The IPR valve is supplied with voltage at Pin A of the IPR connector through 12–pin connector (Pin 9) from VIGN. The control of the injection control system is gained by the ECM grounding Pin B of the IPR valve through Pin X1-12 of the ECM. Precise control is gained by varying the percentage of ON/OFF time of the IPR solenoid. A high duty cycle indicates a high amount of injection control pressure is being commanded. A low duty cycle indicates less pressure being commanded.
Fault Detection / Management
An open or short to ground in the ICP control circuit can be detected by an on demand output circuit check during KOEO Standard Test. If there is a circuit fault detected a Diagnostic Trouble Code (DTC) will be set. When the engine is running, the ECM can detect if the injection control pressure is equal to the desired pressure. When the measured injection control pressure does not compare to the desired pressure, the ECM will ignore the measured ICP signal and controls the engine with the desired value.
IPR Diagnostic Trouble Codes (DTCs)
DTCs are read using the EST or by counting the flashes from the amber and red ENGINE lamp.
DTC 241
IPR OCC self-test failed
• DTC 241 is set by the ECM when the Output Circuit Check (OCC) test has failed after the KOEO Standard Test has been run.
• DTC 241 can be set when a poor connection to the IPR solenoid or inoperative IPR coil exists.
• When DTC 241 is active the engine will not run and the amber ENGINE lamp will not be illuminated.
Tools
• EST with MasterDiagnostics® software
• EZ-Tech® interface cable
• Digital Multimeter (DMM)
• Breakout Box
• Actuator Breakout Harness
• Terminal Test Adapter Kit
