PLATE (7 MM THICK) 0940577 - Caterpillar

System Operation Description:Use this procedure to troubleshoot any suspect problems with the Injection Actuation Pressure Control Valve (IAPCV). Use this procedure if the diagnostic code or the event code in Table 1 is active or easily repeated.
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 IAPCV that is below the minimum threshold.     The engine may begin to misfire and/or shutdown. The engine may experience reduced speed (rpm) and/or low power.
The ECM will trigger a snapshot. 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 engine may begin to misfire and/or shutdown. The engine may experience reduced speed (rpm) and/or low power.
The ECM will trigger a snapshot. The code is logged.    The IAPCV is internal to the unit injector hydraulic pump. The IAPCV is a precision displacement control actuator. This actuator changes the pump outlet flow that is based on the control current that is supplied by the ECM. The variable displacement unit injector hydraulic pump pressurizes only the amount of high pressure oil that is needed.The ECM software contains performance maps. The performance maps have a desired actuation pressure for every engine operating condition. The ECM sends a control current to the IAPCV. This signal creates an actual actuation pressure that matches the desired actuation pressure. If the actual actuation pressure does not match the desired actuation pressure, the ECM will increase the control current or the ECM will decrease the control current to the IAPCV in order to adjust pump outlet flow.The following problems can cause a 5 diagnostic code:
An open circuit in the wiring
An open circuit in the IAPCV
A short to ground on the return wireThe following problems can cause a 6 diagnostic code:
The control wire has a short to the +Battery.
The return wire has a short to the +Battery.
A short circuit in the IAPCV
A short to ground on the control wire
Illustration 1 g01337725
Schematic for the injection actuation pressure control valveTest Step 1. Inspect the Electrical Connectors and the Wiring
Remove the electrical power from the ECM.
Illustration 2 g01339380
Component locations for the IAPCV (Typical left side engine view) (1) Connector for the injection actuation pressure control valve (2) J2/P2 ECM connectors
Thoroughly inspect connectors (1) and (2). Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect".
Illustration 3 g01339387
Terminal locations at the P2 ECM connectors for the IAPCV (P2-10) Return (P2-20) Injection actuation pressure control valve
Illustration 4 g01218763
Terminal locations at the connector for the IAPCV (1) Injection actuation pressure control valve (2) Return
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 each of the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness