International DT466E Diagnostics (1996–2003)

International 4000-series trucks and IC school buses with the HEUI DT466E: a high-pressure oil pump and IPR valve fire the injectors, a camshaft position sensor, an intake air heater and no EGR, DPF or DEF. Navistar three-digit DTCs (flash codes), not OBD-II P-codes.

Common symptoms

• Engine Stalls or Dies — International DT466E The engine shuts off while driving or at idle and may restart after a short wait. On the International DT466E this symptom usually points to a loss of engine…
• Hard Start or No Start — International DT466E DT466E hard start or no start guide for International DT466E (1996–2003).
• Loss of Power — International DT466E Diagnostic guide for loss of power on International DT466E (1996–2003) HEUI engines. Covers injection control pressure, boost/MAP sensor and accelerator pedal…
• Low Oil Pressure Warning — International DT466E A low oil pressure warning on a 1996–2003 International DT466E can be real low oil pressure or a sensor-circuit fault. The ECM can warn, derate or shut down…
• Overheating — International DT466E Diagnostic guide for International DT466E (1996-2003) overheating symptoms, including high coolant temperature warnings and engine protection responses.
• Rough Running or Misfire — International DT466E A DT466E that runs rough or misfires usually shows a single-cylinder contribution problem or unstable injection control pressure affecting all cylinders.

