Overview

 

CODE REASON EFFECT
Fault Code: 3681
PID: 
SPN: 3228
FMI: 2/2
LAMP: Amber
SRT: 

 

The aftertreatment outlet NOx sensor indicates that the power supply to the sensor is incorrect.

 

 

None on performance.

Circuit Description

The aftertreatment outlet NOx (nitrogen oxides) sensor is a smart device and communicates with the engine control module (ECM) via the J1939 data link. The aftertreatment outlet NOx sensor performs its own internal diagnostics and reports malfunctions back to the primary ECM using the J1939 data link. The NOx sensor is permanently attached to the NOx control module. They are serviced as a single component and can not be replaced individually. The aftertreatment outlet NOx sensor is used to measure the NOx emissions at the outlet of the aftertreatment system.

Component Location

The aftertreatment outlet NOx sensor location can vary depending on engine application. It is usually located in the exhaust system at the outlet of the selective catalytic reduction (SCR) catalyst.

 

Conditions for Running the Diagnostics

This diagnostic runs when the aftertreatment SCR outlet temperature has been above 200°C [392° F] for a calibratable period of time while the engine is running.

Conditions for Setting the Fault Codes

The Engine Control Module (ECM) detected the power supply to the outlet NOx sensor was above or below a calibrated threshold.

Action Taken When the Fault Code is Active

  • The ECM illuminates the amber CHECK ENGINE lamp and/or malfunction indicator lamp (MIL) after the diagnostic fails on two consecutive trips.

Conditions for Clearing the Fault Code

  • To validate the repair, start and operate the engine to raise exhaust temperatures. This can be done by either driving the vehicle or initiating a stationary regeneration using the recommended Cummins® electronic service tool or equivalent.
  • The aftertreatment SCR outlet temperature must be above 200° C [392° F] for 60 seconds before the aftertreatment outlet NOx sensor can run its internal diagnostics.
  • 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 ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
  • 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 “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:

  • Short to battery or ground in the OEM wiring harness.

Open NOx sensor power supply circuit in the OEM harness

  • Incorrect system voltage set-up in the recommended Cummins® electronic service tool or equivalent.

Internal malfunction of the outlet NOx sensor

  • The NOx sensor part number is incorrect.
  • Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

For intermittent power supply and datalink communication issues with Aftertreatment Components, it is highly recommended that the OEM Power Distribution Center fuses and relays be thoroughly checked for loose, missing or intermittent connections.

Solution: S00000292

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.

Specification

Before troubleshooting this fault code, troubleshoot any fault code that is active or has more than one inactive count within the last 25 engine operating hours from the following list:

  • Voltage: 441, 442, 596, 597, 598, 6256

Linked Solutions

  • None

Repair

  • Perform a search on the appropriate fault codes.

Validation

  • None

Solution: S00011171

Verification

Conditions

  • Turn keyswitch OFF.

Action

  • Visually inspect the batteries and the battery cable connections for corrosion.
  • Measure the voltage from the positive (+) battery terminal to the negative (-) battery terminal.
  • If this vehicle has been repaired within the last 30 days for the same fault code, then proceed to the Linked Solutions section.

Specification

  • If the battery voltage is at least 10.8 VDC (12 volt systems) or 21.6 VDC (24 volt systems), then proceed to the Linked Solutions section.
  • If the battery voltage is below 10.8 VDC (12 volt systems) or 21.6 VDC (24 volt systems), then proceed to the Repair section.
  • If the battery or battery cables show signs of corrosion or damage, then proceed to the Repair Section.

Linked Solutions

  • Battery load test

Refer to S00001379

  • Ground inspection

Refer to S00000754

Repair

Repair or replace only the components that were found to be out of specification.

  • Charge or replace the batteries.

Refer to OEM Service Manual

  • Clean corrosion or tighten battery cable connections.

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.

Solution: S00001379

Verification

Conditions

  • Turn keyswitch OFF.

