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Home >> Suzuki >> 2003 >> XL-7 Base, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTCS P0171 Or P0172: Bank 1 Fuel System - Too Lean/Too Rich >> 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 FUEL PRESSURE under FUEL SYSTEM 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-2: 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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