VALVE GP-SELECTOR & PRESS CONT 6Y1291 - Caterpillar

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Typical left side view
(1) J500/P500 connector
(2) J2/P2 connectors
Thoroughly inspect connectors (1) and (2). Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
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P2 terminations for the IAPCV
(P2-10) Return
(P2-20) Control
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the IAPCV.
Check the torque of the allen head screws for the ECM connectors. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and wiring for abrasion and for pinch points from the IAPCV back to the ECM. Note: Ensure that the seal is installed on the harness connector for the injection actuation pressure control valve.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 connectors and the wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or the 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 for Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tools".
Restore the electrical power to the ECM.
Start the engine.
Observe the "Active Diagnostic" screen on Cat ET. Wait at least 30 seconds so that any codes may become active. Look for the code that is 05 or 06. Expected Result:One of the above codes is active.Results:
Active code - One of the above codes is active. Proceed to Test Step 3.
No active codes - Neither of the above codes are active.Repair: If one of the above codes is logged and the engine is not running properly, refer to Troubleshooting, "Troubleshooting without a diagnostic code".If the engine is running properly at this time, there may be an intermittent problem in a harness that is causing the codes to be logged. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".STOPTest Step 3. Measure the Resistance of the Injection Actuation Pressure Control Valve's Solenoid
Remove the electrical power from the ECM.
Disconnect the IAPCV connectors. Note: Ensure that the seal on the P500 connector remains on the connector when the connector is disconnected.
Measure the resistance between terminals 1 (Control) and 2 (Return) on the IAPCV. Record the value of the resistance measurement. Expected Result:The resistance measurement is between 6.5 and 10.5 Ohms.Results:
OK - The resistance measurement is between 6.5 and 10.5 Ohms. Connect the J500/P500 connectors. Proceed to Test Step 4.
Not OK - The resistance measurement is not between 6.5 and 10.5 Ohms. The solenoid's resistance is not within the specification.Repair: Replace the unit injector hydraulic pump. Verify that the problem is resolved.STOPTest Step 4. Check the Wiring for an Open Circuit
Remove the electrical power from the ECM.
Disconnect the J2/P2 connectors.
Measure the resistance between terminals P2-20 (Control) and P2-10 (Return). Expected Result:The resistance measurement is