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Home >> Isuzu >> 2003 >> Axiom Base, 4WD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Emission Systems & Sub-Systems >> Linear Exhaust Gas RECIRCULATION >> Exhaust Gas Recirculation System Check
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Exhaust Gas Recirculation System Check

  1. Check EGR valve for looseness. If EGR valve is loose, tight fasteners as necessary. If no problem is found, go to next step.
  2. Start engine, and run until engine is at normal operating temperature. Connect Tech 2 or equivalent scan tool to Data Link Connector (DLC). DLC is located under small cover on lower left side of instrument panel. On scan tool select MISCELLANEOUS TESTS and then EGR TEST. Using scan tool, command EGR valve 50 percent On. If engine begins to run roughly and loses RPM, testing is complete. If engine does not perform as specified, go to next step.
  3. Turn ignition off. Disconnect EGR valve 5-pin harness connector. Using test light connected to ground, probe EGR valve ignition feed circuit. If test light illuminates, go to step  5 . If test light does not illuminate, go to next step.
  4. Repair open or short to ground in EGR valve ignition feed circuit between PCM and EGR valve. See WIRING DIAGRAMS  . After repair, repeat step  2 .
  5. Remove EGR valve. Check EGR pintle, valve passages and adapter for excessive deposits, obstructions or restrictions. If problem is found, go to next step. If no problem is found, go to step  7 .
  6. Clean or replace EGR valve or components as necessary. After repair, go to next step.
  7. Holding EGR valve case to ground. Using scan tool, command EGR ON. Observe EGR valve pintle for movement. If EGR pintle moves as commanded, go to next step. If EGR pintle does not move as commanded, perform DTC P0404 in appropriate SELF-DIAGNOSTICS article.
  8. Remove EGR inlet and outlet pipes from intake and exhaust manifolds. Check for excessive deposits, obstructions or restrictions. If problem is found, clean or replace EGR valve or components as necessary. After repair, repeat step  2 .
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