MOUNTING GP-ENGINE 4331899 - Caterpillar

The shutdown switch provides the ability to shut down the engine. The engine's ECM remains active. Caterpillar Electronic Technician (ET) can be used to communicate with the ECM. The shutdown switch must be returned to the RUN position and the engine rpm must be zero before the ECM will allow the engine to start.Two inputs to the ECM are required for the shutdown switch to operate correctly. The normally closed input must be grounded and the normally open input must be floating in order for the engine to run. If the shutdown switch is toggled, the normally closed input is floating and the normally open input is grounded. The engine will shut down. Refer to Table 2 for the different input configurations of the shutdown switch.
Table 2
Input State    
Normally Closed Input    Normally Open Input    Switch Status    
Closed     Closed     Invalid    
Closed     Open     Shutdown OFF    
Open     Closed     Shutdown ON    
Open     Open     Invalid    To shut down the engine, toggle the shutdown switch to the SHUTDOWN position. If the engine is running, the ECM disables the fuel injection. The status screen will display "INJECTION DISABLED".The ECM will not allow the engine to start if the status for the shutdown switch is "ON".
Illustration 1 g01419183
SchematicTest Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Illustration 2 g01415758
Location of ECM connectors
Thoroughly inspect the ECM connector J1/P1. Thoroughly inspect the connectors for the shutdown switch. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 3 g01419187
P1 ECM connector (P1-46) User defined shutdown (NO) (P1-47) User defined shutdown (NC)
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and the wiring for abrasion and for pinch points.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check the Status of the Shutdown Switch on Cat ET
Connect Cat ET to the service tool connector. Start Cat ET.
Turn the keyswitch to the ON position.
Observe the status of the shutdown switch on Cat ET.
Operate the shutdown switch. Observe the status of the shutdown switch on Cat ET.Expected Result:The status of the shutdown switch on Cat ET is ON when the shutdown switch is in the SHUTDOWN position.Results:
OK - The status of the shutdown switch on Cat ET is correct.Repair: The shutdown switch is operating normally. There may be an intermittent problem. If