SHAFT 4557981 - Caterpillar

refer to Disassembly and Assembly, "Camshaft Position Sensor - Remove and Install".
Use a flashlight in order to check the timing ring on the camshaft through the camshaft timing hole for damage.
Use a flashlight in order to check the crankshaft timing ring for damaged teeth or missing teeth. Ensure that the crankshaft timing ring has not been displaced from the crankshaft.Results:
Found fault with the crankshaft timing ring or the timing ring on the camshaft - Repair: If necessary, replace the camshaft. Refer to Disassembly and Assembly, "Camshaft - Remove" and refer to Disassembly and Assembly, "Camshaft - Install".If necessary, replace the crankshaft timing ring. Refer to Disassembly and Assembly, "Crankshaft Timing Ring - Remove and Install" .Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair has eliminated the fault.STOP
No faults found - Repeat this procedure from Test Step 3.Test Step 5. Measure the Supply Voltage at the Sensor Connector
Turn the keyswitch to the OFF position.
Disconnect the speed/timing sensor with the active diagnostic code.
Measure the voltage from terminal 1 on the sensor connector to engine ground.Note: The voltage should read 7.5 to 8.5 VDC.Expected Result:The readings agree with the values that are listed above.Results:
OK - The sensor is receiving the correct supply voltage. Proceed to Test Step 7.
Not OK - There is a fault with the 8 VDC supply.Repair: Repair the faulty connectors or the harness. Replace the faulty connectors or the harness. Reconnect all sensor and ECM connectors. Ensure that all of the seals are correctly in place. Ensure that all connectors are correctly coupled.Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair has eliminated the fault. STOPTest Step 6. Disconnect the Power Supply Connections for the Speed/Timing Sensors at the ECM
Turn the keyswitch to the OFF position.
Disconnect connector P2. Thoroughly inspect the P2/J2 connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for more information.
Remove the P2:44 (+8 V).
Reconnect the P2 connector to the ECM.
Turn the keyswitch to the ON position.
Use the electronic service tool to check for active diagnostic codes.Expected Result:One of the following diagnostic codes is still active after the terminals for sensor power have been disconnected:
678-3 ECU 8 Volts DC Supply : Voltage Above Normal
678-4 ECU 8 Volts DC Supply : Voltage Below NormalResults:
OK - Repair: Perform the following repair: Check the battery voltage at pins 61, 63, 65, 67 and 69 (Battery ground) on the P1 connector. Check the battery voltage at pins 48, 52, 53, 55 and 57 (Battery+) on the P1 connector.. The measured voltage should be between 22.0 VDC and 27.0 VDC.If the voltage is correct, then perform the following procedure.
Make sure that the latest flash file for the application is installed in the ECM. Refer to Troubleshooting, "Flash Programming".
Contact the Technical Communicator at a Caterpillar dealer.Note: This consultation can greatly reduce the repair time.
If the Technical Communicator recommends the use of a test ECM, install a test ECM. Refer to Troubleshooting,