Overview
| CODE | REASON | EFFECT |
| Fault Code: 1684 PID: SPN: 3363 FMI: 4/4 LAMP: Amber SRT: |
Low signal voltage detected at the aftertreatment diesel exhaust fluid tank heater circuit.
|
Possible reduced engine performance.
|
Circuit Description
The aftertreatment diesel exhaust fluid tank heater keeps the diesel exhaust fluid from freezing in the diesel exhaust fluid tank. The tank heater consists of an electrically powered tank heater control valve which controls the flow of engine coolant to a heating coil inside the diesel exhaust fluid tank. The tank heater control valve opens to allow coolant to flow to the heating coil when heating is commanded, and closes when heating is no longer required.
Component Location
The diesel exhaust fluid tank heater control valve is located near the diesel exhaust fluid tank. Specific location will vary depending on the OEM. The tank heating coil is internal to the diesel exhaust fluid tank.
Conditions for Running the Diagnostics
This diagnostic runs continuously when diesel exhaust fluid tank heating is being commanded.
Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected low signal voltage or a short to ground at the diesel exhaust fluid tank heater circuit.
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.
Diesel exhaust fluid tank heating 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 diesel exhaust fluid tank heater control valve
A short circuit to ground
Troubleshooting Summary
Solution: S00002870
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the aftertreatment diesel exhaust fluid tank heater control valve from the OEM wiring harness.
Action
- Inspect the pins and connectors for damage.
- Run the engine at idle.
- Connect the recommended Cummins® electronic service tool or equivalent.
- Wait 30 seconds before checking the circuit response.
- Use the recommended Cummins® electronic service tool or equivalent to read the fault codes.
Specification
- A malfunctioning aftertreatment diesel exhaust fluid tank heater control valve has been detected if the following fault code became active with the valve disconnected: 1683
Linked Solutions
- None
Repair
- Repair or replace the aftertreatment diesel exhaust fluid tank heater control valve.
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: S00000661
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the OEM wiring harness connector from the ECM.
- Disconnect the aftertreatment diesel exhaust fluid tank heater control valve from the OEM wiring harness.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid tank heater control valve SIGNAL pin at the OEM wiring harness ECM connector and engine block ground.
- Measure the resistance between the aftertreatment diesel exhaust fluid tank heater control valve SUPPLY pin at the OEM wiring harness ECM connector and engine block 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
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: S00000659
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the OEM wiring harness connector from the ECM.
- Disconnect the aftertreatment diesel exhaust fluid tank heater control valve from the OEM wiring harness.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance between the aftertreatment diesel exhaust fluid tank heater control valve SIGNAL pin at the OEM wiring harness ECM connector and all other pins in that connector.
- Measure the resistance between the aftertreatment diesel exhaust fluid tank heater control valve SUPPLY pin at the OEM wiring harness ECM connector and all other pins in that 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.
If all steps have been completed and no root cause has been identified, then follow the technical escalation process.