SEAL-LIP TYPE 8S2225 - Caterpillar

System Operation Description:The customer's emergency stop switch sends two signals to the Electronic Control Module (ECM). The signals are used to determine if the emergency stop switch is active. The emergency stop switch is active when the switch is in the open state and the two signals are high. The emergency stop switch is inactive when the switch is in the closed state and the two signals are held low.If the ECM is powering up and one of the signals from the emergency stop switch is in a different state from the other signal, the ECM knows that one of the signals is faulty. If one of the signals from the emergency stop switch is in a different state from the other signal, the ECM will generate a diagnostic code that remains active until power to the ECM is cycled. The ECM will not allow the crank cycle to begin if the signals are opposite of each other. The ECM will allow the engine to be started manually in this state.The ECM monitors the emergency stop signals at all times. If the engine is running and one of the signals from the emergency stop switch changes states, the engine will continue to run. The ECM initiates an emergency stop shutdown only when both signals are high during engine operation.When a signal from the emergency stop switch is received, the ECM will activate the air shutoff solenoid.For safety, the ECM will not allow the starting sequence to begin when the emergency stop switch is activated. The engine will not be able to restart until the following conditions are met:
The engine rpm must equal zero.
The emergency stop inputs must go low.
The ECM has been reset.Note: If one of the signals from the emergency stop switch is in a different state from the other signal, the Caterpillar Electronic Technician (ET) will display the warning "INVALID DATA".
Illustration 1 g00728931
Typical exampleTest Step 1. Check for Connector Damage.
Turn the circuit breaker for the battery to the OFF position.
Turn the ECS to the OFF/RESET position.
Thoroughly inspect the ECM connectors J1/P1 and J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" for details.
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 of 6.0 N m (55 lb in).
Check the customer connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
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, and the harness and wiring are free of corrosion, of abrasion or of pinch points.Results:
OK - The connectors and wiring are okay. Proceed to Test Step 2.
Not OK - The connectors and/or wiring are not okay.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 2. Check the ON Status of the