G3500H Generator Set Engine Caterpillar

Crankcase Pressure Is Low

Usage:

Use this procedure to troubleshoot a high crankcase pressure. Also, use this procedure if one of the following event codes is active or logged.

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Table 1
J1939 Code and Description	Comments
101-1 Engine Crankcase Pressure : Low - most severe (3)	The engine crankcase pressure is lower than the trip point pressure for the programmed delay time. The code is logged.
101-17 Engine Crankcase Pressure : Low - least severe (1)	The engine crankcase pressure is lower than the trip point pressure for the programmed delay time. The code is logged.

Note: The crankcase pressure sensor is only available for the G3512H engine application.

Probable Causes

Oil level
Crankcase breather
Ventilation system (if equipped)
Sensor
Worn engine components

Recommended Actions

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Table 2
Troubleshooting Test Steps	Values	Results
1. Check the Engine Oil Level	Oil Level	Result: The engine oil level is OK. Proceed to Test Step 2. Result: The engine oil level is low. Repair: Troubleshoot the cause of the incorrect oil level. If the problem is not resolved, proceed to Test Step 2.
2. Check for a Missing or Damaged Crankcase Breather	Plugged Breather	Result: The crankcase breather is not missing or damaged. Proceed to Test Step 3. Result: The crankcase breather is missing or damaged. Repair: Replace the crankcase breather. If the problem is not resolved, proceed to Test Step 3.
3. Check the Crankcase Ventilation System Note: Engines may have a system for ventilation of the crankcase. A problem with the ventilation system can decrease the crankcase pressure below the minimum allowed setpoint. Engine crankcase pressure may be pulled to too low with a malfunctioning ventilation system.	Ventilation System	Result: The crankcase ventilation system is OK. Proceed to Test Step 4. Result: The crankcase ventilation system is NOT OK. Repair: For information on crankcase ventilation system, refer to the Original Equipment Manufacturers (OEM) service information. If the problem is not resolved, proceed to Test Step 4.
4. Check the Crankcase Pressure Sensor A. Connect Cat^® Electronic Technician (ET) to the service tool connector. B. Turn the main disconnect switch to the ON position. Do not start the engine. C. Remove the oil filler cap. D. Use Cat ET to monitor the following pressures: - Crankcase pressure	Sensor	Result: The crankcase pressure is within 0 ± 1 kPa (0 ± 4inch of H₂O) of 0 with the main disconnect switch in the ON position. Proceed to Test Step 5. Result: The crankcase pressure is not within 0 ± 1 kPa (0 ± 4inch of H₂O) of 0 with the main disconnect switch in the ON position. Proceed to Test Step 5.
5. Inspect the Electrical Connectors and the Wiring A. Turn the main disconnect switch to the OFF position. 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 wiring appear to be OK. Repair: Replace the sensor. 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.

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).