ENGINE AR-PRIMARY 3751284 - Caterpillar

Introduction
Do not perform any procedure in this Special Instruction until you read this information and you understand this information.Reference Electronics Application and Installation Guide Industrial Engines C7-C32 ACERT - PE, LEBH4623 for information about the engine in question.Safety Information
Improper jumper cable connections may cause an explosion resulting in personal injury. Batteries may be located in separate compartments. When using jumper cables, always connect positive (+) cable to positive (+) terminal of battery connected to starter solenoid and negative (−) cable from external source to starter negative (−) terminal. (If not equipped with starter negative terminal, connect to engine block.) Follow procedure in the Operation and Maintenance Manual.
When the emergency power off switch is used, high voltage still remains in the system.
Engine surfaces and fluids can be hot. A running engine will have moving belts exposed at the front of the engine (rear of bus). These hazards can result in personal injury or death. stop the engine while connecting test equipment and work carefully around a running engine. Do not allow tools or test equipment to protrude or vibrate into the path of rotating belts.
Air Shutoff Check
Check Overspeed Protection
To ensure that the overspeed protection is functional, an "Overspeed Verify" procedure should be carried out when initially packaged and at each oil change.
Confirm secure wiring connections between the Electronic Control Module (ECM), the air shut-off relay, the air shut-off solenoid, and the battery.
Carry out the 75% "Overspeed Verify" procedure by grounding the appropriate pin and commanding a desired speed beyond this point. There will be an overspeed warning before the actual overspeed shutdown. See the above listed publications guide for specific details on wiring an "Overspeed Verify" switch.
Ensure that the air shut-off has actuated. Do not assume that because the engine has shutdown, the air shut-off has closed.
Ensure that air shutoff is reset when completed.Check Air Shutoff Sealing
To ensure that the air shutoff valve always shuts down when the engine ingests gaseous fumes, perform the test below at each oil change. A test failure can indicate wear in the block off plate to valve body interface and/or the bearing system.
Place engine at low idle speed. Ensure all accessories that are normally used for the application are in use, like a fan, or power takeoffs.
Actuate the air shutoff manually. On electrical operator air shutoffs, utilize an applicable power supply or jumper cables from the battery to energize the air shut-off solenoid. Ensure that the solenoid receives only a momentary signal to prevent overheating. On hydraulic operator air shutoffs, found on some hazardous location units, actuate by pulling the emergency stop handle.
Ensure that air shutoff was actuated and that the engine comes to a complete stop.Note: As every application has different parasitic loads and inertia, the duration for the problem to occur cannot be specified. However, if the engine stumbles or attempts to continue running, these symptoms may be an indication that worn components may need replacement.If additional help is needed, contact the Dealer Solution Network.
Actuating the air shutoff valve may result