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Home >> Suzuki >> 2002 >> Esteem GL, 4D Sedan, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 1.8L >> 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. If no other DTC is set, go to next step.
  3. Check intake system for false air leaks. Also, check exhaust systems for leaks. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST  . If no problem is found, go to next step.
  4. Check fuel pressure. See FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article. If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, go to FUEL PRESSURE TEST under SYSTEM TESTS in BASIC DIAGNOSTIC PROCEDURES article. If no problem is found, go to next step.
  5. Inspect fuel injectors and fuel system circuit. Go to, FUEL SYSTEM in SYSTEM & COMPONENT TESTING article. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST  . If fuel injectors and fuel system circuit is okay, go to next step.
  6. Check fuel level sensor. For testing procedure, go to DTC P0461: FUEL LEVEL SENSOR CIRCUIT - PERFORMANCE PROBLEM  . If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST  . If no problem is found, go to next step.
  7. Check MAF sensor operation. For testing procedure, go to DTC P0101: MASS AIR FLOW SENSOR - PERFORMANCE PROBLEM  . If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST  . If MAF sensor is okay, go to next step.
  8. Check ECT sensor operation. See appropriate procedure under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING article. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST  . If ECT sensor operation is okay, go to next step.
  9. Check HO2S No. 1 operation. For testing procedure, go to DTC P0131 OR P0132  . If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST  . If HO2S No. 1 operation 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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