Action

  • Disconnect the batteries from each other.
  • Connect a load tester separately to each battery.
  • Measure the voltage from the positive (+) battery terminal to the negative (-) battery terminal.

Specification

  • For a 12 volt system, proceed to the Repair section if the battery voltage is below the following specification: 11 VDC
  • For a 24 volt system, proceed to the Repair section if the battery voltage is below the following specification: 22 VDC

Linked Solutions

  • None

Repair

  • Charge or replace the batteries.

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.

Solution: S00000754

Verification

Conditions

  • Turn keyswitch OFF.

Action

  • Visually inspect the ECM ground for damage, corrosion and loose connections.
  • Visually inspect the aftertreatment interface wiring harness ground for damage, corrosion and loose connections.
  • Visually inspect the OEM wiring harness ground for damage, corrosion and loose connections.
  • Visually inspect the grounds for proper routing.

Specification

  • If damage, corrosion or incorrect routing of grounds are found, then proceed to the Repair section

Linked Solutions

  • None

Repair

  • Clean or replace connections.

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.

Solution: S00000886

Verification

Conditions

  • Turn keyswitch ON.
  • Connect the recommended Cummins® electronic service tool or equivalent.

Action

  • Verify the Electrical System Voltage setting is correct for the engine configuration with the recommended Cummins® electronic service tool or equivalent.

Specification

  • If the Electrical System Voltage setting does not match the measured voltage, then the incorrect adjustable parameter is configured.

Linked Solutions

  • None

Repair

  • Use the recommended Cummins® electronic service tool or equivalent.
  • Configure the electrical system voltage to match the engine configuration.

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: S00011101

Verification

Conditions

  • Turn keyswitch OFF.
  • Disconnect the aftertreatment outlet NOx sensor from the aftertreatment interface wiring harness.

Action

  • Inspect the pins and connectors for damage.

Refer to Procedure 019-361

  • Turn keyswitch ON.
  • Measure the voltage between the aftertreatment outlet NOx sensor battery voltage SUPPLY pin and the aftertreatment outlet NOx sensor RETURN pin at the sensor connector of the aftertreatment interface wiring harness.
  • Refer to the circuit diagram or wiring diagram for connector pin identification.

Specification

  • Proceed to the Linked Solutions section if the voltage is not within the following specification of battery voltage: 1 VDC

Linked Solutions

  • Aftertreatment power relay voltage check

Refer to S00010303

  • Aftertreatment power relay resistance check

Refer to S00010305

  • Aftertreatment outlet NOx sensor circuit check

Refer to S00010333

  • Aftertreatment power relay circuit check

Refer to S00010368

Repair

  • No additional action is required for this solution.

Validation

  • None

Solution: S00010303

Verification

Conditions

  • Turn keyswitch OFF.
  • Disconnect the aftertreatment power relay from the OEM wiring harness.

Action

  • Inspect the pins and connectors for damage.

Refer to Procedure 019-361

  • Turn keyswitch ON.
  • Measure the voltage between the aftertreatment power relay battery voltage SUPPLY pin in the aftertreatment power relay connector of the OEM wiring harness and ground.
  • Refer to the circuit diagram or wiring diagram for connector pin identification.

Specification

  • A malfunctioning fuse or OEM wiring harness has been detected if the voltage is not within the following specification of battery voltage: 1 VDC

Linked Solutions

  • None

Repair

Repair or replace only the components that were found to be out of specification.

  • Replace the fuse.

Refer to Procedure 019-198

  • Repair or replace the OEM wiring harness.

Refer to Procedure 019-071

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: S00010305

Verification

Conditions

  • Turn keyswitch OFF.
  • Disconnect the aftertreatment power relay from the OEM wiring harness.

Action

  • Inspect the pins and connectors for damage.

Refer to Procedure 019-361

  • Check the relay.

Refer to Procedure 019-642

  • Refer to the circuit diagram or wiring diagram for connector pin identification.

Specification

  • If the relay does not meet specification, then a malfunctioning relay has been detected.

