Cummins X15 CM2350 X116B Performance Series (2018 & Newer) Fault Code: 6766 PID: SPN: 3521 FMI: 18 Aftertreatment 1 Diesel Exhaust Fluid Property- Data Valid But Below Normal Operating Range- Moderately Severe Level - EcuForce Truck (2025)

Table of Contents
Related Related products

Shop

Account

Cart$0.00

Subtotal: $0.00

No products in the cart.

Circuit Description
The DEF quality sensor is a smart device and communicates with the engine electronic control module (ECM) via the J1939 data link. The DEF quality sensor receives power and ground directly from the battery. The sensor performs its own internal diagnostics and reports malfunctions back to the primary engine ECM via the J1939 data link. The DEF quality sensor is used to measure the concentration of the DEF in the tank.

Component Location
The aftertreatment diesel exhaust fluid quality sensor is located in the aftertreatment diesel exhaust fluid tank. It may be a combination sensor with the aftertreatement diesel exhaust fluid tank level and tank temperature sensors. Location of the tank and sensor is OEM dependent. Refer to the OEM service manual.

Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes
The DEF quality sensor has detected that the DEF concentration has fallen below a critical threshold.

Action Taken When the Fault Code is Active
The ECM illuminates the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
Diesel exhaust fluid injection into the aftertreatment system is disabled.
Conditions for Clearing the Fault Code
Start and idle the engine for 15 minutes.
For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk
Possible causes of this fault code include:

Degraded, diluted, or incorrect diesel exhaust fluid
Malfunctioning Aftertreatment DEF Quality Sensor.

Possible Cause:
1) DEF fluid
2) ECM calibration

Related

Categories Cumminz, DTC TRUCKS, Tags , 1, 18, 2018, 3521, 6766, Aftertreatment, Below, But, CM2350, Code, Cummins, Data, Diesel, Exhaust, Fault, Fluid, FMI, Level, Moderately, Newer, Normal, Operating, Performance, PID, Property-, Range-, Series, Severe, SPN, Valid, X116B, X15

Wiring Diagrams

Component Locators

  • Volvo PROSIS Offline 2019 Parts Catalog Installation Service

    Trucks software$45.00

    Rated 0 out of 5

  • John Deere$200.00

    Rated 0 out of 5

  • DOOSAN DMS-5 3.1.3 [2023.11] diagnostic software 1PC

    DOOSAN$106.00

    Rated 0 out of 5

  • ZF Testman Pro ESB 10.5 2022

    Trucks software$200.00

    Rated 0 out of 5

  • Scania$30.00

    Rated 0 out of 5

  • AGCO EDT 2023.10 Electronic Diagnostic Tool 1.125

    AGCO$120.00

    Rated 0 out of 5

  • JCB ServiceMaster 4 v21.4.2 [05.2021] Diagnostic Software

    JCB$85.00

    Rated 0 out of 5

  • CAT$50.00

    Rated 0 out of 5

  • Allison Doc Premium Update 2023 v2

    Allison$102.00

    Rated 0 out of 5

  • CAT ET Electronic Technician 2019C

    CAT$40.00

    Rated 0 out of 5

  • Thermo King EPC 2012

    Thermo King$45.00

    Rated 0 out of 5

  • Volvo Intermediate Storage File Encryptor/Decryptor (Editor) VISFED 0.3.2

    Trucks software$35.00

    Rated 0 out of 5

  • DOWNLOAD VOLVO MATRIS 2.3.3

    Trucks software$60.00

    Rated 0 out of 5

  • download Hitachi Construction Machinery MPDr Ver 3.7.0.0 [10.2020] Diagnostic Software

    Hitachi$76.00

    Rated 0 out of 5

  • ZF Testman Pro ESB 10.5 2022

    Trucks software$200.00

    Rated 0 out of 5

  • JPRO Diagnostic Software Download 2024

    JPRO$100.00

    Rated 0 out of 5

  • Navkal 2018 offline version remove DPF MAXXFORCE 13 EPA 10

    Navistar$80.00

    Rated 0 out of 5

  • Hino DX3 1.22.10 2022 ( 1 PC )

    Hino$96.00

    Rated 0 out of 5

  • NAVISTAR ENGINE CYLINDER PERFORMANCE ANALYZER V7.8.8.1

    Navistar$52.00

    Rated 0 out of 5

  • Cumming Caltem 5.9.1 2022 ( 1 PC )

    cummisznn$78.00

    Rated 0 out of 5

Related products

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • PACCAR PX-9 CM2350 (2013-17) Fault Code:3634 PID: SPN:5484 FMI:4 Engine Fan Clutch 2 Control Circuit – Voltage Below Normal or Shorted to Low Source

    DTC TRUCKS

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • Bendix ABS EC-30 Fault Code: SID 251 FMI 3

    Bendix ABS

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • 1000 & 2000 Gen 4$50.00

    Rated 0 out of 5

  • SERVICE MANUAL HINO FD.FE.FF.SG 2003

    HINO$37.00

    Rated 0 out of 5

  • service manual TroubleshootingManual Allison TransmissionMD/HD/B -Series -TransmissionsWTEC II Controls

    Allison$25.00

    Rated 0 out of 5

  • SERVICE MANUAL DETROIT DIESE LDDEC VI – CPC Vehicle Interface Harness Schematic

    DETROIT$15.00

    Rated 0 out of 5

  • SERVICE MANUAL EATON Gen 2 – Automated Transmissions

    EATON$28.00

    Rated 0 out of 5

  • CARRIE$20.00

    Rated 0 out of 5

  • SERVICE MANUAL BOBCAT 425-428 sms

    BOBCAT$57.00

    Rated 0 out of 5

  • SERVICE MANUAL BOBCAT 540 543 sms

    BOBCAT$50.00

    Rated 0 out of 5

  • SERVICE MANUAL DETROIT Diesel-Ash Accumulator Reset (2 02-10 Rev)

    DETROIT$15.00

    Rated 0 out of 5

  • SERVICE MANUAL Carrie TEMPRA 440S SERIES

    CARRIE$20.00

    Rated 0 out of 5

  • SERVICE MANUAL Eaton Fuller® HD FR/FRO TransmissionsTRSM2400April 2013

    TRUCK MANUALS

    Rated 0 out of 5

Cummins X15 CM2350 X116B Performance Series (2018 & Newer) Fault Code: 6766 PID: SPN: 3521 FMI: 18 Aftertreatment 1 Diesel Exhaust Fluid Property- Data Valid But Below Normal Operating Range- Moderately Severe Level - EcuForce Truck (2025)
Top Articles
Latest Posts
Recommended Articles
Article information

Author: The Hon. Margery Christiansen

Last Updated:

Views: 6059

Rating: 5 / 5 (50 voted)

Reviews: 81% of readers found this page helpful

Author information

Name: The Hon. Margery Christiansen

Birthday: 2000-07-07

Address: 5050 Breitenberg Knoll, New Robert, MI 45409

Phone: +2556892639372

Job: Investor Mining Engineer

Hobby: Sketching, Cosplaying, Glassblowing, Genealogy, Crocheting, Archery, Skateboarding

Introduction: My name is The Hon. Margery Christiansen, I am a bright, adorable, precious, inexpensive, gorgeous, comfortable, happy person who loves writing and wants to share my knowledge and understanding with you.