RING-PISTON 1154103 - Caterpillar

System Operation Description:Use this procedure to troubleshoot any suspect problems with the Injection Actuation Pressure Control Valve (IAPCV).This procedure covers the following diagnostic codes:
42-05 Injector Actuation Valve open circuit
42-06 Injector Actuation Valve short to groundThe 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 Electronic Control Module (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 05 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 06 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 g01275408
Schematic for the injection actuation pressure control valve
Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove the electrical power from the ECM.
Illustration 2 g01223470
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".
Illustration 3 g01223476
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