SEAL-SPLIT BEARING 6V8545 - Caterpillar

System Operation Description:This procedure checks the circuits for the air shutoff system. The Electronic Control Module (ECM) does not provide diagnostics for the circuits that are for the air shutoff system.There are two conditions which can cause the ECM to activate the air shutoff:Engine Overspeed - The first condition occurs when the ECM detects an engine overspeed condition. The ECM energizes the output for the air shutoff solenoid and the fuel injection is disabled. The air shutoff system is latched by the ECM until the keyswitch is cycled.System test - The second condition occurs when a test of the air shutoff system is performed. The overspeed verify switch can be activated by the operator in order to perform this test. The engine speed is then increased to 90 percent of the programmed overspeed setpoint. The ECM activates the air shutoff system as the engine speed exceeds 90 percent of the programmed overspeed setpoint. The ECM energizes the air shutoff solenoid and fuel injection is disabled. The air shutoff system is latched by the ECM until the keyswitch is cycled.Note: If the "Air Shutoff" parameter is set to "Not Installed", the functionality for the overspeed verify switch remains operational. If the switch is activated during engine operation, the ECM will disable injection for any engine speed over 90 percent of the programmed overspeed setpoint. As the engine speed drops below 90 percent of the programmed overspeed setpoint, the injection is again enabled by the ECM. This functionality is not latched by the ECM and the functionality is disabled when the switch is turned off.For some air shutoff systems, after the air shutoff mechanism has been tripped, a manual reset of the mechanism may be necessary.
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Schematic for the air shutoff systemTest Step 1. Inspect the Electrical Connectors and the Wiring
Remove electrical power from the ECM.
Turn the keyswitch to the OFF position.
Verify that the air shutoff mechanisms are set to the OPEN position.
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ECM connectors (typical example) (1) J1/P1 ECM connectors
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Customer connector (typical example) (2) Customer connector
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Air shutoff mechanism (3) Terminals for the air shutoff solenoid
Thoroughly inspect connectors (1) and (2). Also, thoroughly inspect connections (3) at the air shutoff solenoid. Refer to Troubleshooting, "Electrical Connectors - Inspect".
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P1 terminals for the air shutoff system (P1-11) Air shutoff relay (P1-54) Overspeed verify switch (P1-67) Return
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the air shutoff system.
Check the allen head screw on each ECM connector for the proper torque. Also, check the allen head screw on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from the air shutoff solenoid to the ECM.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted, and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The connectors and wiring appear to be