Overview
| CODE | REASON | EFFECT |
| Fault Code: 5935 PID: SPN: 4334 FMI: 7/7 LAMP: Amber SRT: |
The Diesel Exhaust pressure sensor is reading erratic.
|
Possible reduced engine performance. |
Circuit Description
The aftertreatment diesel exhaust fluid dosing valve is controlled by the ECM. When the engine control module (ECM) commands DEF dosing, the ECM sends a pulse width modulated (PWM) signal to the dosing valve, which opens the dosing valve and allows DEF to be sprayed into the exhaust stream.
Component Location
The aftertreatment diesel exhaust fluid dosing valve is installed in the exhaust system. It is mounted directly to the aftertreatment decomposition tube, before the selective catalytic reduction (SCR) catalyst. Installation position will vary, based on the aftertreatment architecture and the original equipment manufacturer (OEM).
Conditions for Running the Diagnostics
This diagnostic runs when the diesel exhaust fluid dosing valve is being commanded on.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the aftertreatment diesel exhaust fluid dosing valve is mechanically stuck.
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.
Conditions for Clearing the Fault Code
- It may be necessary to perform both validations to clear this fault:
- To validate the repair, perform the “Aftertreatment Diesel Exhaust Fluid Doser Pump Override Test” found under “ECM Diagnostic Tests” in the recommended Cummins® electronic service tool or equivalent.
- To validate the repair, key OFF for 1 minute, then key ON 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.
- The “Reset All Faults” command in the recommended Cummins® electronic service tool or equivalent can be used to clear active and inactive faults.
Shop Talk
Possible causes of this fault code include:
A malfunctioning aftertreatment diesel exhaust fluid dosing valve
Blocked, restricted, or frozen diesel exhaust fluid dosing valve return line or return line connector.
Troubleshooting Summary
Solution: S00000435
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: 3422, 3423, 3562, 3563, 3575
Linked Solutions
- None
Repair
- Perform a search on the appropriate fault codes.
Validation
- None
Solution: S00001042
Verification
Conditions
- Turn keyswitch OFF.
Action
- Visually inspect the dosing unit supply line, between the tank and the dosing unit (suction line) for signs of leaks and white deposits.
- Visually inspect the dosing valve supply line, between the dosing unit and the dosing valve (pressure line) for signs of leaks and white deposits.
- Visually inspect the return line, between the dosing valve and the tank (return line) for signs of leaks and white deposits.
- Visually inspect the return line and associated fittings/connectors for damage, signs of leaks or white deposits.
- Visually inspect the return line for any kinks or improper routing.
- Disconnect the return line dosing valve connectors and look for signs of buildup or blockage.
Specification
- If leaks, white deposits, damage or improper routing are found, then proceed to the Repair section.
Linked Solutions
- None
Repair
Repair or replace only the components that were found to be out of specification.
- Repair or replace damaged connections.
Refer to OEM Service Manual
- Repair or replace the leaking components.
Refer to OEM Service Manual
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: 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.
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.