Overview
| CODE | REASON | EFFECT |
| Fault Code: 3679 PID: SPN: 3361 FMI: 11/11 LAMP: Amber SRT: |
The diesel exhaust fluid dosing unit has failed to initialize.
|
Possible reduced engine performance. |
Circuit Description
The diesel exhaust fluid dosing unit monitors its internal temperature and reports it back to the diesel exhaust fluid controller at initial key ON via the aftertreatment diesel exhaust fluid dosing unit signal/dosing unit temperature wire. After the temperature message has been sent from the dosing unit to the controller, this shared wire is switched over to be used for dosing unit pump control.
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 at initial key ON.
Conditions for Setting the Fault Codes
The diesel exhaust fluid dosing unit and the diesel exhaust fluid controller were not able to acknowledge each other at key ON, and cannot initialize.
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.
- 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 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:
Short or open circuit in the aftertreatment wiring harness
Malfunctioning diesel exhaust fluid dosing unit.
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.
For intermittent power supply and datalink 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: S00002693
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 dosing unit: 3558, 3559, 3561
Linked Solutions
- None
Repair
- Perform a search on the appropriate fault codes.
Validation
- None
Solution: S00002928
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the OEM wiring harness.
Action
- Inspect the pins and connectors for damage.
- Inspect all connections for corrosion or loose connections.
Specification
- If the aftertreatment diesel exhaust fluid dosing unit connector or the aftertreatment diesel exhaust fluid dosing unit wiring harness connector show signs of diesel exhaust fluid, then a malfunctioning aftertreatment diesel exhaust fluid dosing unit connector has been detected.
Linked Solutions
- None
Repair
Repair or replace only the components that were found to be out of specification.
- Replace aftertreatment diesel exhaust fluid dosing unit.
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: S00003256
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid controller harness 86-pin connector from the aftertreatment diesel exhaust fluid controller.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the aftertreatment diesel exhaust fluid controller harness.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid dosing unit SUPPLY pin at the aftertreatment diesel exhaust fluid dosing unit harness connector and the aftertreatment diesel exhaust fluid dosing unit SUPPLY pin of the aftertreatment diesel exhaust fluid controller harness 86-pin connector.
- Measure the resistance between the aftertreatment diesel exhaust fluid dosing unit RETURN pin at the aftertreatment diesel exhaust fluid dosing unit harness connector and the aftertreatment diesel exhaust fluid dosing unit RETURN pin of the aftertreatment diesel exhaust fluid controller harness 86-pin connector.
- Measure the resistance between the aftertreatment diesel exhaust fluid dosing unit SIGNAL pin at the aftertreatment diesel exhaust fluid dosing unit harness connector and the aftertreatment diesel exhaust fluid dosing unit SIGNAL pin of the aftertreatment diesel exhaust fluid controller harness 86-pin connector.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- A malfunctioning aftertreatment diesel exhaust fluid controller harness has been detected if the resistance is greater than the following specification: 10
Linked Solutions
- None
Repair
- Repair or replace aftertreatment diesel exhaust fluid controller harness.
Refer to OEM Service Manual
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: S00003186
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid controller harness 86-pin connector from the aftertreatment diesel exhaust fluid controller.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the aftertreatment diesel exhaust fluid controller harness.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid dosing valve SIGNAL pin at the aftertreatment diesel exhaust fluid controller wiring harness 86-pin connector and ground.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- If the resistance is less than 100k Ω, then a malfunctioning aftertreatment diesel exhaust fluid controller harness has been detected.
Linked Solutions
- None
Repair
- Repair or replace aftertreatment diesel exhaust fluid controller harness.
Refer to OEM Service Manual
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: 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.