Overview
| CODE | REASON | EFFECT |
| Fault Code: 2976 PID: SPN: 3361 FMI: 2/2 LAMP: Amber SRT: |
An internal error has been detected in the aftertreatment diesel exhaust fluid dosing unit.
|
Possible reduced engine performance. |
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 immediately after the keyswitch is turned to the ON position, and continues until the diesel exhaust fluid dosing unit attempts to prime.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the aftertreatment diesel exhaust fluid dosing unit internal temperature was not communicated to the ECM by the diesel exhaust 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.
Engine torque will be reduced if the engine is operated for an extended period of time with this fault active.
Vehicle speed will be limited to 8 km [5 mi] per hour after extended engine operation with the fault code active.
Conditions for Clearing the Fault Code
- Start the engine and let it idle. If, after the engine idles for 10 minutes, the fault code is still not active, the repair has been validated.
- 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 dosing unit
Short circuit to ground in the aftertreatment diesel exhaust fluid dosing unit signal/dosing unit temperature wire.
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.
Troubleshooting Summary
- Aftertreatment diesel exhaust fluid dosing unit connector is malfunctioning
- Aftertreatment diesel exhaust fluid dosing unit harness open circuit check
- Aftertreatment diesel exhaust fluid dosing unit circuit pin to pin short
- Aftertreatment diesel exhaust fluid controller software phase check
- ECM calibration revision history check
- Aftertreatment diesel exhaust fluid controller is malfunctioning
- Aftertreatment diesel exhaust fluid dosing unit is malfunctioning
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: S00002994
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the aftertreatment diesel exhaust fluid controller wiring harness.
- Disconnect the aftertreatment diesel exhaust fluid controller wiring harness 86-pin connector from the aftertreatment diesel exhaust fluid controller.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid dosing unit temperature SIGNAL pin at the aftertreatment diesel exhaust fluid dosing unit wiring harness connector and the aftertreatment diesel exhaust fluid dosing unit temperature SIGNAL pin of the aftertreatment diesel exhaust fluid controller wiring 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 wiring harness connector and the aftertreatment diesel exhaust fluid dosing unit RETURN pin of the aftertreatment diesel exhaust fluid controller wiring harness 86-pin 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
- 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: S00003255
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid dosing unit from the aftertreatment diesel exhaust fluid controller harness.
- Disconnect the aftertreatment diesel exhaust fluid controller harness 86-pin connector from the aftertreatment diesel exhaust fluid controller.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid dosing unit SIGNAL pin at the aftertreatment diesel exhaust fluid controller wiring harness 86-pin connector and all other pins in the connector.
- 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: S00003120
Verification
Conditions
- Turn keyswitch ON.
- Connect the recommended Cummins® electronic service tool or equivalent.
Action
- Use the recommended Cummins® electronic service tool or equivalent.
- Verify the present aftertreatment diesel exhaust fluid controller software phase.
Specification
- If the aftertreatment diesel exhaust fluid controller software phase revision is not the latest, then proceed to the Repair section.
Linked Solutions
- None
Repair
- Download the updated diesel exhaust fluid controller 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.
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.
Solution: S00002906
Verification
Conditions
- None
Action
- Verify all preceding solution verifications for this fault code have been performed.
Specification
- If the fault code is still active after all the preceding solution verifications have been performed, then a malfunctioning aftertreatment diesel exhaust fluid controller has been detected.
Linked Solutions
- None
Validation
- None
Solution: S00001431
Verification
Conditions
- None
Action
- Verify all preceding solution verifications for this fault code have been performed.
Specification
- If the fault code is still active or inactive with more than one count within the last 25 engine hours and all the preceding solution verifications have been performed, 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.