PIN 3812745 - Caterpillar

probable root causes are listed in order below.
Shutdown switch
ECS or Start/Run/Stop Switch
Battery cables and/or batteries
Starting motor
Flywheel ring gear
Hydraulic cylinder lock
Internal engine problemPerform the following tests in order:
Ensure that the shutdown switch is in the OFF position. Use the Caterpillar Electronic Technician (ET) to confirm the switch status. Check for CID-FMI 337-02. If the CID-FMI is active, refer to the diagnostic functional test Troubleshooting, "Emergency Stop Switch". If your application has EMCP II, refer to Service Manual, SENR5398.
Check the Engine Control Switch (ECS) and verify proper operation. Use the Cat ET to confirm the switch status. If the engine has an ECS, refer to the diagnostic functional test Troubleshooting, "Engine Control Switch (ECS)". Check the Start/Run/Stop Switch and verify proper operation. Use the Cat ET to confirm the switch status. If the engine has a Start/Run/Stop Switch refer to the diagnostic functional test Troubleshooting, "Start/Run/Stop Switch".
The following items should be checked for loose connections and corrosion: Master Disconnect Switch, battery posts, battery and battery cables. Clean the cables and/or connections if corrosion is found. Load test the battery. Refer to Special Instruction, SEHS9249, "Use Of 4C4911 Battery Load Tester" for more information. If necessary, charge the batteries. Refer to Special Instruction, SEHS7633, "Battery Test Procedure".
Test the operation of the starting motor. Check the system wiring to the starting motor. If equipped, inspect the Caterpillar Prelubrication System for proper operation. Refer to the diagnostic functional test Troubleshooting, "Starting Motor System".
Ensure that the timing pin is not left in the flywheel housing after you set the valve lash. Use the 9S-9082 Engine Turning Tool and attempt to manually turn the engine.
Inspect the engine accessories if the engine will not turn. Remove the engine accessories and inspect the engine accessories that can lock up the engine. Repair the engine accessories and/or replace the engine accessories. Refer to Systems Operation for additional information.
Remove injectors and check for fluid in the cylinders.
Disassemble the engine. Inspect the engine for internal component damage. Refer to Disassembly and Assembly Manual.