BASE-OIL FILTER 4939731 - Caterpillar

Table 1
Event Code    
Code and Description    Conditions which Generate this Code    System Response    
E99(1) Engine Oil Filter Restriction Warning     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
Oil filter
Oil pressure sensors and/or circuitsRecommended Actions
Oil Filters
Check the oil filter differential pressure. If the oil filter differential pressure is too high, the problem is probably a plugged oil filter. Replace the oil filter elements.Inspect the condition of the oil filters. Replace any suspect oil filter.Oil Pressure Sensors and/or Circuits
Use the Cat ET to compare the readings of the "Unfiltered Oil Pressure (abs)" and the "Engine Oil Pressure (abs)" while the engine is off. Check that the sensors are correctly wired.If a reading is different from the atmospheric pressure, troubleshoot the sensor circuit. Refer to Troubleshooting, "Sensor Signal (Analog, Active) - Test".