VARIABLE TIMING DRIVE ASSEMBLY 4S9398 - Caterpillar

Replacement Procedure
The new GSC must be reprogrammed after the GSC has been installed. If the GSC that is being replaced is functional, then make a note of the value for the hourmeter, all engine setpoints, any spare inputs, and any spare outputs that are programmed. See Systems Operation, "Engine/Generator Setpoint Viewing OP2".
Shut down the engine. Remove the positive lead wire from the battery.
Remove the harness connector from the GSC. A 4 mm hex wrench is required to turn the fastening screw.
Make sure that all of the wires at the terminal strips are marked with the respective termination point. During reassembly, these wires must be reattached to the correct terminal. Remove all of the wires from the terminals and the wires from the posts of the relay module.
Remove the six nuts that fasten the GSC to the front panel. Remove the GSC.
Place the new GSC in the front panel. Install the six nuts and tighten the six nuts.
Reconnect the harness connector to the GSC. Reconnect all the wires to the terminals of the relay module that were removed. Reconnect the positive lead wire to the battery. If necessary, see the "Generator Set Wiring Diagram" in Testing And Adjusting, "Schematics and Wiring Diagrams ".
Reprogram the setpoints, the spare inputs, the spare outputs, the hourmeter, the voltmeter, the ammeter and the AC offset adjustment. See the related topics in the Systems Operation. Use the values from the original GSC. See step 1.