SHOE-TRACK 3P1134 - Caterpillar

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 −Battery 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 Engine Control Switch (ECS) is turned to the ON position, the engine will begin the sequence for start-up. When the emergency stop switch is activated the ECM will stop firing the injectors. The engine will stop. When an emergency stop signal is received by the ECM, the ECM will activate the output for the solenoid valve that controls the air shutoff valve. When the solenoid valve activates, the air shutoff valve closes removing the intake air to the engine. The air shutoff valve must be manually opened in order to start the engine.Note: The air shutoff is optional. A programmable parameter needs to be set with Caterpillar Electronic Technician (ET) in order to enable the air shutoff.The electrical power to the input for the keyswitch must be turned OFF for three seconds in order to reset the engine ECM after an emergency stop condition.
Illustration 1 g01382553
Typical schematic
Illustration 2 g01382204
P1 ECM connector
(P1-23) Emergency stop signal 1
(P1-28) Emergency stop signal 2
Illustration 3 g01382207
Customer connector
(Terminal 22) Emergency stop signal 1
(Terminal 23) Emergency stop signal 2
Illustration 4 g01234146
Location of ECM connectors
Test Step 1. Check for an Active Diagnostic Code
Turn the main disconnect switch to the ON position.
Start Cat ET.
Check for an active 337-2 diagnostic code. Expected Result:The 337-2 diagnostic code is not active.Results:
OK - The 337-2 diagnostic code is not active. Proceed to Test Step 2.
Not OK - The 337-2 diagnostic code is active.Repair: If the diagnostic code 337-2 is active, the wires between the ECM and the emergency stop switch are in opposite states. Check the wires for an open circuit.
Turn the main disconnect switch to the OFF position.
Disconnect the J1/P1 ECM connector.
Measure the resistance between P1-23 at ECM connector P1 and terminal 2 at the emergency stop switch.
Measure the resistance between P1-28 at ECM connector P1 and terminal 2 at the emergency stop switch. If a resistance measurement indicates an open circuit, repair the wires and/or connectors between the emergency stop switch and the ECM.STOPTest Step 2. Check the Status while the Emergency Stop Switch is Active
Turn the main disconnect switch to the ON position.
Start Cat ET.
Observe the status of the emergency stop switch on Cat ET.
Activate the emergency stop switch. If multiple emergency stop switches have been installed, ensure that any