DISC 3715087 - Caterpillar

to the loadshare unit. Check the supply voltage to the loadshare unit.STOPTest Step 3. Determine the Component that has Failed.
Determine if the problem is with the input for the throttle or the droop.
Turn the battery disconnect switch to the OFF position.
Connect the Caterpillar Electronic Technician (ET) to the engine ECM. Use the service tool connector J60/P60.
Turn the battery disconnect switch to the ON position.
Turn the ECS to the STOP position.
Observe the position of the throttle on the Cat ET as you turn the speed adjust potentiometer.
Observe the droop on the Cat ET as you turn the droop adjust potentiometer.Note: Do not overturn the droop adjust potentiometer in the clockwise direction. The signal will become erratic.
Turn the ECS to the OFF/RESET position.
Turn the battery disconnect switch to the OFF position.Expected Result:The throttle position on the Cat ET should vary with the turning of the speed adjust potentiometer. The throttle position on the Cat ET should read 0 percent at the lowest setting and 0 to 100 percent as the speed adjust potentiometer is adjusted.The droop on the Cat ET should vary with the turning of the droop adjust potentiometer. The droop on the Cat ET should read 0 percent at the lowest setting and 0 to 10 percent as the droop adjust potentiometer is adjusted.Results:
OK - Rated Speed, Droop Speed - The rated speed and the droop speed are correct. The throttle position on the Cat ET varies with the turning of the speed adjust potentiometer. The droop on the Cat ET varies with the turning of the droop adjust potentiometer.Repair: The circuit is working properly. If the problem is intermittent, perform the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - Rated Speed - The throttle position on the Cat ET does not vary with the turning of the Speed Adjust Potentiometer. Proceed to test step 4.
Not OK - Droop Speed - The droop on the Cat ET does not vary with the turning of the droop adjust potentiometer. Proceed to test step 5.Test Step 4. Check the Throttle Signal from the Loadshare Unit.
Remove the wire from terminal 19 at the loadshare unit.
Set the multimeter to "VDC". Press the "Hz" button twice so that the % symbol is displayed.
Place one probe of the multimeter on terminal 19 of the loadshare unit. Place the other probe on the − Battery terminal of the loadshare unit.
Turn the battery disconnect switch to the ON position.
Turn the ECS to the STOP position.
Monitor the output of the percent duty cycle from the loadshare unit on the multimeter. Turn the speed adjust potentiometer from the low setting to the high setting.
Turn the ECS to the OFF/RESET position.
Turn the battery disconnect switch to the OFF position.
Reconnect the wire that was removed from the terminal 19 of the loadshare unit.Expected Result:The duty cycle should be between 4 and 10 percent at the low setting and between 90 and 95 percent at the high setting.Results:
OK - The loadshare unit is supplying the correct signal. Proceed to test