SPRING-GAS 1572193 - Caterpillar

System Operation Description:The Electronic Control Module (ECM) receives two signals from the Emergency Stop Switch. The signals allow the ECM to determine the status of the Emergency Stop Switch. The ECM will shut down the engine when both of the signals are open. When both of the signals are connected to the digital return the Emergency Stop Switch is NOT active and the engine will run. Refer to Illustration 1.If two different signals are detected during the powerup, the ECM will determine that one of the signals is incorrect. A diagnostic code will be logged and a diagnostic code will remain active. The engine will continue to run when the ECM detects two different signals. If both of the signals are open, the engine will stop.The customer can install multiple Emergency Stop Switches. When the Start/Run/Stop Switches are active, the engine will begin the sequence for start-up. When an Emergency Stop Switch is active the fuel supply is cut off and the engine will not run. When an emergency stop signal is received by the ECM, the ECM will trigger the hydraulic solenoid valves that control the air shutoff valves. When the hydraulic solenoid valves activate, the air shutoff valves close removing the intake air to the engine.The right hand switch for the right air shutoff and the left hand switch for the left air shutoff are part of the emergency stop circuit. The right hand switch for the right air shutoff and the left hand switch for the left air shutoff are in the closed position when the air shutoff valves are open. The right hand switch for the right air shutoff and the left hand switch for the left air shutoff ensures that the ECM knows the position of the air shutoff valves. The air shutoff valves must be manually opened in order to start the engine.The main power to the ECM must be turned OFF for three seconds in order to reset the engine ECM after an Emergency Stop condition.
Illustration 1 g00861631
Typical exampleTest Step 1. Check for Connector Damage.
Disconnect main power.
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 pinch points.Expected Result:The connectors and wiring should be free of the following problems: damage, corrosion, abrasion and incorrect attachment.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 and/or wiring or replace the connectors and/or wiring.STOPTest Step 2. Check the Status while the Emergency Stop Switch is