Overview
| CODE | REASON | EFFECT |
| Fault Code: 4157 PID: SPN: 4376 FMI: 7/7 LAMP: Amber SRT: |
A stuck aftertreatment diesel exhaust fluid return valve has been detected.
|
Diesel exhaust fluid injection into the SCR aftertreatment system is disabled. |
Circuit Description
The aftertreatment diesel exhaust fluid dosing unit precisely measures the amount of aftertreatment diesel exhaust fluid to be injected into the aftertreatment system. The aftertreatment diesel exhaust fluid dosing unit has three primary cycles. A priming cycle makes sure that aftertreatment diesel exhaust fluid is available at the aftertreatment diesel exhaust fluid dosing unit. During the dosing cycle, aftertreatment diesel exhaust fluid is being delivered to the aftertreatment dosing valve. A purge cycle occurs when the engine is turned OFF. The purge cycle makes sure that all the aftertreatment diesel exhaust fluid is removed from the diesel exhaust fluid lines and dosing valve.
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.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the aftertreatment diesel exhaust fluid pressure did not drop when the aftertreatment diesel exhaust fluid return valve was commanded on.
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.
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, perform the «Aftertreatment Diesel Exhaust Fluid System Leak Test» found under «ECM Diagnostic Tests» in the recommended Cummins® electronic service tool or equivalent.
- 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:
A malfunctioning aftertreatment diesel exhaust fluid return valve
Blocked, restricted, kinked, broken, disconnected or frozen diesel exhaust fluid supply lines
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.
For intermittent power supply and data link 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
Solution: S00000664
Verification
Conditions
- Turn keyswitch OFF.
Action
- Verify the lines are not swapped at the dosing unit, dosing valve or diesel exhaust fluid tank connections.
- Visually inspect the aftertreatment diesel exhaust fluid tank connections for cracks or pitting.
- Visually inspect the aftertreatment diesel exhaust fluid tank vent line for restrictions.
- Visually inspect the aftertreatment diesel exhaust fluid line for damage.
- Visually inspect both dosing unit connections and fittings for loose, leaking, or damaged connections.
- Disconnect the suction line and pressure line dosing unit connectors and look for signs of build-up or blockage.
- Inspect the aftertreatment diesel exhaust fluid dosing unit inlet connector screen.
- Visually inspect the suction line for signs of leakage or openings which will allow the dosing unit to suck in air with the diesel exhaust fluid.
- Visually inspect the pressure line for signs of leakage or rupture.
- Verify proper sealing at all connection points, including diesel exhaust fluid tank, dosing unit, and dosing valve.
Specification
- If there are aftertreament diesel exhaust fluid lines reversed, damaged, leaking or restricted connections found, then proceed to the Repair section.
Linked Solutions
- None
Repair
- Repair or replace damaged components.
Refer to OEM Service Manual
- Replace the aftertreatment diesel exhaust fluid dosing unit inlet connector screen.
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: S00003113
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the OEM wiring harness.
- Disconnect the aftertreatment diesel exhaust fluid controller from the OEM wiring harness.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid return valve SUPPLY pin at the aftertreatment diesel exhaust fluid dosing unit harness connector and the aftertreatment diesel exhaust fluid return valve SUPPLY pin of the aftertreatment diesel exhaust fluid controller harness connector.
- Measure the resistance between the aftertreatment diesel exhaust fluid return valve SIGNAL pin at the aftertreatment diesel exhaust fluid dosing unit harness connector and the aftertreatment diesel exhaust fluid return valve SIGNAL pin of the aftertreatment diesel exhaust fluid controller harness connector.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- A malfunctioning OEM wiring harness has been detected if the resistance is greater than the following specification: 10 Ω
- Proceed to the next Linked Solution if the resistance is greater than the following specification: 10 Ω
Linked Solutions
Click on the link below:
- Aftertreatment diesel exhaust fluid dosing unit open circuit check
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: S00003114
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the OEM wiring harness.
- Disconnect the aftertreatment diesel exhaust fluid controller from the OEM wiring harness.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid return valve SUPPLY pin at the aftertreatment diesel exhaust fluid dosing unit connector and the aftertreatment diesel exhaust fluid return valve SIGNAL pin at the aftertreatment diesel exhaust fluid dosing unit connector.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- If the resistance is not within specification, then a malfunctioning afertreatment 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.
Solution: S00000730
Verification
Conditions
- Turn keyswitch ON.
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
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.