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Home >> Suzuki >> 2002 >> XL-7 Plus >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0171 Or DTC P0172 >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. If engine system check has been performed, go to next step. If engine system check has not been performed, go to A4: ENGINE SYSTEM CHECK  under SYSTEM TESTS.
  2. Using scan tool, check for current or pending DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES . If DTCs other than DTC P0171 or P0172 is set, repair those DTCs first. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no other DTC is set, go to next step.
  3. Inspect intake and exhaust systems for leaks. If any leaks are detected, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If intake and exhaust systems are okay, go to next step.
  4. Check fuel pressure. See B-3: FUEL PRESSURE INSPECTION under CIRCUIT TESTS in BASIC DIAGNOSTIC PROCEDURES article. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If fuel pressure is within specifications, go to next step.
  5. Check fuel injector operation. See B-1: FUEL INJECTOR CIRCUIT INSPECTION under CIRCUIT TESTS in BASIC DIAGNOSTIC PROCEDURES article. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If fuel injectors are okay, go to next step.
  6. Check fuel lever sensor operation. See DTC P0461 . If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If fuel level sensor is okay, go to next step.
  7. Check MAF sensor circuit operation. See DTC P0101 . If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If MAF sensor circuit is okay, go to next step.
  8. Check ECT sensor circuit operation. See DTC P0125 . If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If ECT sensor circuit is okay, go to next step.
  9. Check HO2S No. 1 sensor circuit operation. See DTC P0131 OR DTC P0132  test. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST . If HO2S No. 1 sensor circuit is okay, go to next step.
  10. Substitute a known good ECM, and repeat DTC CONFIRMATION TEST . If DTC does not reset, testing is complete.
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