YOKE 8D4578 - Caterpillar

System Operation Description:Use this procedure if the following event code is active. Refer to Troubleshooting, "Diagnostic Trouble Codes" for information about this code.
Table 1
Diagnostic Trouble Code for High DPF Inlet Pressure    
J1939 Code    Code Description    Comments    
3609-15     Diesel Particulate Filter Intake Pressure 1 : High Least Severe     The inlet pressure at the Diesel Particulate Filter (DPF) is high.
There are no faults on the 5V sensor supply.
There are no faults for the battery voltage.
There are no faults for the DPF inlet temperature.    
Note: After using the electronic service tool to clear a 3479-xx diagnostic trouble code, the keyswitch must also be cycled.Test Step 1. Check for Associated Diagnostic Trouble Codes
Connect the electronic service tool to the diagnostic connector.
Turn the keyswitch to the ON position.
Download the following items before performing any troubleshooting or clearing any diagnostic codes:
Warranty Report
Aftertreatment Regeneration Trigger History
Product Status Report with Histograms
Use the electronic service tool to check for active diagnostic codes.Diagnostic code 3609-15 will normally have an associated high-level code. Troubleshoot the 3609-15 code before troubleshooting any of the high-level codes that are listed in Table 2.
Table 2
Associated High-Level Diagnostic Trouble Codes    
3473     31    
3474     31    
3711     31    Diagnostic code 3609-15 may have associated low-level codes. Troubleshoot the low-level codes that are listed in Table 3 before troubleshooting the 3609-15 code.
Table 3
Associated Low-Level Diagnostic Trouble Codes    
3719     0 or 16    
3720     15 or 16    Results:
An associated low-level diagnostic trouble code is not present. - Proceed to Test Step 2.
An associated low-level diagnostic trouble code is present. - Repair: Refer to Troubleshooting, "Diagnostic Trouble Codes" in order to troubleshoot the associated low-level diagnostic code. If the fault is not eliminated, proceed to Test Step 2.Test Step 2. Ash Service Maintenance
Determine the most recent ash service of the DPF.Results:
An ash service was performed within the last 5000 hours. - Proceed to Test Step 3.
An ash service was not performed within the last 5000 hours. - Proceed to Test Step 4.Test Step 3. Check for Contamination
Remove the DPF.
Check for contamination on the face of the DPF and the Diesel Oxidation Catalyst (DOC).Results:
The DOC and the DPF are not contaminated. - Repair: Contact the Technical Communicator at a Caterpillar dealer.STOP
There is oil, fuel, or coolant on the DPF and/or the DOC. - Repair: Perform the following procedure:
Take the DPF to an authorized dealer for repair.
Clean the DOC with compressed air.
Reconnect the DOC and the DPF.
Start the engine. Run the engine at 1400 RPM with no load. Run the engine for at least 15 minutes or run the engine until there is no more white smoke.Note: Running the engine until there is no more white smoke is not an ash service. Do not reset the"Diesel Particulate Filter Ash Service Reset".
If the 3609-15 diagnostic code remains active replace the DPF. Perform a "Manual Diesel Particulate Filter Regeneration".
Return the unit to service.STOPTest Step 4. Perform an Ash Service Test
Remove the DPF. Refer to