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 OFF.
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 may be reduced.
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
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: S00001123
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 system: 3422, 3562, 3563
Linked Solutions
- None
Repair
- Perform a search on the appropriate fault codes.
Validation
- None
Solution: S00006541
Verification
Conditions
- Turn keyswitch OFF.
Specification
- Proceed to the Repair section if the Technical Service Bulletin is applicable.
Linked Solutions
- None
Repair
- Complete the action outlined in the Technical Service Bulletin.
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: S00000796
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid line heater relay from the OEM wiring harness.
Action
- Inspect the pins and connectors for damage.
- Check the relay.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- If the relay does not meet specification, then a malfunctioning relay has been detected.
Linked Solutions
- None
Repair
- Replace the aftertreatment diesel exhaust fluid line heater relay.
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: S00001131
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.
- Connect the OEM wiring harness to the ECM.
Action
- Inspect the pins and connectors for damage.
- Turn keyswitch ON.
- Measure the voltage between the aftertreatment diesel exhaust fluid line heater SIGNAL pin and the aftertreatment diesel exhaust fluid line heater RETURN pin at the aftertreatment diesel exhaust fluid line heater connector of the OEM wiring harness.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- A malfunctioning OEM wiring harness has been detected if the voltage is within the following specification of battery voltage: 1 VDC
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.