The ARD nozzles can become plugged with carbon or with debris. The engine is equipped with a system that cleans the nozzles. The Engine Control Module (ECM) periodically tests the condition of the nozzles. The ARD combustion head contains an electric heating element. The heating element operates periodically in order to clean the nozzles.
This procedure covers the following diagnostic trouble codes.
| Diagnostic Trouble Codes for the Cleaning System for the Nozzles | ||
|---|---|---|
| Code | Description | Comments |
| 4301-5 | Aftertreatment #1 Fuel Injector #1 Heater Control : Current Below Normal | This code indicates that there is low current flow between the ECM and the relay for the heating element. The most likely cause of this code is an open circuit in the wiring between the ECM and the relay. There may be a problem inside an electrical connector. |
| 4301-6 | Aftertreatment #1 Fuel Injector #1 Heater Control : Current Above Normal | This code indicates that there is excessive current flow between the ECM and the relay for the heating element. If the excessive current flow continues for approximately ten seconds, the ECM disables the output for the heating element. The power to the ECM must be cycled in order to reset the fault detection circuit. The most likely cause of this code is a short circuit in the wiring between the ECM and the relay. There may be a problem inside an electrical connector. |
| Follow the troubleshooting procedure in order to identify the root cause of the problem. | ||
Test Step 1. Determine the Diagnostic Code
- Connect Cat ET to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
- Determine if a diagnostic trouble code is present.
Results:
- A 4301-5 or a 4301-6 diagnostic code is present. - Proceed to Test Step 2.
- There is no diagnostic code but there is a problem with the heater. - Proceed to Test Step 2.
Test Step 2. Check for Voltage at the Heater Relay
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| Illustration 1 | g01976754 |
Schematic drawing for the electric heating element | |
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| Illustration 2 | g01978955 |
Relay for the electric heating element | |
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| Illustration 3 | g01978973 |
ARD combustion head (1) Electrical connector for the heated nozzle (2) Fork bracket for the electrical connector (3) ARD combustion head with a heated nozzle | |
- Turn the keyswitch to the "ON" position.
- Check the voltage between terminal 3 and terminal 4 on the heater relay.
Results:
- The voltage is equal to battery voltage. - Proceed to Test Step 5.
- The voltage is not equal to battery voltage. - Proceed to Test Step 3.
Test Step 3. Check the Circuit Protection Device
- Check the circuit protection device located on the chassis in order to make sure that the protection device has not tripped.
Results:
- The circuit protection device has tripped. -
Repair: Reset the protection device. Override the heater relay. If the circuit protection device trips again, disconnect the connector to the heater at the ARD head. Reset the circuit protection device. Override the heater relay.
If the circuit protection device does not trip, replace the ARD head and proceed to Test Step 10. If the circuit protection device trips, there is a problem in the wiring circuit for the ARD heater. Check the circuit for a short to ground. Repair the wiring or replace the wiring. Proceed to Test Step 9.
- The circuit protection device has not tripped. - Proceed to Test Step 4.
Test Step 4. Check for Voltage at the Circuit Protection Device
- Measure the voltage at the incoming side of the circuit protection device.
Results:
- The voltage is equal to battery voltage. -
Repair: Check for continuity between terminal 4 on the heater relay and ground. If there is continuity, there is a problem with the wiring between the circuit protection device and the heater relay. Repair the wiring or replace the wiring. If there is not continuity between terminal 4 on the heater relay and ground, repair the wiring or replace the wiring.
Proceed to Test Step 9.
- The voltage is not equal to battery voltage. -
Repair: The problem is in the wiring between the circuit protection device and the battery. Repair the wiring or replace the wiring.
Proceed to Test Step 9.
Test Step 5. Check for Output Voltage at the ARD Heater Relay
- Turn the keyswitch to the "ON" position.
- Establish communication between Cat ET and the ECM . Refer to Troubleshooting, "Electronic Service Tools", if necessary.
- Override the heater relay and check the voltage between terminal 2 on the heater relay and a good ground source.
Results:
- The voltage is equal to battery voltage. - Proceed to Test Step 6.
- The voltage is not equal to battery voltage. -
Repair: Replace the heater relay.
Proceed to Test Step 9.
Test Step 6. Check for Continuity on the Wire Between the ARD Heater Relay and the ARD Nozzle Heater
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| Illustration 4 | g01978973 |
ARD combustion head (1) Electrical connector for the heated nozzle (2) Fork bracket for the electrical connector (3) ARD combustion head with a heated nozzle | |
- Remove the fork bracket from the ARD nozzle heater.
- Disconnect the wire to the ARD nozzle heater.
- Check for continuity between terminal "2" on the ARD heater relay and the connector for the ARD nozzle heater.
Results:
- There is continuity between terminal "2" on the ARD heater relay and the connector for the ARD nozzle heater. - Proceed to Test Step 7.
- There is not continuity between terminal "2" on the ARD heater relay and the connector for the ARD nozzle heater. -
Repair: Repair the wiring or replace the wiring between the ARD heater relay and the ARD nozzle heater.
Proceed to Test Step 9.
Test Step 7. Check for Continuity Between the ARD Nozzle Heater and a Good Ground Source
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| Illustration 5 | g02011774 |
Overview of the ARD head (5) Measurement location on the heated nozzle | |
- Check for continuity between the ARD nozzle heater and a good ground source.
Results:
- There is continuity between the ARD head and a good ground source. - Proceed to Test Step 8.
- There is not continuity between the ARD head and a good ground source. -
Repair: Replace the ARD combustion head.
Proceed to Test Step 10.
Test Step 8. Perform the ARD Nozzle Heater Current Test
- Perform an ARD nozzle heater current test. Refer to System Operation and Testing and Adjusting , "ARD Nozzle Heater (Current) - Test" for the correct procedure.
Expected Result:
The current flow is above 6.0 A for a 12 V system.
The current flow is above 3.0 A for a 24 V system.
Results:
- The current flow does not agrees with the above results. - The current flow is Not OK.
Repair: Replace the ARD head.
Proceed to Test Step 10.
- The current flow agrees with the above results. - The current flow is OK. Proceed to Test Step 9.
Test Step 9. Perform the ARD Fuel Nozzle Heater Cycle Override
- Perform the ARD fuel nozzle heater cycle by selecting the following menus on Cat ET:
- "Diagnostics"
- "Diagnostic Tests"
- "System Troubleshooting Settings"
- "ARD Fuel Nozzle Heater Cycle"
Run the ARD fuel nozzle heater cycle for one hour.
Results:
- The cycle completed successfully. - Proceed to Test Step 10.
Test Step 10. Perform a Service Regeneration
Note: This test must be performed through Cat ET. The Cat ET service tool enhances the diagnostics during the service test.
- Start a service regeneration by selecting the following menus on Cat ET:
- "Service"
- "Service Procedures"
- "Manual Diesel Particulate Filter Regeneration"
Cat ET will display a "Waiting On Requirements" window. The ECM will automatically elevate the engine speed.
The duration of the service regeneration depends on the soot load in the DPF. The ECM will automatically return the engine speed to low idle after the service regeneration is complete.
Note: The ECM tests the nozzles for plugging after the service regeneration is complete. An "Aftertreatment Fuel Injector #1 : Not Responding Properly" code will become active if the nozzles are plugged.
- "Service"
Expected Result:
The service regeneration was successful.
Results:
- The service regeneration completes successfully. - STOP