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Home >> Buick >> 1996 >> Roadmaster Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control Systems - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P0154 - Ho2S Insufficient Activity Bank 2, Sensor 1 >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. After performing OBD system check, go to next step.
  2. Start and warm engine to normal operating temperature. Increase engine speed to greater than 1200 RPM for 2 minutes. Using scan tool, select ENGINE 1 DATA LIST and monitor Bank 2 HO2S 1 voltage. If voltage is varying outside a range of 352-552 mV, go to next step. If voltage is not varying outside a of range of 352-552 mV, go to step 4).
  3. Turn ignition on, with engine off. Using scan tool, review FREEZE FRAME and/or FAILURE RECORDS data and note parameters. Turn ignition off for about 15 seconds. Start engine and operate vehicle within the conditions required for this diagnostic to run, and as close to conditions recorded in FREEZE FRAME/FAILURE RECORDS as possible. Select DTC function, then enter DTC P0154. If scan tool indicates that this test failed this ignition, go to next step. If scan tool did not indicate that this test failed this ignition, see DIAGNOSTIC AIDS.
  4. Turn ignition on, with engine off. Disconnect Bank 2 HO2S 1 harness connector. Jumper sensor signal and ground circuits, on PCM harness connector side. If voltage is less than 200 mV, go to step 8). If voltage is greater than 200 mV, go to next step.
  5. Remove jumper wire. Using DVOM, check voltage between sensor high and heater ground circuit, on PCM harness side. If voltage is greater than 375 mV, go to next step. If voltage is as specified, go to step 7).
  6. Turn ignition off. Disconnect PCM harness connector. Check continuity of Bank 2 HO2S 1 low circuit. Repair as necessary. After repairs, go to step 13). If circuit is okay, go to step 9).
  7. Turn ignition off. Disconnect PCM harness connector. Check continuity of Bank 2 HO2S 1 signal circuit. Repair as necessary. After repairs, go to step 13). If circuit is okay, go to step 10).
  8. Check for poor sensor ground circuit terminal connection at Bank 2 HO2S 1 harness connector. Repair or replace terminal as necessary. After repairs, go to step 13). If terminals are okay, go to step 11).
  9. Check for poor sensor ground terminal connection at PCM harness. Repair or replace terminals as necessary. After repairs, go to step 13). If terminals are okay, go to step 12).
  10. Check for poor signal circuit terminal connection at PCM harness. Repair or replace terminals as necessary. After repairs, go to step 13). If terminals are okay, go to step 12).
  11. Replace Bank 1 HO2S 1 sensor. After replacing oxygen sensor, go to step 13).
  12. Replace PCM. Program replacement PCM using required equipment. After replacing PCM, go to next step.
  13. Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, then enter DTC P0154. Operate vehicle within the 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, repeat step 2).
  14. Using scan tool, select CAPTURE INFO, REVIEW INFO function. If any undiagnosed DTC(s) are displayed, go to applicable DTC test.
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