VALVE GP-CONTROL 1879337 - Caterpillar

a 45 N (10 lb) pull test on each of the wires that are associated with the engine pressure sensors.
Check the torque of the allen head screws for the ECM connectors. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Check the harness and wiring for abrasions and for pinch points from each sensor back to the ECM. 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 wiring and/or the connectors.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the problem is resolved.STOPTest Step 2. Check the Voltage on the +5 V Supply Wire
Remove the electrical power from the ECM.
Disconnect the harness connectors for the following sensors:
Injection actuation pressure sensor
Boost pressure sensor for the intake manifold
Atmospheric pressure sensor
Fuel pressure sensor
Engine oil pressure sensor
Restore the electrical power to the ECM.
Measure the voltage between terminals A (+5 VDC) and B (Return) at each sensor connector on the engine harness.
Remove the electrical power from the ECM.
Connect all of the sensors. Expected Result:Each voltage measurement is 5.0 0.2 VDC.Results:
OK - Each voltage measurement is 5.0 0.2 VDC. Proceed to Test Step 3.
Not OK - At least one voltage measurement is not 5.0 0.20 VDC.Repair: Refer to the diagnostic functional test Troubleshooting, "5 Volt Engine Pressure Sensor Supply Circuit - Test".STOPTest Step 3. Check for Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector. Refer to electronic troubleshooting Troubleshooting, "Electronic Service Tools".
Restore the electrical power to the ECM.
Observe the "Active Diagnostic"