PISTON 5I4997 - Caterpillar

Use this procedure in order to troubleshoot abnormal oil filter differential pressure. Also, use this procedure if one of the following diagnostic codes is active.
Table 1
Diagnostic Codes Table
J1939 Code and Description Conditions which Generate this Code System Response
99-15
Engine Oil Filter Differential Pressure : High - least severe (1) The difference between the filtered oil pressure and the unfiltered oil pressure is greater than the trip point pressure. The code is logged.
The ECM may derate the engine or shutdown the engine.
99-16
Engine Oil Filter Differential Pressure : High - moderate severity (2)
99-0
Engine Oil Filter Differential Pressure : High - most severe (3) Probable Causes
Oil filter
Oil pressure sensor circuit
Oil filter bypass valveRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in the order of the listed test steps.
Table 2
Troubleshooting Test Step Value Result
1. Plugged Oil Filter or Faulty Oil Filter
A. Manually check the oil filter differential pressure. If the oil filter differential pressure is too high, change the oil filter elements.
Oil Filter
Result: After starting the engine, the event code is no longer active for the filter that was changed.
STOP
Result: After starting the engine, the event code remained active for the filters that were changed.
Proceed to the Test Step 2.
2. Oil Pressure Sensors and/or Circuits
A. Do not start the engine. Use the Caterpillar Electronic Technician (ET) to compare the readings of the "Unfiltered Oil Pressure (abs)" and the "Engine Oil Pressure (abs)".
Sensor Circuit
Result: Both sensors read atmospheric pressure while the engine is off.
Proceed to the Test Step 3.
Result: A sensor does not read atmospheric pressure while the engine is off.
Repair: Troubleshoot the sensor circuit. Refer to Troubleshooting, "Sensor Signal (Analog, Active) - Test".
Verify that the repair eliminated the problem.
3. Oil Filter Bypass Valve
An oil filter bypass valve that is stuck in the closed position can cause a high reading for differential pressure when the oil is cold.
An oil filter bypass valve that is stuck in the open position can cause a low reading for differential pressure when the oil is hot.
A. Determine if the valve is stuck.
Filter Bypass Valve
Result: The bypass valve is OK.
STOP
Result: The bypass valve is NOT OK.
Repair: Repair the valve or replace the valve.
Verify that the repair eliminated the problem.
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).