Overview
| CODE | REASON | EFFECT |
| Fault Code: 5936 PID: SPN: 4334 FMI: 0/15 LAMP: Amber SRT: |
The Diesel Exhaust Fluid Pressure did not decrease below a threshold after a key off.
|
Possible reduced engine performance. |
Circuit Description
The diesel exhaust fluid dosing unit lines are responsible for transporting diesel exhaust fluid between the dosing unit, dosing valve, and diesel exhaust fluid tank.
Component Location
There are three diesel exhaust fluid lines. One line is between the dosing unit and dosing valve, and the other two lines are between the dosing unit and the diesel exhaust fluid tank. These lines can be partially hidden from view by the SCR system and other vehicle components. Line routing will vary, based on the aftertreatment architecture and the OEM.
Conditions for Running the Diagnostics
This diagnostic runs immediately after the keyswitch is turned OFF.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the aftertreatment diesel exhaust fluid pressure was greater than a threshold.
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.
- Engine torque may be reduced.
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 System Leak 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:
- The line heaters are not successfully thawing the frozen diesel exhaust fluid
The diesel exhaust fluid return line between the diesel exhaust fluid tank and the dosing valve is kinked or blocked
Troubleshooting Summary
- Check for primary fault codes
- Plugged or restricted aftertreatment diesel exhaust dosing valve return line or fittings
- 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
- ECM calibration revision history check
Solution: S00000434
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 temperature: 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: 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: S00001013
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the OEM wiring harness.
- Disconnect the OEM 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 control SIGNAL pin at the aftertreatment diesel exhaust fluid dosing unit OEM wiring harness connector and the aftertreatment diesel exhaust fluid pump motor control SIGNAL pin at the OEM wiring harness ECM 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
Linked Solutions
- None
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: S00001016
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the OEM wiring harness.
- Disconnect the OEM wiring harness connector from the ECM.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid dosing unit pump motor control SIGNAL pin of the dosing unit OEM wiring harness connector and engine block.
- 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 less than the following specification: 100k Ω
Linked Solutions
- None
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: S00001014
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the OEM wiring harness.
- Disconnect the OEM wiring harness connector from the ECM.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid dosing unit pump motor control SIGNAL pin at the OEM 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 has been detected if the resistance is less than the following specification: 100k Ω
Linked Solutions
- None
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.