Cummins X12 CM2350 Fault Code 1694 | SPN 3226 | FMI 2/2

Uncategorized

Aftertreatment 1 Outlet NOx Sensor – Data Erratic, Intermittent, or Incorrect

 

Overview

 

CODE REASON EFFECT
Fault Code: 1694
PID: 
SPN: 3226
FMI: 2/2
LAMP: Amber
SRT: 

 

An incorrect NOx sensor reading has been detected by the aftertreatment outlet NOx sensor.

 

 

Possible reduced engine performance.

 
Aftertreatment Outlet NOx Sensor Circuit

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 has to meet specific engine and aftertreatment conditions to run and complete.

Conditions for Setting the Fault Codes

The Engine Control Module (ECM) detected the aftertreatment outlet NOx sensor reading was not changing with engine conditions or is stuck.

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.
  • To validate the repair using a Chassis Dynamometer, utilize a routine that incorporates acceleration and motoring events, steady state highway type operation, and load. This will simulate normal driving and allow the diagnostics in the ECM to run.
  • To validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stop and go city type driving and steady state highway type driving. It may be necessary to load the unit for certain diagnostics in the ECM to run.
  • 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:

Diesel exhaust fluid crystallization or deposits

Incorrectly installed aftertreatment outlet NOx sensor

Malfunctioning aftertreatment outlet NOx sensor

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM

This diagnostic will NOT run during a regeneration.

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.

Troubleshooting Summary

  1. Check for primary fault codes
  2. Aftertreatment exhaust system leaks
  3. Aftertreatment outlet NOx sensor check
  4. Deposits in the SCR decomposition tube
  5. Leaks in the aftertreatment diesel exhaust fluid dosing system
  6. Aftertreatment Diesel Exhaust Fluid Doser Pump Override test
  7. Aftertreatment diesel exhaust fluid dosing valve is malfunctioning
  8. Aftertreatment SCR System Test
  9. Aftertreatment diesel exhaust fluid dosing system test failed
  10. Aftertreatment intake NOx sensor failed
  11. Aftertreatment outlet NOx sensor – Inspection
  12. Inspect both aftertreatment NOx sensors
  13. Aftertreatment SCR Catalyst Test Failed
  14. Aftertreatment outlet NOx sensor is malfunctioning

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:

  • Aftertreatment NOx: 1885, 1887, 2771, 3228, 3232, 3545, 3583, 3649, 3681, 3682, 3725, 3748, 3749

Linked Solutions

  • None

Repair

  • Perform a search on the appropriate fault codes.

Validation

  • None

Verification

Conditions

  • Engine running.

Action

  • Visually inspect for leaks in the exhaust manifold to head.
  • Visually inspect for leaks from the turbocharger to exhaust manifold.
  • Visually inspect for leaks in the exhaust plumbing between the turbocharger outlet and the Aftertreatment DOC intake connection.
  • Visually inspect the exhaust piping for leaks, cracks, and loose connections.
  • Inspect for leaks at the aftertreatment DOC housing, sensor ports and connection points.
  • Visually inspect the aftertreatment and SCR components for exhaust leaks.

Specification

  • If there is any damage or leaks found in the exhaust system, then proceed to the Repair section.

Linked Solutions

  • None

Repair

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

  • Replace the exhaust manifold.
  • Repair or replace the exhaust plumbing.

Refer to OEM Service Manual

  • Replace aftertreatment DOC.
  • Replace the aftertreatment diesel particulate filter.
  • Replace the aftertreatment SCR Catalyst.

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.

3 – Aftertreatment outlet NOx sensor check

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.

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.

Verification

Conditions

  • Turn keyswitch OFF.

Action

  • Inspect the decomposition tube for deposits.

Specification

  • If any excessive aftertreatment diesel exhaust fluid deposits were found inside the decomposition tube, then a plugged or restricted aftertreatment decomposition tube has been detected.
  • Proceed to Linked Solutions section for additional checks.

Linked Solutions

  • Leaks in the aftertreatment diesel exhaust fluid dosing system

Repair

  • Clean and install the decomposition tube.

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.

Verification

Conditions

  • Turn keyswitch OFF.
  • Reconnect all aftertreatment diesel exhaust fluid lines and electrical connectors to the dosing unit and aftertreatment diesel exhaust fluid tank if they have been previously disconnected during troubleshooting.