Linked Solutions

  • None

Repair

  • Replace the aftertreatment power relay.

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.

Solution: S00010333

Verification

Conditions

  • Turn keyswitch OFF.
  • Disconnect the aftertreatment power relay from the OEM wiring harness.
  • Disconnect the aftertreatment outlet NOx sensor from the aftertreatment interface wiring harness.

Action

  • Inspect the pins and connectors for damage.

Refer to Procedure 019-361

  • Measure the resistance between the aftertreatment power relay SUPPLY pin at the aftertreatment power relay connector of the OEM wiring harness and the aftertreatment power relay SUPPLY pin at the aftertreatment interface wiring harness aftertreatment outlet NOx sensor connector.
  • Refer to the circuit diagram or wiring diagram for connector pin identification.

Specification

  • A malfunctioning OEM wiring harness or aftertreatment interface wiring harness has been detected if the resistance is greater than the following specification: 10 Ω

Linked Solutions

  • None

Repair

Repair or replace only the components that were found to be out of specification.

  • Troubleshoot the OEM wiring harness, aftertreatment interface wiring harness, and all interconnects.
  • Repair or replace the OEM wiring harness.

Refer to Procedure 019-071

  • Repair or replace the aftertreatment interface wiring harness.

Refer to Procedure 019-477

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: S00010368

Verification

Conditions

  • Turn keyswitch OFF.
  • Disconnect the aftertreatment power relay from the OEM wiring harness.
  • Disconnect the engine wiring harness connector from the ECM.

Action

  • Inspect the pins and connectors for damage.

Refer to Procedure 019-361

  • Measure the resistance between the aftertreatment power relay CONTROL pin at the aftertreatment power relay connector of the OEM wiring harness and the aftertreatment power relay CONTROL pin at the engine wiring harness ECM connector.
  • Refer to the circuit diagram or wiring diagram for connector pin identification.

Specification

  • A malfunctioning OEM wiring harness or engine wiring harness has been detected if the resistance is greater than the following specification: 10 Ω

Linked Solutions

  • None

Repair

Repair or replace only the components that were found to be out of specification.

  • Troubleshoot the OEM wiring harness, engine wiring harness, and all interconnects.
  • Repair or replace the OEM wiring harness.

Refer to Procedure 019-071

  • Repair or replace the engine wiring harness.

Refer to Procedure 019-043

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: S00011099

Verification

Conditions

  • Turn keyswitch OFF.
  • Disconnect all components on the wiring circuit being tested.

Action

This test is NOT for checking the J1939 data link (+) and (-) pins since it may cause damage to the J1939 smart devices or sensors.

This test is NOT for checking the OEM wiring harness since it may cause damage to OEM smart devices or sensors.

  • Perform the Circuit Load Test for the circuit being tested.

Refer to Procedure 019-359

  • Refer to the circuit diagram or wiring diagram for connector pin identification.

Specification

  • If the voltage drop is not within specification, then a malfunctioning wiring harness has been detected.

Linked Solutions

  • None

Repair

Repair or replace only the components that were found to be out of specification.

  • Repair or replace the engine wiring harness.

Refer to Procedure 019-043

  • Repair or replace the OEM wiring harness.

Refer to Procedure 019-071

  • Repair or replace the aftertreatment interface wiring harness.

Refer to Procedure 019-477

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: S00000540

Verification

Conditions

  • Turn keyswitch OFF.

Action

  • Verify the correct aftertreatment outlet NOx sensor is installed for engine configuration (12 or 24 volt).

Specification

  • If the aftertreatment outlet NOx sensor is not the correct sensor part number for the engine configuration, then the incorrect sensor has been installed.

Linked Solutions

  • None

Repair

  • Replace the aftertreatment outlet NOx sensor.

Refer to Procedure 019-451

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.

Refer to Procedure 019-032

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.

If all steps have been completed and no root cause has been identified, then follow the technical escalation process.

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