RETAINER-PIN 2502940 - Caterpillar

Emergency shutoff controls are for EMERGENCY use ONLY. DO NOT use emergency shutoff devices or controls for normal stopping procedure.
Pressing the Emergency Stop Button may cause unburned gas to remain in the air inlet and in the exhaust manifold.
Unburned gas in the air inlet and exhaust system may ignite when the engine is started. Personal injury and/or property damage may result.Before starting an engine that may contain unburned gas, purge the unburned gas from the air inlet and exhaust system. Refer to the topic on purging unburned gas in the "Starting the Engine" section.
Emergency Stop Button
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"EMERGENCY STOP" button on the junction boxThe emergency stop button is in the OUT position for normal engine operation. For an emergency stop, press the emergency stop button. This shuts off both the fuel and the ignition.Ensure that any system that provides external support to the engine is secured after the engine is stopped.
Do not start the engine until the problem necessitating the emergency stop has been located and corrected.
The engine will not restart when the button is locked. To reset the button, pull the button or turn the button clockwise. The spring-loaded button will return to the OUT position.The control system must also be reset before the engine will start. Turn the engine control switch to the STOP position.The customer may also provide other means for emergency stopping. For instructions on operation, refer to the literature that is provided by the original equipment manufacturer.Unplanned Shutdowns
Abnormal operating conditions may cause an engine shutdown. The fuel will be shut off, but the ignition may not be shut off. Emergency stops and overspeed shutdowns cause the ignition to be shut off.An indication of the cause will be generated by the engine control module. The event code or the diagnostic code can be obtained with a Cat Electronic Technician (ET). For more information on event codes and diagnostic codes, refer to Troubleshooting.