault codes P203B31, P203B49, P206B31, P13DF00 present in the SCR control unit

CHEVROLET, GMC · 2018-12-10

This Preliminary information communicates to the dealer technicians that DTCs P0046, P113B and P206B may be caused by a software anamoly. The anamoly should be corrected by updating the engine control module (ECM).

CHEVROLET, GMC · 2018-04-19

This Bulletin provides starting point information to diagnose DTC P206B.

CHEVROLET · 2018-02-22

This engineering informational bulletin is requesting information from the field on vehicles that have the condition of Malfunction Indicator Lamp Illuminated with DTC P21A9, P203B, or P206B Set.

HINO · 2016-01-11

SB-16-004 1. In the event that a subject vehicle exhibits an illuminated check engine lamp and DTC?s P2201, P2214, P206B, P207F, or P20EE are stored in the DCU, the NOX sensor may have failed due to a cracked NOX sensor heating element. Follow the revised Workshop Manual diagnostic procedure to determine if the NOX sensor has failed. 2. Enhanced DCU software is available to prevent the NOX sensor heating element from cracking due to exposure of condensation on the heating element. 3. The enhanced DCU software will also prevent false detections of DTC P142A being set in the DCU.

HINO · 2015-11-17

SB-15-038 1. In the event that a subject vehicle exhibits an illuminated check engine lamp and DTC?s P2201, P2214, P206B, P207F, or P20EE are stored in the DCU, the NOX sensor may have failed due to a cracked NOX sensor heating element. Follow the revised Workshop Manual diagnostic procedure to determine if the NOX sensor has failed.