ROD 4900125 - Caterpillar

OK - A valid duty cycle or a valid frequency is not present at the speed control.Repair: Verify that battery voltage is present to the speed control. Verify that the potentiometer that provides the variable resistance to the speed control is functioning properly. If the battery voltage is present and the potentiometer is operating correctly, replace the speed control.STOPTest Step 6. Check the Frequency and the Duty Cycle of the Remote Throttle Signal
Turn the local/remote switch on the control panel to the OFF/RESET position.
If your circuit is representative of the circuit in Illustration 2, perform the following steps.
Remove wire M971-GY from TBX-12 in the user interface panel.
Turn the local/remote switch on the control panel to the LOCAL position.
Measure the duty cycle between wire M971-GY and engine ground.Note: Set the multimeter to "VDC". Press the "Hz" button twice so that the % symbol is displayed.
Adjust the throttle from low idle to high idle.
Turn the local/remote switch on the control panel to the OFF/RESET position.
Replace all wires to the original configuration.
If your circuit is representative of the circuit