Action

  • Remove the aftertreatment diesel exhaust fluid dosing valve.
  • Perform the Aftertreatment Diesel Exhaust Fluid System Leak Test found under ECM Diagnostic Tests.

Specification

  • If a line, fitting, connection, or dosing unit is leaking, then a malfunction has been detected in the aftertreatment diesel exhaust fluid system or dosing unit.

Linked Solutions

  • None

Repair

  • Repair or replace the leaking components.

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.

Verification

Conditions

  • Reconnect all aftertreatment diesel exhaust fluid lines and electrical connectors to the dosing unit and aftertreatment diesel exhaust fluid tank if they have been previously disconnected during troubleshooting.

Action

  • Remove the aftertreatment diesel exhaust fluid dosing valve from the decomposition tube.
  • Turn keyswitch ON.
  • Connect the recommended Cummins® electronic service tool or equivalent.
  • Use the recommended Cummins electronic service tool or equivalent.
  • Perform the Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test.

The Aftertreatment Diesel Exhaust Fluid Doser Pump Override test can only be ran twice before a key cycle needs to be performed.

Specification

  • If the Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test meets the specification, then proceed to the next solution.
  • If the Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test does not meet the specification, then proceed to the Linked Solutions section.

Linked Solutions

Click on the link below:

  • Aftertreatment diesel exhaust fluid dosing valve is malfunctioning

Repair

  • No additional action is required for this solution.

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.

Verification

Conditions

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

Action

  • Clean the aftertreatment diesel exhaust fluid dosing valve.
  • Turn keyswitch ON.
  • Use the recommended Cummins electronic service tool or equivalent.
  • Perform the Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test.

Specification

  • If the Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test is not within specification, then proceed to the Repair section.

Linked Solutions

  • None

Repair

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

  • Replace the aftertreatment diesel exhaust fluid dosing valve.
  • Replace aftertreatment diesel exhaust fluid dosing unit.

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.

Verification

Conditions

  • Connect all components.

Action

  • Turn keyswitch ON.
  • Connect the recommended Cummins electronic service tool or equivalent.
  • Use the recommended Cummins electronic service tool or equivalent.
  • Perform the Aftertreatment SCR System Test.

If the Aftertreatment SCR System Test is not available on the recommended Cummins electronic service tool or equivalent, update to the latest ECM Calibration Revision and then perform the Aftertreatment SCR System Test.

Specification

  • If the Aftertreatment SCR System Test does not pass, then proceed to the Linked Solutions section.

If the Aftertreatment SCR System Test does not activate, then reset the Search to Aftertreatment SCR System Test does not activate.

If the Aftertreatment SCR System Test does not complete, then reset the Search to Aftertreatment SCR System Test does not complete.

If the Aftertreatment SCR System Test displays “Deposit Burn Failed”, the test should keep running and no repair action is required unless a Aftertreatment Intake or Outlet NOx sensor failure is detected.

Linked Solutions

  • Aftertreatment diesel exhaust fluid dosing system test failed
  • Aftertreatment intake NOx sensor failed
  • Aftertreatment outlet NOx sensor – Inspection
  • Inspect both aftertreatment NOx sensors
  • Aftertreatment SCR catalyst test failed

Repair

  • No additional action is required for this solution.

Validation

  • None

Verification

Conditions

  • Turn keyswitch OFF.

Action

  • Inspect the aftertreatment diesel exhaust fluid in the tank for signs of debris or contamination.
  • Perform the Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test.

Specification

  • If there are signs of contaminates in the diesel exhaust fluid, then proceed to the Repair section.
  • If the Aftertreatment Diesel Exhaust Fluid Doser Pump override test displays FAILED, then proceed to the Repair section.

Linked Solutions

  • None

Repair

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

  • Drain the diesel exhaust fluid tank, clean thoroughly and refill with pure diesel exhaust fluid.

Refer to OEM Service Manual

  • For a Aftertreatment Diesel Exhaust Fluid Doser Pump override test displaying FAILED, then follow the repair instructions in the procedure.

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.

Verification

Conditions

  • None

Action

  • Verify that the aftertreatment intake NOx sensor is displayed as FAILED.

Specification

  • If the SCR System test displays that the intake NOx sensor has FAILED, then proceed to the Repair section.

