verview
| CODE | REASON | EFFECT |
| Fault Code: 7381 PID: SPN: 4374 FMI: 2/20 LAMP: Amber SRT: |
The aftertreatment diesel exhaust fluid dosing unit is running erratically.
|
Diesel exhaust fluid injection into the SCR aftertreatment system is disabled. |
Circuit Description
The aftertreatment diesel exhaust fluid dosing unit performs many functions, one of which is to generate adequate diesel exhaust fluid pressure in the lines, using a pump, to allow for dosing. The ECM provides a battery voltage supply and a ground to the diesel exhaust fluid dosing unit. The ECM also supplies a signal to the dosing unit to control the diesel exhaust fluid output. This signal changes, based on the diesel exhaust fluid pressure being commanded.
Component Location
The aftertreatment diesel exhaust fluid dosing unit location is original equipment manufacturer (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) detected an erratic value from the aftertreatment diesel exhaust fluid dosing unit.
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.
- Diesel exhaust fluid injection into the aftertreatment system is disabled.
Conditions for Clearing the Fault Code
- To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
- 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:
- Malfunctioning or damaged fuse.
- Malfunctioning or damaged OEM wiring harness.
- Malfunctioning or damaged aftertreatment diesel exhaust fluid dosing unit.
Troubleshooting Summary
- Check for primary fault codes
- Aftertreatment diesel exhaust fluid dosing unit relay voltage check
- Aftertreatment diesel exhaust fluid dosing unit pump motor open circuit check
- Aftertreatment diesel exhaust fluid dosing unit pump motor circuit pin to ground short
- Aftertreatment diesel exhaust fluid dosing unit pump motor circuit pin to pin short
- Aftertreatment diesel exhaust fluid dosing unit is malfunctioning
Solution: S00008351
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 diesel exhaust fluid system: 1682, 3565, 3567, 3568, 3571, 3572, 3574, 3575, 3596, 4658, 5865, 5936, 6485, 6486
Linked Solutions
- None
Repair
- Perform a search on the appropriate fault codes.
Validation
- None
Solution: S00001015
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit relay from the OEM wiring harness.
Action
- Inspect the pins and connectors for damage.
- Turn keyswitch ON.
- Measure the voltage between the aftertreatment diesel exhaust fluid dosing unit relay battery SUPPLY pin at the relay OEM wiring harness connector and ground.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- A malfunctioning fuse, OEM wiring harness or aftertreatment 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 OEM Service Manual
- Repair or replace the OEM wiring harness.
Validation
- 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.
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- 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.
Solution: S00007413
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the OEM wiring harness.
- Disconnect the engine wiring harness connector from the ECM.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid pump motor speed SIGNAL pin at the aftertreatment diesel exhaust fluid dosing unit OEM wiring harness connector and the aftertreatment diesel exhaust fluid pump motor speed SIGNAL 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 engine wiring harness.
- Repair or replace the OEM wiring harness.
Validation
- 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.
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- 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.
Solution: S00007414
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the OEM wiring harness.
- Disconnect the engine wiring harness connector from the ECM.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid pump motor speed SIGNAL pin at the engine wiring harness ECM connector and ground.
- 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 less than the following specification: 100k 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 engine wiring harness.
- Repair or replace the OEM wiring harness.
Validation
- 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.
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- 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.
Solution: S00007415
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the OEM wiring harness.
- Disconnect the engine wiring harness connector from the ECM.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid pump motor speed SIGNAL pin at the engine wiring harness ECM connector and all other pins in that 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 less than the following specification: 100k 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 engine wiring harness.
- Repair or replace the OEM wiring harness.
Validation
- 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.
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- 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.
Solution: S00000677
Verification
Conditions
- Connect the aftertreatment diesel exhaust fluid dosing unit to the OEM wiring harness.
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 Diesel Exhaust Fluid System Leak Test found under ECM Diagnostic Tests.
Specification
- If the fault code is still active after the Aftertreatment Diesel Exhaust Fluid System Leak Test is completed, then a malfunctioning aftertreatment diesel exhaust fluid dosing unit has been detected.
Linked Solutions
- None
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.