Overview
| CODE | REASON | EFFECT |
| Fault Code: 6767 PID: SPN: 3521 FMI: 11/31 LAMP: None SRT: |
The Urea Quality Sensor has been unable to generate a concentration value for a period of time.
|
Engine power derate. |
Circuit Description
The DEF quality sensor is a smart device and communicates with the engine 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 Engine Control Module (ECM) lost communication with the aftertreatment DEF quality sensor via the J1939 data link.
Action Taken When the Fault Code is Active
- The ECM illuminates the Malfunction Indicator Lamp (MIL) after the diagnostic fails on two consecutive trips .
- Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.
- Engine torque will be severely reduced if the engine is operated for an extended period of time with this fault active.
Conditions for Clearing the Fault Code
- To validate the repair, start the engine and let it idle for up to 5 minutes.
- The ECM will turn off the amber CHECK ENGINE lamp and/or MIL immediately after the diagnostic runs and passes.
- The fault code status displayed by the recommended Cummins® electronic service tool or equivalent will change to INACTIVE immediately after the diagnostic runs and passes.
- The “Reset All Faults” command in the recommended Cummins® electronic service tool or equivalent 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:
- Low aftertreatment diesel exhaust fluid level in the diesel exhaust fluid tank
- Shorted or open J1939 data link wiring.
- Malfunctioning Aftertreatment DEF Quality Sensor.
- Inactive counts can be caused by elevation changes or tank sloshing while driving.
Troubleshooting Summary
Solution: S00000563
Verification
Conditions
- Turn keyswitch OFF.
Action
- Inspect the aftertreatment diesel exhaust fluid in the tank for signs of debris or contamination.
- Use a diesel exhaust fluid refractometer to measure the concentration of the diesel exhaust fluid in the tank.
Specification
- If there are signs of contaminates in the aftertreatment diesel exhaust fluid, then proceed to the Repair section.
Linked Solutions
- None
Repair
- Drain the diesel exhaust fluid tank, clean thoroughly and refill with pure diesel exhaust fluid.
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00000443
Verification
Conditions
- Connect all components.
- Turn keyswitch ON.
- Connect the recommended Cummins® electronic service tool or equivalent.
Action
- Use the recommended Cummins® electronic service tool or equivalent to read the fault codes.
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revision listed in the ECM calibration revision history for applicable changes.
Specification
- If a calibration update for this fault code is available, the ECM calibration revision must be that revision or higher.
Linked Solutions
- None
Repair
- Prior to downloading the ECM calibration, check to see that all job images and all other troubleshooting has been documented as downloading an ECM calibration will remove the fault codes on the ECM.
- Download the updated ECM calibration code.
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00000933
Verification
Conditions
- Turn keyswitch ON.
- Connect the recommended Cummins® electronic service tool or equivalent.
Action
- Use the recommended Cummins® electronic service tool or equivalent to read the fault codes.
- Verify all preceding solution verifications for this fault code have been performed.
Specification
- If the fault code is still active or inactive with more than once count within the last 25 engine hours and all the preceding solution verifications have been performed, then a malfunctioning aftertreatment diesel exhaust fluid quality sensor has been detected.
Linked Solutions
- None
Repair
- Replace the aftertreatment diesel exhaust fluid quality sensor.
Refer to OEM Service Manual
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.