DRIVE GP-FINAL 1913234 - Caterpillar

System Operation Description:The injection actuation pressure control valve (IAPCV) regulates the high pressure oil system that drives the Hydraulic Electronic Unit Injectors (HEUI). The injection actuation pressure sensor monitors the pressure of the high pressure oil system. The Electronic Control Module (ECM) adjusts the pulse width modulated signal to the IAPCV in order to regulate the injection pressure. The IAPCV operates on a signal between 0 and 800 mA.The ECM uses the following criteria in order to determine the desired injection actuation pressure:
Fuel quality
Injection timing
Engine speed (rpm)
Engine operating mode (cold mode, etc.)
Illustration 1 g00676128
Schematic
Illustration 2 g00888260
P2 ECM connectorTest Step 1. Check for Active Diagnostic Codes
Connect the Caterpillar Electronic Technician (ET) to the data link connector.
Start the engine.
Check for active diagnostic codes.Expected Result:One of the following diagnostic codes is present:
42-05 Injection Actuation Valve open circuit
42-06 Injection Actuation Valve short to groundResults:
OK - Proceed to Test Step 2.
Not OK - There may be a mechanical problem with the high pressure oil system.Repair: Repair the problem. Refer to the appropriate topic in the "Troubleshooting Without A Diagnostic Code" section of this manual.Verify that the repair eliminates the problem.STOPTest Step 2. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect the J2/P2 ECM connector and J46/P46 IAPCV connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.Expected Result:All connectors, pins, and sockets are completely inserted and coupled. The harness and wiring are free of corrosion, of abrasions, and of pinch points. All connections and grounds are tight and free of corrosion.Results:
OK - Proceed to Test Step 3.
Not OK - Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 3. Check the Solenoid for an Internal Open or Short
Disconnect J46/P46 IAPCV connector.
Measure the resistance between J46:1 (IAPCV Supply) and J46:2 (IAPCV Return).Expected Result:The resistance is between 5.0 Ohms and 15.0 Ohms.Results:
OK - Proceed to Test Step 4.
Not OK - The IAPCV is faulty.Repair: Replace the IAPCV.Verify that the repair eliminates the problem.STOPTest Step 4. Check for Shorts in the Harness from the IAPCV to the ECM
Disconnect the J2/P2 ECM connector.
Disconnect J46/P46 IAPCV connector.
Measure the resistance between P2:29 (IAPCV Supply) and engine ground. Also, measure the resistance between P2:29 (IAPCV Supply) and all the other pins.
Measure the resistance between P2:35 (IAPCV Return) and engine ground. Also, measure the resistance between P2:35 (IAPCV Return) and all the other pins.Expected Result:The resistance for each measurement is greater than 20,000 Ohms.Results:
OK - Proceed to Test Step 5.
Not OK - There is a short in the wiring between the ECM and the IAPCV.Repair: Repair the circuit.Verify that the repair eliminates the problem.STOPTest Step 5. Check for Open Circuits in the Harness from the IAPCV to the ECM
Turn the keyswitch to the OFF position and install a 7X-1715 Adapter Cable (40-PIN BREAKOUT) at the J2/P2 ECM connector.
Use a suitable piece of wire to short P2:29 (IAPCV Supply) and P2:35 (IAPCV Return).
Disconnect the J46/P46 IAPCV connector.
Measure the resistance between P46:1 (IAPCV Supply) and P46:2 (IAPCV Return).Expected Result:The resistance is less than 10 Ohms.Results:
OK - Proceed to Test