C175 Tier 4 Final Engines for Off-Highway Trucks Caterpillar

Crankcase Pressure Is High

Usage:

793F D3T

Use this procedure to troubleshoot high crankcase pressure or use this procedure if the following event code is active.

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Table 1
J1939 Code and Description	CDL Code and Description	Conditions which Generate this Code
N/A	E101(1) High Crankcase Pressure Warning	The engine crankcase pressure is greater than the trip point pressure for the programmed delay time. The code is logged.

Probable Causes

Engine oil level
Plugged crankcase breather
Sensor
Worn engine components

Recommended Actions

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Table 2
Troubleshooting Test Steps	Values	Results
1. Check the Engine Oil Level	Engine oil level	Result: The engine oil level is OK. Proceed to Test Step 2. Result: The engine oil level is high. Repair: Troubleshoot the cause of the incorrect oil level. If the problem is not resolved, proceed to Test Step 2.
2. Check the Crankcase Breather A. Check for a plugged crankcase breather. Note: If the engine is running in cold ambient temperatures, check to ensure that the breather tube is not plugged with ice.	Crankcase Breather	Result: The crankcase breather is plugged. Repair: Replace the crankcase breather. Note: A plugged crankcase breather can cause the crankshaft seal to leak. Sealing of the piston rings can be lost and the increase in crankcase blowby will increase the crankcase pressure. Result: The crankcase breather is not plugged. If the problem is not resolved, proceed to the Test Step 3.
3. Check the Crankcase Pressure Sensor A. Connect Cat^® Electronic Technician (ET). B. Turn the keyswitch to ON. Do not start the engine. C. Remove the oil filler cap. D. Monitor the crankcase pressure and the atmospheric pressure in Cat ET.	Crankcase pressure sensor	Result The crankcase pressure is within 3.5 kPa (0.5 psi) of the atmospheric pressure. Proceed to Test Step 4. Result The crankcase pressure is not within 3.5 kPa (0.5 psi) of the atmospheric pressure. Repair: Replace the crankcase pressure sensor. If the problem is not resolved, proceed to the Test Step 4.
4. Inspect the Electrical Connectors and the Wiring A. Turn the main disconnect switch to OFF. B. Thoroughly inspect the crankcase pressure sensor and atmospheric pressure sensor connectors. Refer to Troubleshooting "Electrical Connectors-Inspect" for details. C. Perform a 45 N (10lb) pull test on each of the wires for the two sensors. D.Check the harness for abrasions and for pinch points from sensors back to the ECM.	Electrical Connectors and Wiring	Results: The harness and connectors are OK. Proceed to Test Step 5. Results: There is a problem with the connectors and/or wiring. Repair: Repair the wiring or connectors and/or replace the connectors or wiring. Ensure that all the seals are properly in place and ensure that the connectors are coupled. If the problem is not resolved, proceed to the Test Step 5.
5. Inspect for an Internal Engine Problem Note: Damaged pistons or rings can cause too much pressure in the crankcase. This condition will cause the engine to run rough. The quantity of fumes (blowby) entering the CCV system will be above normal. The CCV system can become restricted quicker, which can cause oil leakage at the gaskets and seals which would not normally have leakage. Blowby can also be caused by worn valve guides or by a failed turbocharger seal. A. To determine whether the piston rings leak, measure the crankcase blowby. Refer to Systems Operation/Testing and Adjusting for additional information. - 285-0901 Blowby Tool Gp - 348-5430 Multi-Tool Gp Refer to Special Instruction , REHS7857, Testing for Excessive Cylinder Blowby in 3500 Engines for additional information.	Damaged or worn engine parts	Result There are worn or damaged engine parts. Repair: Repair or replace the worn or damaged parts. 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).