Aftertreatment Fuel Shutoff Valve – Data Erratic, Intermittent, or Incorrect
Overview
| CODE | REASON | EFFECT |
| Fault Code: 1925 PID: S334 SPN: 3482 FMI: 2/2 LAMP: Amber SRT: |
An error has been detected in the aftertreatment fuel shutoff valve or the aftertreatment fuel injector system.
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Possible reduced engine performance.
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Aftertreatment Fuel Injection System
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Circuit Description
Before active regeneration of the aftertreatment diesel particulate filter, a diagnostic test on the system is performed. The aftertreatment fuel injector opens and relieves fuel pressure in the line. The aftertreatment fuel pressure sensor must be reading atmospheric pressure at this point in the test. The aftertreatment fuel injector closes and the aftertreatment purge air actuator opens. This pressurizes the aftertreatment fuel system to vehicle air pressure. The diagnostic then checks to make sure the aftertreatment fuel pressure sensor is reading vehicle air pressure. The aftertreatment fuel shutoff valve then opens and allows pressurized fuel to enter the system. The aftertreatment fuel injector then opens and primes the system by purging the air from the line. The aftertreatment fuel shutoff valve and aftertreatment fuel injector then close and trap the fuel between the aftertreatment fuel shutoff valve and the aftertreatment fuel injector. The diagnostic checks to make sure the system maintains fuel pressure.
Component Location
The aftertreatment fuel injector is installed in the exhaust system in the turbocharger adapter pipe. The aftertreatment fuel pressure sensor and aftertreatment fuel shutoff valve are installed in the shutoff valve manifold. The aftertreatment purge air actuator is located above the shutoff valve manifold.
Conditions for Running the Diagnostics
This diagnostic runs during active regeneration of the aftertreatment diesel particulate filter.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected an internally leaking aftertreatment fuel shutoff valve, aftertreatment purge air actuator, or a stuck closed aftertreatment fuel injector.
Action Taken When the Fault Code is Active
- The ECM illuminates the amber CHECK ENGINE lamp and/or the malfunction indicator lamp (MIL) immediately when the diagnostic runs and fails.
Active regeneration of the aftertreatment diesel particulate filter will be disabled unitl the next key cycle.
Engine torque will be 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 perform the recommended Cummins electronic service tool or equivalent Aftertreatment Diesel Particulate Filter Regeneration Test.
- 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.
Possible causes of this fault code include:
Internal leak of the aftertreatment fuel shutoff valve allowing fuel pressure to leak past the shutoff valve
Internal leak of the aftertreatment purge air actuator
Stuck closed, plugged, or clogged aftertreatment fuel injector.
Troubleshooting Summary
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 fuel: 1926, 1927, 1928
- Fuel: 2215
Linked Solutions
- None
Repair
- Perform a search on the appropriate fault codes.
Validation
- None
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment fuel supply line from the aftertreatment fuel injector.
- Disconnect the air supply line from the aftertreatment fuel shutoff manifold.
- Connect the fuel extension line.
- Place the end of the line in an empty fuel container.
- Turn keyswitch ON.
- Connect the recommended Cummins electronic service tool or equivalent.
Action
- Use the recommended Cummins electronic service tool or equivalent.
- Monitor the aftertreatment fuel pressure.
Specification
- A malfunctioning aftertreatment fuel pressure sensor has been detected If the recommended Cummins electronic service tool or equivalent reading are not within the following specification: 0 +/- 77 mm-Hg [3 in-hg], 0 +/- 10 kPa [1.5 psi]
Linked Solutions
- None
Repair
- Replace aftertreatment fuel pressure 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
- Perform the Aftertreatment Fuel Injector Flow Test.
Specification
- If the Aftertreatment Fuel Injector Flow Test does not meet specification, then a malfunctioning aftertreatment fuel injector has been detected.
Linked Solutions
- None
Repair
- Clean or replace the aftertreatment fuel injector.
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
- Disconnect the aftertreatment fuel supply line from the aftertreatment fuel injector.
- Connect the fuel extension line.
- Turn keyswitch ON.
- Engine running at idle.
Action
- Check for a stuck open or leaking aftertreatment fuel shutoff valve.
- Check for a leaking aftertreatment fuel injector supply line extension.
Specification
- If fuel is leaking from the aftertreatment fuel shutoff valve or aftertreatment fuel injector supply line extension, then a malfunctioning aftertreatment fuel shutoff valve has been detected.
Linked Solutions
- None
Repair
- Replace aftertreatment fuel shutoff valve.
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
- Disconnect the aftertreatment fuel supply line from the aftertreatment fuel injector.
- Connect the fuel extension line.
- Place the end of the line in an empty fuel container.
- Turn keyswitch ON.
- Connect the recommended Cummins electronic service tool or equivalent.
- Engine running at idle.
Action
- Check for a stuck open or leaking aftertreatment purge air actuator.
- Check for air flowing from the supply line.
Specification
- If any air is flowing from the supply line, then a malfunctioning aftertreatment purge air actuator has been detected.
Linked Solutions
- None
Repair
- Replace aftertreatment purge air actuator.
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.