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Home >> Pontiac >> 2001 >> Firebird Formula, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - 5.7L >> Diagnostic Tests >> DTC P0134: Ho2S Circuit Insufficient Activity - Bank 1, Sensor 1; P0154: Ho2S Circuit Insufficient Activity - Bank 2, Sensor 1 >> Diagnostic Procedures

Diagnostic Procedures

  1. If powertrain diagnostic system check was performed, go to next step. If powertrain diagnostic system check was not performed, go to POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under DIAGNOSTIC SYSTEM TESTS. After performing powertrain diagnostic system check, go to next step.
    NOTE: Before performing next test step, ensure all HO2S are secure in exhaust pipe. A loose sensor can cause DTC to set.
  2. Start engine and run to normal operating temperature. Increase engine speed to 1200 RPM for 2 minutes. Using scan tool, select ENGINE 1 and note suspect HO2S voltage. If voltage varies from less than 350 mV to more than 550 mV, go to next step. If voltage does not vary from less than 350 mV to more than 550 mV, go to step  4.
  3. Turn engine off if necessary. Turn ignition on. Using scan tool, read and record FAILURE RECORDS data. Turn ignition off for at least 30 seconds. Start engine and operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool indicates DTC failed this ignition, go to next step. If scan tool does not indicate DTC failed this ignition, see DIAGNOSTIC AIDS .
  4. Turn engine off if necessary. Turn ignition on. Locate and disconnect suspect HO2S. See Figure. Connect jumper wires between ground and suspect HO2S connector terminal "A" (Tan/White wire for bank 1, sensor 1; Tan wire for bank 2, sensor 1) and terminal "B" (Purple/White wire for bank 1, sensor 1; Purple wire for bank 2, sensor 1). Monitor suspect HO2S voltage with scan tool. If voltage is less than 200 mV, go to step  8. If voltage is more than 200 mV, go to next step.
  5. Remove both jumper wires. Using DVOM, measure voltage between ground and HO2S connector terminal "A" (Tan/White wire for bank 1, sensor 1; Tan wire for bank 2, sensor 1). If voltage is about 5 volts, go to next step. If voltage is not about 5 volts, go to step  7.
  6. Turn ignition off. Locate PCM and disconnect connector C1. See Figure. For bank 1, sensor 1, using DVOM, measure resistance of Purple/White wire between HO2S connector terminal "B" and PCM connector C1 terminal No. 69. See Figure. For bank 2, sensor 1, using DVOM, measure resistance of Purple wire between HO2S connector terminal "B" and PCM connector C1 terminal No. 66. If resistance is more than 5 ohms, repair open circuit. After repairs, go to step  12. If resistance is 5 ohms or less, go to step  10.
  7. Turn ignition off. Locate PCM and disconnect connector C1. See Figure. For bank 1, sensor 1, using DVOM, measure resistance of Tan/White wire between HO2S connector terminal "A" and PCM connector C1 terminal No. 29. See Figure. For bank 2, sensor 1, using DVOM, measure resistance of Tan wire between HO2S connector terminal "A" and PCM connector C1 terminal No. 26. If resistance is more than 5 ohms, repair open circuit. After repairs, go to step  12. If resistance is 5 ohms or less, go to step  10.
  8. Check for poor connections at suspect HO2S connector. Repair as necessary. After repairs, go to step  12. If connections are okay, go to next step.
  9. Replace suspect HO2S. See REMOVAL, OVERHAUL & INSTALLATION - CARS article. After replacing sensor, go to step  12.
  10. Check HO2S circuits for poor connections at PCM connector. Repair as necessary. After repairs, go to step  12. If connections are okay, go to next step.
  11. Replace PCM. See REMOVAL, OVERHAUL & INSTALLATION - CARS article. After replacing PCM, go to next step.
  12. Using scan tool, clear DTCs. Turn ignition off for at least 30 seconds. Start engine and allow it to reach normal operating temperature. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, go to step  2.
  13. Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTCs are displayed, go to applicable DTC test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no undiagnosed DTCs are displayed, system is okay.
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