Ipr (Injection Pressure Regulator) - Navistar International DT 466 Diagnostic/Troubleshooting Manual

494 7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS

IPR (Injection Pressure Regulator)

Figure 480 Function diagram for the IPR
The function diagram for the IPR includes the
following:
• IPR
• Engine Oil Temperature (EOT) sensor
• Injection Control Pressure (ICP) sensor
• Manifold Absolute Pressure (MAP) sensor
• Barometric Absolute Pressure (BAP) sensor
• Camshaft Position (CMP) sensor
• Crankshaft Position (CKP) sensor
• Accelerator Position / Idle Validation (APS/IVS)
sensor
• Electronic Control Module (ECM)
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Function
The IPR valve controls oil pressure in the
high-pressure injection control system that actuates
the injectors. The IPR valve consists of a solenoid,
poppet, and a spool valve assembly.
mounted in the body of the high-pressure pump. The
ECM regulates ICP by controlling the ON/OFF time
of the IPR solenoid. An increase or decrease in the
ON/OFF time positions the poppet and spool valve
inside the IPR and maintains pressure in the ICP
system or vents pressure to the oil sump through the
front cover.
NOTE: The engine may not operate with an IPR fault,
depending on the mode of failure.
EGES-270-1
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
The IPR is