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Home >> Isuzu >> 2003 >> Rodeo S, 2.2 D, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 2.2L >> Diagnostic Tests >> DTC P0405: Exhaust Gas RECIRCULATION System - Circuit Low Input >> Diagnostic Procedure
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Diagnostic Procedure

  1. Perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
  2. Turn ignition on. Using scan tool, select EXHAUST GAS RECIRCULATION VALVE CONTROL TEST  under MISCELLANEOUS TESTS. From scan tool, command EGR valve open to 25, 50, 75 and 100 percent while observing actual EGR valve position. If actual EGR valve position follows commanded EGR position, go to step  15 . If EGR actual position is different than EGR commanded position, go to next step.
  3. Turn ignition off. Disconnect EGR valve 5-pin harness connector. EGR valve is located at top rear of engine. Turn ignition on with engine off. Using DVOM, measure voltage between ground and EGR harness connector terminal No. 4 (Gray/Red wire). See WIRING DIAGRAMS  . Voltage reading should be about 5 volts. If voltage reading is as specified, go to next step. If voltage reading is not as specified, go to step  5 .
  4. Turn ignition off. Using fused jumper wire, jumper EGR valve harness connector terminals No. 3 (Yellow/Red wire) and No. 4 (Gray/Red wire). See WIRING DIAGRAMS  . Turn ignition on. On scan tool, observe ACTUAL EGR VALVE POSITION parameter. With jumper wire connected, ACTUAL EGR VALVE POSITION parameter should read 100 percent. If parameter is as specified, go to step  6 . If parameter is not as specified, go to step  7 .
  5. Using a test light connected to battery voltage, probe EGR valve harness connector terminal No. 4 (Gray/Red wire). If test light illuminates, go to step  8 . If test light does not illuminate, go to step  9 .
  6. Check for poor, loose or damaged terminal connections in 5-volt reference circuit (Gray/Red wire) between PCM and EGR valve. See WIRING DIAGRAMS  . Check for poor, loose or damaged terminal connections in signal circuit (Yellow wire) between PCM and EGR valve. If problem is found, repair as necessary. After repairs are complete, go to step  15 . If no problem was found, go to step  10 .
  7. Using test light connected to battery voltage, probe EGR valve harness connector terminal No. 3 (Yellow/Red wire). If test light illuminates, go to step  11 . If test light does not illuminate, go to step  12 .
  8. Check for short to ground in 5-volt reference circuit (Gray/Red wire) between PCM and EGR valve. See WIRING DIAGRAMS  . If problem is found, repair as necessary. After repairs are complete, go to step  15 . If no problem was found, go to step  13 .
  9. Check for an open in 5-volt reference circuit (Gray/Red wire) between PCM and EGR valve. If problem is found, repair as necessary. After repairs are complete, go to step  15 . If no problem was found, go to step  14 .
  10. Replace EGR valve. See appropriate REMOVAL & INSTALLATION article. After repairs are complete, go to step  15 .
  11. Check for short to ground in EGR signal circuit (Yellow/Red wire) between PCM and EGR valve. See WIRING DIAGRAMS  . If problem is found, repair as necessary. After repairs are complete, go to step  15 . If no problem was found, go to step  13 .
  12. Check for an open in EGR signal circuit (Yellow/Red wire) between PCM and EGR valve. See WIRING DIAGRAMS  . If problem is found, repair as necessary. After repairs are complete, go to step  15 . If no problem was found, go to step  14 .
  13. Replace and reprogram PCM. See POWERTRAIN CONTROL MODULE REPLACEMENT  under POWERTRAIN CONTROL MODULE. After repair is complete, go to step  15 .
  14. Check for poor, loose or damaged terminal connections in all PCM harness connectors. If problem is found, repair as necessary. After repair, go to next step. If no problem was found, repeat test starting in step  13 .
  15. Using scan tool, clear DTCs. Start engine and idle at normal operating temperature. Operate vehicle within CODE ENABLE CRITERIA  . If scan tool indicates DTC P0450 RAN AND PASSED, system is okay. After repair is completed, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If scan tool indicates diagnostic did not pass, repeat test starting in step  2 .
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