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Home >> Mitsubishi >> 2001 >> Mirage ES, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0134: Ho2S No Activity Detected (Sensor 1) >> Diagnostic Procedure
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Diagnostic Procedure

NOTE: After repairs, verify repair by driving vehicle according to appropriate monitor drive cycle and check for DTCs. See VERIFYING REPAIRS  .
  1. Disconnect HO2S 4-pin connector. See Figure . Connect Test Harness (MD998464) to front HO2S connector (component side). Using DVOM, check resistance between test harness terminals No. 1 and 3. Resistance should be 4.5-8.0 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace front HO2S. Go to next step.
  2. Start and warm engine until engine coolant temperature is 176°F (80°C) or more. Connect jumper wire between battery positive terminal and test harness terminal No. 1. Connect second jumper wire between battery negative terminal and test harness terminal No. 3. Connect DVOM between test harness terminals No. 2 and 4. While repeatedly racing engine, check front HO2S output voltage. Voltage should be 600-1000 millivolts. If voltage is as specified, go to next step. If voltage is not as specified, replace front HO2S. Go to step  9 .
  3. Check for poor or loose connections at HO2S and B37 (M/T) or B75, B76 (A/T) ECM connectors. Check for open circuits or damaged wirings between HO2S and ECM. Repair as necessary. Go to next step.
  4. Disconnect fuel injector connector. Check resistance between fuel injector 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.
  5. Using stethoscope, check fuel injector operating sound during cranking or at idle. Ensure frequency of operating sound increases as engine RPM increases. If fuel injectors sound okay, go to next step. If no operating sound is heard from a fuel injector, check fuel injector drive circuit. See DTC P0201-P0204: FUEL INJECTOR NO. 1-4 CIRCUIT MALFUNCTION  .
  6. Check fuel injector connectors, A70, A71, A72 and A73. Check ECM connector B40 (M/T) or B77 (A/T) and wiring between ECM and fuel injector connectors. If problem exists, see DTC P0201-P0204: FUEL INJECTOR NO. 1-4 CIRCUIT MALFUNCTION  . If wiring and connectors are okay, perform fuel pressure test. See FUEL PRESSURE under FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article. If fuel pressure is okay, go to next step.
  7. Check intake system for vacuum leaks. If problem exists, repair vacuum leak. repair as necessary, go to step  9 . If problem does not exist, go to next step.
  8. Check for exhaust leaks. If problem does not exist, go to next step. If problem exists, repair exhaust leak. repair as necessary, go to next step.
  9. Reinstall components, using scan tool, clear DTCs. Test drive vehicle according to OBD-II DRIVE CYCLES and check for DTCs. See OTHER MONITOR  under OBD-II DRIVE CYCLES under VERIFYING REPAIRS. Confirm DTC P0201-P0204 do not reset.
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