C15 and C18 – Diesel Particulate Filter Has High Inlet Pressure

A. Establish communication between the Caterpillar Electronic Technician (ET) and the engine Electronic Control Module (ECM).

B. Download the “Warranty Report” from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.

C. Determine if any of the codes in Table 2 are present.

Proceed to Test Step 2.

Result: An associated diagnostic trouble code is present.

Refer to Troubleshooting, “Diagnostic Trouble Codes” in order to troubleshoot the associated diagnostic code.

If the problem is not resolved, proceed to Test Step 2.

A. Determine the most recent cleaning of the Diesel Particulate Filter (DPF).

Proceed to Test Step 3.

Result: The diesel particulate filter was not cleaned within the last 5000 hours.

Proceed to Test Step 4.

A. Reset all active codes and clear all logged codes by cycling the keyswitch to the Off position.

B. Remove the DPF.

C. Check for contamination on the face of the DPF and the Diesel Oxidation Catalyst (DOC).

Perform the following procedure:

1. Clean the DPF. Refer to the engines “Diesel Particulate Filter (DPF) Cleaner Manual” for the cleaning procedure.

2. Cleaning the DPF is not an ash service cleaning. Do not reset the engine ash model. The ash cannot be removed from the DPF if soot is present.

3. Reconnect the DOC and the DPF.

4. 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.

If the 1156-1 or 3609-15 diagnostic code remains active replace the DPF. Refer to Special Instruction, REHS5045, “Diesel Particulate Filter (DPF) Maintenance on Tier 4 Products Equipped with a Diesel Particulate Filter (DPF)”. Return the unit to service.

A. Reset all active codes and clear all logged codes by cycling the keyswitch to the Off position.

B. Clean the DPF. Refer to Special Instruction, REHS5045, “Diesel Particulate Filter (DPF) Maintenance on Tier 4 Products Equipped with a Diesel Particulate Filter (DPF)”. Refer to Systems Operation and Testing and Adjusting, “Diesel Particulate Filter – Clean” for the correct procedure.

C. Perform an “ARD Ignition Test” in Cat ET. Check for the 1156-1 or 3609-15 diagnostic code.

The ARD Ignition Test cannot be performed if the DPF soot loading is above 80%. When the DPF soot loading is above 80%, the Manual DPF Regeneration must be performed using Cat ET.

Return the unit to service.

Result: The 1156-1 or 3609-15 diagnostic code is active.

Replace the DPF. Reset all active codes and clear all logged codes by cycling the keyswitch to the Off position. Perform an “ARD Ignition Test” in order to verify that the problem is resolved.

Return the unit to service.