Overview
| CODE | REASON | EFFECT |
| Fault Code: 3237 PID: SPN: 4340 FMI: 3/3 LAMP: Amber SRT: |
High signal voltage detected at the diesel exhaust fluid line heater 1 circuit.
|
Possible reduced engine performance. |
Circuit Description
The aftertreatment diesel exhaust fluid line heaters are used to defrost and/or prevent freezing of the diesel exhaust fluid lines.
Component Location
The aftertreatment diesel exhaust fluid line heater 1 is located on the supply line between the diesel exhaust fluid dosing unit and the diesel exhaust fluid dosing valve.
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 Engine Control Module (ECM) detected the line heater voltage was above a calibratible value and the line heater current was above 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.
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, and then use the recommended Cummins® electronic service tool or equivalent to perform the Diesel Exhaust Fluid Doser System Heater Test found under ECM Diagnostic Tests.
- 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
A short circuit to battery in the OEM harness
Malfunctioning aftertreatment diesel exhaust fluid controller.
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: S00002879
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 between the appropriate aftertreatment diesel exhaust fluid line heater SIGNAL pin and the appropriate aftertreatment diesel exhaust fluid line heater RETURN pin at the appropriate aftertreatment diesel exhaust fluid line heater connector.
- 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.
Refer to OEM Service Manual
Linked Solutions
- None
Repair
- Replace the aftertreatment diesel exhaust fluid line heater.
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: S00003198
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid line heater from the aftetreatment diesel exhaust fluid controller harness.
Action
- Inspect the pins and connectors for damage.
- Turn keyswitch ON.
- Connect the recommended Cummins® electronic service tool or equivalent.
- Perform the Diesel Exhaust Fluid Doser System Heater Test under the ECM Diagnostic Tests menu.
- Use the recommended Cummins® electronic service tool or equivalent to read the fault codes.
Specification
- A malfunctioning aftertreatment diesel exhaust fluid line heater has been detected if the following fault code became active with the aftertreatment diesel exhaust fluid line heater disconnected: 3258
Linked Solutions
- None
Repair
- Replace the aftertreatment diesel exhaust fluid line heater.
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: S00000783
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid line heater from the OEM wiring harness.
- Disconnect the aftertreatment diesel exhaust fluid line heater relay 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 line heater SIGNAL pin at the OEM wiring harness ECM connector and all other pins in the OEM 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
- 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: S00003985
Verification
Conditions
- Turn keyswitch OFF.
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 proceed to the Repair section.
Linked Solutions
- None
Repair
Repair or replace only the components that were found to be out of specification.
- Replace the aftertreatment diesel exhaust fluid line heater.
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.
If all steps have been completed and no root cause has been identified, then follow the technical escalation process.