C175 Petroleum Engine Caterpillar

Oil Filter Differential Pressure Problem - If Equipped with the Self-Cleaning Oil Filter

Usage:

Use this procedure to troubleshoot an abnormal oil filter differential pressure. Also, use this procedure if one of the following event codes is active or logged.

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Table 1
J1939 Codes and Description	CDL Codes and Description	Comments
99-0 Engine Oil Filter Differential Pressure : High - most severe (3)	E99 (3) High Oil Filter Differential Pressure	The difference between the filtered oil pressure and the unfiltered oil pressure is greater than the trip point pressure. The code is logged.
99-15 Engine Oil Filter Differential Pressure : High - least severe (1)	E99 (1) High Oil Filter Differential Pressure	The difference between the filtered oil pressure and the unfiltered oil pressure is greater than the trip point pressure. The code is logged.
99-16 Engine Oil Filter Differential Pressure : High - moderate severity (2)	E99 (2) High Oil Filter Differential Pressure	The difference between the filtered oil pressure and the unfiltered oil pressure is greater than the trip point pressure. The code is logged.

Probable Causes

Codes
Oil filter not indexing
Sensor
Connectors and wiring
Self-Cleaning Filter
Oil Filter (if equipped)

Recommended Actions

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Table 2
Troubleshooting Test Step	Value	Result
1. Check for Codes A. Connect Cat^® Electronic Technician (ET) to the service tool connector. Note: Download the "Progress Status Report" before performing any troubleshooting. B. Look for active codes that are associated with the system for the event code.	Codes	Result: A code is active or logged. Proceed to Test Step 2. Result: An associated code is active. Repair: Troubleshoot any associated codes before continuing with this test. If the problem is not resolved, proceed to Test Step 2.
2. Inspect the Electrical Connectors and the Wiring A. Turn the main disconnect switch to OFF. B. Thoroughly inspect the connectors. Refer to Troubleshooting, "Electrical Connectors-Inspect" for additional information. C. Perform a 45 N (10 lb) pull test on the connector wires. D. Check the harness for abrasions and pinch points.	Connectors and Wiring	Result: The connectors and/or wiring appear to be OK. Proceed to Test Step 3. Result: There is a problem with the connectors and/or wiring. Repair: Repair or replace the connectors or wiring. Ensure that all the seals are properly in place and ensure that the connectors are coupled.
3. Check the Oil Pressure Sensors A. Connect Cat ET. B. Use Cat ET to compare the status of the following parameters while the engine is OFF: - "Unfiltered Oil Pressure" - "Engine Oil Pressure"	Parameter	Result: The sensors read 0 ± 14 kPa (0 ± 2 psi) while the engine is off. Proceed to Test Step 4. Result: A sensor does not read 0 ± 14 kPa (0 ± 2 psi) while the engine is off. Repair: Replace the faulty oil pressure sensor. Verify that the repair resolved the issue. Return to service.
4. Inspect the Self-Cleaning Oil Filter (SCF) Hydraulic Motor A. Inspect the hydraulic motor by placing a paint mark on the bolt on the distributor shaft end. Observe if the mark rotates slowly while the engine is running. B. Start the engine C. Observe the mark on the hydraulic motor and see if it rotates slowly. D. Measure the amount of time it takes for one revolution. Note: 1 rotation of the hydraulic motor should take between 2 to 4 minutes.	Hydraulic Motor	Result: One revolution took more than 10 minutes. Proceed to Test Step 5. Result: One revolution takes less than 10 minutes.
5. Check The Hydraulic Motor A. Manually turn the hydraulic motor 2 revolutions in 30 seconds. B. Start the engine and allow it to reach normal operating temperatures. C. Connect Cat ET.	Codes	Result: There are codes present. Proceed to Test Step 6. Result: There are no codes present. Repair: Replace the hydraulic motor. Verify that the repair resolved the issue. Return to service.
6. Check the Centrifugal Oil Filter (COF) A. Turn the keyswitch to OFF. B. Clean the COF per the Operation and Maintenance Manual. Replace the element making sure that the rotor nozzles are not plugged. C. Remove, inspect, and clean the SCF backflush line to the COF to make sure that there are no blockages. D. Start the engine and allow it reach normal operating temperature. E. Connect Cat ET. F. Once normal operation temperatures have been reached, allow the engine to run for 20 minutes. G. Monitor the system for fault codes for the 20 minutes of operation.	Centrifugal Oil FIlter	Result: There are codes present. Proceed to Test Step 7. Result: There are no codes present. Return to service.
7. Replace the Self-Cleaning Oil Filter (SCF) Assembly A. Turn the keyswitch to OFF. B. Replace the SCF assembly.	Self-Cleaning Oil Filter	Result: The SCF assembly was replaced. Repair: Verify that the repair eliminated the problem by allowing the engine to run for 3 minutes while the coolant temperature is above 20° C (68° F).

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).