Linked Solutions

  • None

Repair

  • Replace the aftertreatment intake NOx sensor.

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.

Verification

Conditions

  • Turn keyswitch OFF.

Action

  • Inspect the decomposition tube for deposits.
  • Visually inspect the aftertreatment diesel exhaust fluid tank connections for cracks or pitting.

Refer to OEM Service Manual

  • Connect all aftertreatment diesel exhaust fluid lines and electrical connectors to the dosing unit and aftertreatment diesel exhaust fluid tank.
  • Remove the aftertreatment diesel exhaust fluid dosing valve from the decomposition tube.
  • Turn keyswitch ON.
  • Connect the recommended Cummins electronic service tool or equivalent.
  • Perform the Aftertreatment Diesel Exhaust Fluid System Leak Test found under ECM Diagnostic Tests.
  • While the test is running, inspect the diesel exhaust fluid tank connectors, diesel exhaust fluid dosing unit and dosing unit connectors, diesel exhaust fluid lines, and diesel exhaust fluid dosing valve for signs of external leaks.

Specification

  • If the aftertreatment diesel exhaust fluid dosing valve is not leaking and there are no deposits in the decomposition tube, then a malfunctioning aftertreatment outlet NOx sensor has been detected.

Linked Solutions

  • None

Repair

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

  • Replace the aftertreatment outlet NOx sensor.
  • Replace the aftertreatment diesel exhaust fluid dosing valve.
  • Clean and install the decomposition tube.

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.

Verification

Conditions

  • Turn keyswitch OFF.

Action

  • Inspect the decomposition tube for deposits.
  • Inspect the aftertreatment diesel exhaust fluid tank connections for cracks or pitting.

Refer to OEM Service Manual

  • Connect all aftertreatment diesel exhaust fluid lines and electrical connectors to the dosing unit and aftertreatment diesel exhaust fluid tank.
  • Remove the aftertreatment diesel exhaust fluid dosing valve from the decomposition tube.
  • Turn keyswitch ON.
  • Connect the recommended Cummins electronic service tool or equivalent.
  • Perform the Aftertreatment Diesel Exhaust Fluid System Leak Test found under ECM Diagnostic Tests.
  • Verify proper sealing at all connection points, including diesel exhaust fluid tank, dosing unit, and dosing valve.

Specification

  • If the aftertreatment diesel exhaust fluid dosing valve is not leaking and there are no deposits in the decomposition tube, then a malfunctioning aftertreatment intake NOx sensor and a malfunctioning aftertreatment outlet NOx sensor has been detected.

Linked Solutions

  • None

Repair

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

  • Replace the aftertreatment intake NOx sensor.
  • Replace the aftertreatment outlet NOx sensor.
  • Replace the aftertreatment diesel exhaust fluid dosing valve.
  • Clean and install the decomposition tube.

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.

Verification

Conditions

  • Reconnect all aftertreatment diesel exhaust fluid lines and electrical connectors to the dosing unit and aftertreatment diesel exhaust fluid tank if they have been previously disconnected during troubleshooting.

Action

The aftertreatment diesel exhaust fluid dosing valve must be removed and placed in a measuring container greater then 1.5 liter [50 oz] capacity to perform the Aftertreatment Diesel Exhaust Fluid Doser Pump Override test.

The Aftertreatment Diesel Exhaust Fluid Doser Pump Override test can only be ran twice before a key cycle needs to be performed.

  • Remove the aftertreatment diesel exhaust fluid dosing valve from the decomposition tube.
  • Turn keyswitch ON.
  • Connect the recommended Cummins electronic service tool or equivalent.
  • Perform the Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test.

Specification

  • If the Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test is not within specification, then proceed to the Repair section.
  • If the Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test is within specification, then a malfunctioning aftertreatment SCR Catalyst has been detected.

Linked Solutions

  • None

Repair

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

  • Replace the aftertreatment diesel exhaust fluid dosing valve.
  • Replace the aftertreatment SCR Catalyst.

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.

Verification

Conditions

  • None

Action

  • 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 one count within the last 25 engine hours and all the preceding solution verifications have been performed, then a malfunctioning aftertreatment outlet NOx sensor has been detected.

Linked Solutions

  • None

Repair

  • Replace the aftertreatment outlet NOx sensor.

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.