SENSOR AS-PRESSURE 4343436 - Caterpillar

System Operation Description:Use this procedure to troubleshoot any suspect problems with the injection actuation pressure sensor.Use this procedure to troubleshoot the 164-02 Injector Actuation Pressure signal erratic that is active.Note: This procedure can check the accuracy of the injection actuation pressure sensor against a pressure gauge.The injection actuation pressure sensor measures the pressure of the oil in the high pressure oil manifold. The high pressure oil in the manifold is used to actuate the injectors and the high pressure oil is used to control the fuel injection pressure. The ECM uses the reading from the injection actuation pressure sensor in order to control the operation of the injection actuation pressure control valve.
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The connection of any electrical equipment and the disconnection of any electrical equipment may cause an explosion hazard which may result in injury or death. Do not connect any electrical equipment or disconnect any electrical equipment in an explosive atmosphere.
Test Step 1. Check for Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the service tool connector. Refer to Troubleshooting, "Electronic Service Tool".
Turn the keyswitch to the ON position.Note:
Observe the "Active Diagnostic" screen on Cat ET. Wait at least 15 seconds so that any codes may become active. Look for an active 164-02 diagnostic code.Note: If a 164-03 Injector Actuation Pressure voltage high or a 164-04 Injector Actuation Pressure voltage low is active, refer to Troubleshooting, "Engine Pressure Sensor Open or Short Circuit - Test".Expected Result:The 164-02 diagnostic code is not active.Results:
OK - No 164-02 diagnostic code is active. Proceed to Test Step 2.
Not OK - A 164-02 diagnostic code is active. Proceed to Test Step 3.Test Step 2. Try to Start the Engine Try to start the engine.Expected Result:The engine starts.Results:
OK - The engine starts. There are no active codes for the injection actuation pressure sensor and the engine starts.Repair: There may be an intermittent problem in a harness that is causing the code to be logged. Refer to Troubleshooting, "Electrical Inspectors - Inspect".STOP
Not OK - The engine does not start.Repair: Refer to Troubleshooting, "Engine Cranks but Will Not Start".STOPTest Step 3. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF position.
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Component locations (typical example) (1) Unit injector hydraulic pump (2) Injection actuation pressure sensor (3) Injection Actuation Pressure Control Valve (IAPCV) (4) High pressure supply line to cylinder head (5) Low pressure supply line to pump (6) ECM (7) J2/P2 ECM connector
Thoroughly inspect the J204/P204 injection actuation pressure sensor connector and the J2/P2 ECM connector. Refer to Troubleshooting, "Electrical Connectors - Inspect".
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P2 terminals that are associated with the injection actuation pressure sensor (P2-3) Return (P2-2) +5 VDC (P2-27) Injection Actuation pressure
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Connectors for the injection actuation pressure sensor (A) Supply (B) Return (C) Signal
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the injection actuation pressure sensor.
Check the allen head screws on the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct