LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Pontiac >> 2000 >> Firebird Base, 2D Convertible, Automatic >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 1 (Engine Control System Self-Diagnostics - 5.7L) >> Diagnostic Tests >> DTC P0134: Ho2S Circuit Insufficient Activity - Bank 1, Sensor 1 >> Diagnostic Procedures
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedures

WARNING: This page is about a different variant/trim than selected.
  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD system check, go to next step.
  2. Start and warm engine to normal operating temperature. Increase engine speed to 1200 RPM for 2 minutes. Using scan tool, select ENGINE 1 and note HO2S 1 voltage. If voltage varies from less than 350 mV to greater than 550 mV, go to next step. If voltage does not vary as specified, go to step  4.
  3. Turn ignition on. Using scan tool, read and record FAILURE RECORDS data. Turn ignition off for 15 seconds. Start engine and operate vehicle within conditions noted in FAILURE RECORDS data. Using scan tool, read SPECIFIC DTC. If scan tool indicates DTC P0134 FAILED THIS IGN, go to next step. If scan tool does not indicate DTC P0134 FAILED THIS IGN, see DIAGNOSTIC AIDS .
  4. Turn ignition on, with engine off. Disconnect HO2S 1. Using jumper wires, jumper HO2S 1 high and low signal circuits to ground. Monitor HO2S 1 voltage with scan tool. If voltage is less than 200 mV, go to step  8. If voltage is not less than 200 mV, go to next step.
  5. Remove jumper wire from HO2S 1 low signal circuit. Check voltage between ground and low signal circuit at HO2S 1 harness connector. 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. Disconnect PCM harness connector C1. Check for continuity in HO2S 1 high signal circuit between HO2S 1 and PCM harness connectors. Repair open circuit if continuity is not present. After repairs, go to step  12. If circuit is okay, go to step  10.
  7. Turn ignition off. Disconnect PCM harness connector C1. Check for continuity in HO2S 1 low signal circuit between HO2S 1 and PCM harness connectors. Repair open circuit if continuity is not present. After repairs, go to step  12. If circuit is okay, go to step  10.
  8. Check HO2S 1 circuits for poor connections at HO2S 1 harness connector. Repair as necessary. After repairs, go to step  12. If connections are okay, go to next step.
  9. Replace HO2S 1. After replacing sensor, go to step  12.
  10. Check HO2S 1 circuits for poor connections at PCM. Repair as necessary. After repairs, go to step  12. If connections are okay, go to next step.
  11. Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
  12. Using scan tool, clear DTCs. Start engine and operate vehicle under conditions required to set this DTC. If scan tool indicates this test ran and passed, go to next step. If scan tool does not indicate 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. If no undiagnosed DTCs are displayed, system is okay.
scientia non olet · About LEMON Manuals