0311366 JOHNSON SCREW

Table 1
Diagnostic Codes Table    
Description    Conditions which Generate this Code    System Response    
42-5 Injector Actuation Valve current below normal     The Electronic Control Module (ECM) detects a current in the circuit for the Injection Actuation Pressure Control Valve (IAPCV) that is below the minimum threshold.
The ECM has been powered for three seconds.     The engine may begin to misfire and/or shutdown. The engine may experience reduced speed (rpm) and/or low power.
The code is logged.    
42-6 Injector Actuation Valve current above normal     The ECM detects a current in the circuit for the IAPCV that is above the maximum threshold.
The ECM has been powered for three seconds.     The engine may begin to misfire and/or shutdown. The engine may experience reduced speed (rpm) and/or low power.
The code is logged.    
164-3 Injector Actuation Pressure voltage above normal     The ECM detects signal voltage that is above normal for one second.
The ECM has been powered for three seconds.     The code is logged.
The value of the parameter is set to a pressure of
12 MPa (1741 psi).    
E164(1) High Injector Actuation Pressure     The ECM detects injection actuation pressure that is above
24 MPa (3481 psi) for one second.
The ECM has been powered for three seconds.     The code is logged.
The fuel limit is set to a predetermined value.    The 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 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 g01394156
Schematic for the injection actuation pressure control valve
Illustration 2 g01408155
Component locations (1) Injection actuation pressure sensor (2) Injection actuation pressure control valveTest Step 1. Check for Active Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the data link connector.
Restore 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.Expected Result:One of the following diagnostic codes is present:
42-5
42-6
164-3
E164(1) Results:
OK - One of the above codes is active. Proceed to Test Step 2.
Not OK - Neither of the above codes are active. There may be a mechanical problem with the high pressure oil system.Repair: If one of the above codes is logged and the engine is not running properly, refer to Troubleshooting, "Symptom Troubleshooting".If the engine is running properly at this time, there may be an intermittent problem in a harness or in an electrical connector that is causing the codes to be logged. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOPTest Step 2. Inspect Electrical Connectors and Wiring
Remove electrical power from the ECM.
Illustration 3 g01408183
ECM (3) J1/P1 connectors (4) J2/P2 connectors
Thoroughly inspect the J1/P1 and thoroughly inspect the J2/P2 ECM connectors. Thoroughly inspect any connectors that are associated with the circuit for the IAPCV. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 4 g01885473
P2 ECM connector (P2-29) IAPCV supply (P2-35) IAPCV return
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the ether injection system.
Check the allen head screw on each ECM connector for the proper torque. Also check the allen head screw on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from the ether injection solenoid to the ECM. Verify that all connections and grounds are tight and free of corrosion.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 - The connectors and wiring appear to be OK. Proceed to Test Step 3.
Not OK - The connectors and/or wiring are 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 the IAPCV connector.
Measure the resistance between terminal 1 (IAPCV supply) and terminal 2 (IAPCV return) on the solenoid.Expected Result:The resistance is between 5 Ohms and 15 Ohms.Results:
OK - The resistance is between 5 Ohms and 15 Ohms. Proceed to Test Step 4.
Not OK - The resistance is not between 5 Ohms and 15 Ohms. The IAPCV is faulty.Repair: Replace the IAPCV.Verify that the repair eliminates the problem.STOPTest Step 4. Check for Shorts in the Harness
Disconnect the J2/P2 ECM connector.
Disconnect the 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 on the J2/P2 ECM connector.
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 on the J2/P2 ECM connector.Expected Result:All of the resistance measurements indicate an open circuit.Results:
OK - All of the resistance measurements indicate an open circuit. Proceed to Test Step 5.
Not OK - A resistance measurement does not indicate an open circuit. 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
Disconnect the J2/P2 connectors.
Disconnect the IAPCV connector.
Create a short circuit between terminal 1 and terminal 2 at the IAPCV connector.
Measure the resistance between terminal locations P2-29 and P2-35 at the ECM connector.
Return all connectors to the original configuration.Expected Result: