CONTROL GP-HYDRAULIC 1233277 - Caterpillar

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Typical schematic
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P1 ECM connector (P1-05) Digital return (P1-10) Primary throttle
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Machine interface connector (Terminal 09) Digital return (Terminal 10) Primary throttle
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Location of ECM connectorsTest Step 1. Inspect Electrical Connectors and Wiring
Turn the switch that provides power to the keyswitch input for the ECM to the OFF position.
Turn the breaker for the ECM to the OFF position.
Thoroughly inspect the ECM connector J1/P1. Inspect all of the Connectors in the circuit. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Check the ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the harness and the wiring for abrasion and pinch points.Expected Result:The components and wiring are free of the following problems: damage, corrosion, abrasion and incorrect attachment.Results:
OK - The wiring and connectors are OK. Proceed to Test Step 2.
Not OK - The wiring and/or connectors need repair.Repair: Repair the connectors or wiring and/or replace the connectors or wiring.STOPTest Step 2. Check the Voltage at the Speed Control
Connect the red probe of the digital multimeter to the +Battery terminal of the speed control. Connect the black probe of the digital multimeter to the −Battery terminal of the speed control.Expected Result:The digital multimeter reads 24 3 VDC.Results:
OK - The voltage supply to the speed control is correct. Proceed to Test Step 3.
Not OK - The digital multimeter did not read 24 3 VDC.Repair: There is a problem with the supply voltage to the speed control. Verify that any circuit protection is not tripped. Repair any wiring or connections that are damaged.STOPTest Step 3. Check the Throttle Position on Caterpillar Electronic Technician (ET)
Connect Cat ET to the service tool connector.
Turn the breaker for the ECM to the ON position.
Turn the switch that provides power to the keyswitch input for the ECM to the ON position.
Observe the position of the throttle on Cat ET.
Turn the speed adjust potentiometer to the lowest setting.
Start at the low idle position. Slowly turn the speed adjust potentiometer in the other direction. Monitor the position of the throttle on Cat ET.Expected Result:The throttle position on Cat ET reads 0 percent at the lowest setting and 0 to 100 percent as the speed adjust potentiometer is adjusted.Results:
OK - The speed control is operating correctly.Repair: There may be an intermittent problem. If the problem is intermittent, refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - The throttle position on Cat ET does not respond to adjusting the speed adjust potentiometer. Proceed to Test Step 4.Test Step 4. Check the Speed Control
Remove the wire from the S terminal at the speed control.
Set the multimeter to "VDC". Press the "Hz" button twice so that the % symbol is displayed.
Place one probe of the multimeter on the S terminal of the speed control. Place the other probe on the −Battery terminal of the speed control.
Monitor the output of the percent duty cycle