• DTC 112 — Electrical System B+ Voltage Out of Range – High — International DT466E DTC 112 on the International DT466E (1996–2003) indicates the ECM is seeing battery voltage above its valid range. The code is a Navistar three-digit flash…
• DTC 113 — Electrical System B+ Voltage Out of Range – Low — International DT466E DTC 113 on International DT466E (1996–2003) indicates the ECM is seeing battery voltage below its valid range. Low B+ can affect injector drive and starting…
• DTC 114 — Engine Coolant Temperature Signal Out of Range – Low — International DT466E DTC 114 on International DT466E (1996–2003) indicates the ECM sees an ECT sensor signal voltage below its valid range. The code is a Navistar three-digit flash…
• DTC 115 — Engine Coolant Temperature Signal Out of Range – High — International DT466E Navistar three-digit code for the DT466E indicating the ECM sees an ECT signal voltage above its valid range. The code is a sensor/circuit fault, not a true…
• DTC 121 — Intake Manifold Absolute Pressure Signal Out of Range – High — International DT466E Diagnostic guide for International DT466E (1996–2003) Navistar three-digit code 121.
• DTC 122 — Intake Manifold Absolute Pressure Signal Out of Range – Low — International DT466E DTC 122 on International DT466E (1996–2003) indicates the MAP/boost sensor signal voltage is below its valid range. The engine may run with low power.…
• DTC 124 — Injection Control Pressure Signal Out of Range – Low — International DT466E DTC 124 on the International DT466E (1996–2003) is a Navistar three-digit flash code for the HEUI injection system. It indicates the ECM is seeing an ICP…
• DTC 125 — Injection Control Pressure Signal Out of Range – High — International DT466E Navistar three-digit code for the International DT466E (1996–2003) HEUI engine. The ECM sees the ICP sensor voltage above its valid range. Diagnose the ICP…
• DTC 131 — Accelerator Pedal Position Signal Out of Range – Low — International DT466E Diagnostic reference for Navistar three-digit code 131 on International DT466E (1996–2003).
• DTC 132 — Accelerator Pedal Position Signal Out of Range – High — International DT466E Diagnostic guide for International DT466E (1996–2003) Navistar three-digit code 132.
• DTC 134 — Accelerator Pedal Position and Idle Validation Switch Disagree — International DT466E DTC 134 on International DT466E (1996–2003) indicates the ECM sees a mismatch between the accelerator pedal position sensor signal and the idle validation…
• DTC 143 — Incorrect Number of CMP Signal Transitions Per Cam Revolution — International DT466E DTC 143 on International DT466E (1996–2003) indicates the ECM is not seeing the expected camshaft position (CMP) signal pattern. CMP faults (DTC 143–145) can…
• DTC 144 — CMP Signal Noise Detected — International DT466E The ECM detected electrical noise on the camshaft position (CMP) signal. On the International DT466E (1996–2003) this is a Navistar three-digit flash code…
• DTC 145 — CMP Signal Inactive While ICP Has Increased — International DT466E Navistar three-digit code for the International DT466E (1996–2003) HEUI engine. The ECM saw injection control pressure rise during cranking but did not receive…
• DTC 151 — Barometric Pressure Signal Out of Range – High — International DT466E Barometric pressure signal out of range high on International DT466E (1996–2003).
• DTC 155 — Intake Air Temperature Signal Out of Range – High — International DT466E Diagnostic reference for International DT466E (1996–2003) Navistar three-digit code 155.
• DTC 211 — Engine Oil Pressure Signal Out of Range – Low — International DT466E Navistar three-digit code for the International DT466E (1996–2003). The ECM sees the engine oil pressure (EOP) sensor signal voltage below its valid range.…
• DTC 212 — Engine Oil Pressure Signal Out of Range – High — International DT466E DTC 212 on International DT466E (1996–2003) indicates the engine oil pressure sensor signal voltage is above its valid range. This is a sensor-circuit fault…
• DTC 241 — Injection Control Pressure Regulator OCC Self Test Failed — International DT466E DTC 241 on International DT466E (1996–2003) indicates the ECM’s output circuit check for the injection pressure regulator (IPR) failed. The code is a Navistar…
• DTC 311 — Engine Oil Temperature Signal Out of Range – Low — International DT466E Navistar three-digit DTC 311 on International DT466E (1996–2003) indicates the engine oil temperature sensor signal is below the valid range. The code is a…
• DTC 312 — Engine Oil Temperature Signal Out of Range – High — International DT466E DTC 312 on International DT466E (1996–2003) indicates the engine oil temperature sensor signal voltage is above its valid range. The ECM uses EOT for…
• DTC 313 — Engine Oil Pressure Below Warning Level — International DT466E Engine oil pressure has dropped below the warning threshold on the International DT466E (1996–2003). The ECM can warn, derate or shut down for low oil pressure…
• DTC 314 — Engine Oil Pressure Below Critical Level — International DT466E DTC 314 on International DT466E (1996–2003) indicates engine oil pressure has dropped below the critical level and the ECM may be programmed to shut down for…
• DTC 321 — Engine Coolant Temperature Above Warning Level — International DT466E Diagnostic reference for Navistar DTC 321 on International DT466E (1996–2003).
• DTC 322 — Engine Coolant Temperature Above Critical Level — International DT466E Diagnostic guide for International DT466E (1996–2003) Navistar three-digit code 322.
• DTC 323 — Engine Coolant Level Below Warning / Critical Level — International DT466E DTC 323 on International DT466E (1996–2003) indicates the coolant level sensor reports low coolant. The ECM may warn, derate or shut down depending on…
• DTC 331 — Injection Control Pressure Above System Working Range — International DT466E DTC 331 on International DT466E (1996–2003) indicates the ECM has seen injection control pressure above the normal working range. The code is a Navistar…
• DTC 332 — Injection Control Pressure Above Spec With Engine Off — International DT466E DTC 332 on International DT466E (1996–2003) indicates the ICP sensor reports pressure when the engine is off. The code is a Navistar three-digit flash code…
• DTC 333 — Injection Control Pressure Above / Below Desired Level — International DT466E Diagnostic guide for Navistar DTC 333 on International DT466E (1996–2003).
• DTC 334 — ICP Unable to Achieve Set Point in Time (Poor Performance) — International DT466E Diagnostic reference for Navistar three-digit code 334 on International DT466E (1996–2003).
• DTC 335 — ICP Unable to Build Pressure During Cranking — International DT466E Diagnostic reference for International DT466E (1996–2003) Navistar three-digit code 335.
• DTC 421 — Cylinder 1 – High Side to Low Side Open — International DT466E Diagnostic reference for International DT466E (1996–2003) Navistar three-digit code 421. Focus on injector circuit diagnosis for cylinder 1 high-side to…
• DTC 461 — Cylinder 1 – Cylinder Contribution Test Failed — International DT466E Diagnostic guide for International DT466E (1996–2003) Navistar three-digit code 461.
• DTC 525 — Injector Driver Circuit — International DT466E DTC 525 on International DT466E (1996–2003) indicates the ECM detected a fault in the injector driver circuitry. The HEUI system uses six unit injectors fired…