C13, C15, and C18 Engines Troubleshooting – Crankcase Pressure Is Low

This procedure covers the following diagnostic trouble code:

Note: The following code may not be applicable for certain applications.

Table 1
Diagnostic Trouble Codes
CDL Code J1939 Code Description
(code descriptions may vary)
E994 (2) Low Crankcase Pressure The Engine Control Module (ECM) activates this code when the crankcase pressure has been below the minimum value for a programmed time period. The amber warning lamp is illuminated. The code is logged. Engine power is derated.

Illustration 1 g02211761
Typical crankcase ventilation system

(1) Crankcase pressure sensor

(2) Breather

(3) Filter housing

(4) Fumes disposal tube

Illustration 2 g02013955
Left side of the engine

(5) Check valve

Probable Causes

The oil fill cap is off.
The oil level gauge (dipstick) is not fully seated.
The vent filter for the crankcase is not installed.
The tube between the breather and the breather canister is not connected.
The engine is equipped with an open crankcase ventilation system.

Recommended Actions

Table 2
Troubleshooting Test Steps Values Results
1. Engine Ventilation

A. Establish communication between Caterpillar Electronic Technician (ET) and the ECM . Refer to Troubleshooting, “Electronic Service Tools”, if necessary.

B. Download the “Warranty Report” from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes.

C. Inspect the engine. Look for the conditions that are listed above.

Ventilation Result: The probable cause was found.

Make the necessary repairs.

Reset all active codes and clear all logged codes. Use Cat ET to verify that the problem is resolved.

Complete the procedure in the order in which the steps are listed.

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).


Posted in C18

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