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Home >> Mitsubishi >> 2001 >> Eclipse GS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0154: Front Heated Oxygen Sensor (Ho2S) Circuit No Activity Detected (Bank 2 Sensor 1) >> Diagnostic Procedure
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Diagnostic Procedure

  1. Check for exhaust leaks. If problem exists, repair exhaust leak, then go to step  11 . If problem does not exist, go to next step.
  2. Check intake system for vacuum leaks. If problem exists, repair vacuum leak, then go to step  11 . If problem does not exist, go to next step.
  3. Disconnect left front HO2S connector. Check left front HO2S connector for loose, damaged or corroded terminals. If problem exists, repair connector, then go to step  11 . If problem does not exist, go to next step.
    NOTE: Manufacturer recommends connecting Test Harness (MD998464) to left front HO2S (component side) for next step. If using test harness, connect jumper wires to appropriate test harness leads.
  4. Start engine and warm up to normal operating temperature. Connect jumper wire between battery positive terminal and left front HO2S connector terminal No. 1 (component side). See Figure . Connect jumper wire between battery negative terminal and left front HO2S connector terminal No. 3 (component side). Connect digital voltmeter between left front HO2S connector terminals No. 2 and 4 (component side). While repeatedly revving engine, measure left front HO2S output voltage. Voltage should be 0.6-1.0 volt. If voltage is as specified, go to next step. If voltage is not as specified, replace left front HO2S, then go to step  11 .
  5. Turn ignition off. Disconnect left bank fuel injector connectors. Check left bank fuel injector connectors for loose, damaged or corroded terminals. If problem exists, repair connector(s), then go to step  11 . If problem does not exist, go to next step.
  6. Measure resistance between each left bank fuel injector connector terminals (component side). Resistance should be 13-16 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace fuel injector, then go to step  11 .
  7. Disconnect ECM connectors C-51 and C-62 or PCM connectors C-52 and C-59. Check ECM connectors C-51 and C-62 or PCM connectors C-52 and C-59 for loose, damaged or corroded terminals. If problem exists, repair connector(s), then go to step  11 . If problem does not exist, go to next step.
  8. Check for damage to White wire between left front HO2S connector terminal No. 4 and ECM connector C-62 terminal No. 71 or PCM connector C-59 terminal No. 71. If problem exists, repair White wire, then go to step  11 . If problem does not exist, go to next step.
  9. Check for open or short in Yellow/Red wire between fuel injector No. 2 connector and ECM connector C-51 terminal No. 9 or PCM connector C-52 terminal No. 9. See Figure and Figure . Check for open or short in Green/Yellow wire between fuel injector No. 4 connector and ECM connector C-51 terminal No. 2 or PCM connector C-52 terminal No. 2. Check for open or short in Light Green wire between fuel injector No. 6 connector and ECM connector C-51 terminal No. 25 or PCM connector C-52 terminal No. 25. If problem exists, repair appropriate wire, then go to step  11 . If problem does not exist, go to next step.
  10. Check fuel pressure. For procedure, see FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article. Fuel pressure should be 39 psi (270 kPa) at idle with fuel pressure regulator vacuum line connected and 47-50 psi (330-350 kPa) at idle with fuel pressure regulator vacuum line disconnected. If fuel pressure is as specified, replace ECM/PCM, then go to next step. If fuel pressure is not as specified, repair fuel pressure problem, then go to next step.
  11. Test drive vehicle following OBD-II drive cycle other monitor pattern. See OTHER MONITOR  under OBD-II DRIVE CYCLES under VERIFYING REPAIRS. Check for DTCs. If DTC P0154 is output, retry diagnostic procedure. If DTC P0154 is not output, inspection is complete.
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