Overview
| CODE | REASON | EFFECT |
| Fault Code: 3426 PID: SPN: 4346 FMI: 3/3 LAMP: Amber SRT: |
High signal voltage detected at the diesel exhaust fluid line heater 4 circuit.
|
Possible reduced engine performance. |
Circuit Description
The aftertreatment diesel exhaust fluid line heater relay is used to provide power to the aftertreatment diesel exhaust fluid line heaters.
Component Location
The aftertreatment diesel exhaust fluid line heater 4 is internal to the aftertreatment diesel exhaust fluid dosing unit and can not be serviced separately.
Conditions for Running the Diagnostics
This diagnostic runs when the keyswitch is in the ON position and line heating is commanded ON.
Conditions for Setting the Fault Codes
The aftertreatment diesel exhaust fluid controller detected the heater voltage was greater than a calibratible value.
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.
The line heater will be disabled.
- 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:
Malfunctioning line heater internal to the dosing unit.
A short circuit to battery in the OEM harness
Malfunctioning aftertreatment diesel exhaust fluid contoller.
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: S00010308
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid line heater from the OEM wiring harness.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance of the aftertreatment diesel exhaust fluid line heater.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- If the resistance is not within specification, then proceed to the Repair section.
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: S00003389
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the appropriate aftertreatment diesel exhaust fluid line heater 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 line heater SIGNAL pin at the aftertreatment diesel exhaust fluid controller harness 86-pin connector and all other pins in the connector.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- A malfunctioning aftertreatment diesel exhaust fluid controller wiring harness has been detected if the resistance is less than the following specification: 100k Ω
Linked Solutions
- None
Repair
- Repair or replace aftertreatment diesel exhaust fluid controller wiring 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.