VALVE GP-BANK 4 2244937 - Caterpillar

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Typical schematic
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P1 connector for the Electronic Control Module (ECM) (P1-5) Digital return (P1-61) Overspeed verify switch (torque limiter)
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Location of ECM connectors
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Machine interface connector (Terminal 09) Digital return (Terminal 21) Overspeed verify switch (torque limiter)Test Step 1. Inspect Electrical Connectors and Wiring
Turn the breaker for the ECM to the OFF position.
Thoroughly inspect the ECM connectors J1/P1. Inspect all of the other connectors. Refer to Troubleshooting, "Inspecting Electrical Connectors" for the proper procedure for inspecting system wiring.
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 ECM connector (allen head screw) for the proper torque. Refer to Troubleshooting, "Inspecting Electrical Connectors" for details.
Check the harness and the wiring for abrasion and for pinch points.Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness and wiring are free of corrosion, of abrasion, and of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check the Status of the Overspeed Verify Switch 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.
Operate the overspeed verify switch. Observe the status for the overspeed verify switch on Cat ET.Expected Result:The status of the overspeed verify switch reads "ON" with the overspeed verify switch in the ON position. The status of the overspeed verify switch reads "OFF" when the overspeed verify switch is in the OFF position.Results:
OK - The circuit for the overspeed verify switch is operating normally.Repair: If an intermittent condition is suspected, refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - The circuit for the overspeed verify switch is not operating normally. Proceed to Test Step 3.Test Step 3. Check the Overspeed Verify Switch
Remove the wires from the terminals on the overspeed verify switch.
Connect a voltmeter between terminal 2 and terminal 3 on the overspeed verify switch.
Measure the resistance between terminal 2 and terminal 3 on the overspeed verify switch.
Turn the overspeed verify switch to the ON position.
Measure the resistance between terminal 2 and terminal 3 on the overspeed verify switch.Expected Result:The resistance measurement indicates an open circuit with the overspeed verify switch in the OFF position. The resistance measurement indicates a short circuit with the overspeed verify switch in the ON position.Results:
OK - The resistance measurements are OK. The problem is not with the overspeed verify switch. Proceed to Test Step 4.
Not OK - The resistance measurements are not OK. The overspeed verify switch is not operating correctly.Repair: Replace the overspeed verify switch. Verify that the problem is no longer present.STOPTest Step