FAULT CODE 3238
Aftertreatment 1 Diesel Exhaust Fluid Line Heater 1 Circuit – Voltage Below Normal or Shorted to Low Source
Overview
| CODE | REASON | EFFECT |
| Fault Code: 3238 PID: SPN: 4340 FMI: 4/4 LAMP: Amber SRT: |
Low signal voltage detected at the diesel exhaust fluid line heater 1 circuit.
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Possible reduced engine performance.
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Aftertreatment Diesel Exhaustl Fluid Line Heater 1 Circuit
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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 below a calibratible value and the line heater current was below a calibratable valure.
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 may be reduced.
Conditions for Clearing the Fault Code
- To validate the repair, perform a key cycle, and then use INSITE electronic service tool to perform the Diesel Exhaust Fluid Doser System Heater Test found under ECM Diagnostic Tests.
- The fault code status displayed by INSITE electronic service tool 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 INSITE electronic service tool 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:
A short circuit to ground in the OEM harness
A malfunctioning line heater
Troubleshooting Summary
- Check for primary fault codes
- Technical Service Bulletin is available
- Aftertreatment diesel exhaust fluid line heater relay resistance check
- Aftertreatment diesel exhaust fluid line heater relay SUPPLY voltage check
- Aftertreatment diesel exhaust fluid line heater relay open circuit check
- Aftertreatment diesel exhaust fluid line heater circuit pin to ground short
- Aftertreatment diesel exhaust fluid line heater pin shorted to another pin
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: 3562, 3563, 3564
Linked Solutions
- None
Repair
- Perform a search on the appropriate fault codes.
Validation
- None
Verification
Conditions
- Turn keyswitch OFF.
Action
- Technical Service Bulletin is available.
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.
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid line heater relay from the OEM wiring harness.
Action
- Check the relay.
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.
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.
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.
- Turn keyswitch ON.
- Measure the voltage between the aftertreatment diesel exhaust fluid line heater relay SUPPLY pin at the aftertreatment diesel exhaust fluid line heater relay OEM wiring harness connector and chassis ground.
- Refer to the circuit diagram or wiring diagram for connector pin identification.
Specification
- A malfunctioning fuse or OEM wiring harness has been detected if the voltage is not within the following specification of battery voltage: 1 VDC
Linked Solutions
- None
Repair
Repair or replace only the components that were found to be out of specification.
- Replace the fuse.
- Repair or replace the OEM wiring harness.
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.
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 relay feedback SIGNAL pin at the appropriate aftertreatment diesel exhaust fluid line heater relay OEM wiring harness connector and the appropriate aftertreatment diesel exhaust fluid line heater relay feedback SIGNAL pin at the OEM wiring harness ECM 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
Repair
- Repair or replace the OEM wiring harness.
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.
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 aftertreatment diesel exhaust fluid line heater connector and chassis ground.
- 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
Repair
- Repair or replace the OEM wiring harness.
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.
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
Repair
- Repair or replace the OEM wiring harness.
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.