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Home >> Chevrolet >> 2001 >> Camaro Base, 2D Convertible, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics - 3.8L >> Diagnostic Tests >> DTC 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 CHECKS. After performing powertrain diagnostic system check, go to next step.
    2. NOTE: If any DTCs except HO2S DTCs are present, repair those DTCs first. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
  2. Start engine and run to normal operating temperature. Increase engine speed to more than 1200 RPM for 2 minutes. Using scan tool, select ENGINE 1 DATA LIST and monitor suspect HO2S voltage parameter. If voltage reading is varying outside 400-500 mV, go to next step. If voltage reading is not varying outside 400-500 mV, go to step  4.
  3. Operate vehicle within conditions of FREEZE FRAME/FAILURE RECORDS. If scan tool indicates DTC failed this ignition, go to next step. If scan tool does not indicate DTC failed this ignition, go to INTERMITTENT TROUBLE CODE DETERMINATION  under SELF-DIAGNOSTIC SYSTEM.
  4. Check for an exhaust leak, incorrectly installed HO2S or damaged wiring. Repair as necessary. After repairs, go to step  15. If no problems were found, go to next step.
  5. Turn ignition on. Disconnect HO2S. Connect jumper wire between ground and PCM connector C2 (terminal No. 12 on Bank 1, Sensor 1; terminal No. 10 on Bank 2, Sensor 1; terminal No. 11 on Bank 1, Sensor 2). Using a scan tool, observe HO2S voltage parameter. If scan tool indicates HO2S voltage is more than 400 mV, go to next step. If scan tool indicates HO2S voltage is 400 mV or less, go to step  10.
  6. Remove jumper wire. Using a DVOM, measure voltage between ground and PCM connector C2 (terminal No. 12 on Bank 1, Sensor 1; terminal No. 10 on Bank 2, Sensor 1; terminal No. 11 on Bank 1, Sensor 2). If voltage reading is about 4.5 volts, go to next step. If voltage reading is not about 4.5 volts, go to step  9.
  7. Using a DVOM, measure voltage between ground and PCM connector C1 (terminal No. 27 on Bank 1, Sensor 1; terminal No. 29 on Bank 2, Sensor 1; terminal No. 28 on Bank 1, Sensor 2). If voltage reading is about 5 volts, go to step  11. If voltage reading is not about 5 volts, go to next step.
  8. Using a DVOM, check wiring between PCM connector C1 (terminal No. 27 on Bank 1, Sensor 1; terminal No. 29 on Bank 2, Sensor 1; terminal No. 28 on Bank 1, Sensor 2) and HO2S connector terminal "A" (Tan/White wire on Bank 1, Sensor 1; Tan wire on Bank 2, Sensor 1; Gray wire on Bank 1, Sensor 2) for an open or high resistance. After repairs, go to step  15. If no problem is found, go to step  13.
  9. Using a DVOM, check wiring between PCM connector C2 (terminal No. 12 on Bank 1, Sensor 1; terminal No. 10 on Bank 2, Sensor 1; terminal No. 11 on Bank 1, Sensor 2) and HO2S connector terminal "B" (Purple/White wire on Bank 1, Sensor 1; Purple wire on Bank 2, Sensor 1; Dark Blue wire on Bank 1, Sensor 2) for an open or high resistance. After repairs, go to step  15. If no problem is found, go to step  13.
  10. Using a DVOM, check wiring to HO2S connector terminal "A" (Tan/White wire on Bank 1, Sensor 1; Tan wire on Bank 2, Sensor 1; Gray wire on Bank 1, Sensor 2) for a short to ground. After repairs, go to step  15. If no problem is found, go to step  14.
  11. Check for poor connections at HO2S. After repairs, go to step  15. If no problem is found, go to next step.
  12. Determine cause of HO2S contamination before replacing sensor. Check for fuel contamination, excessive engine oil or coolant consumption, use of an inappropriate RTV sealant (not oxygen sensor safe). Remove HO2S and visually inspect portion of HO2S exposed to exhaust stream in order to check for contamination. If contaminated, portion of HO2S exposed to exhaust stream will have a White powdery coating. Silicone contamination causes a high but false HO2S signal voltage (rich exhaust indication). PCM will then reduce amount of fuel delivered to engine, causing a severe driveability problem. Eliminate source of contamination before replacing the oxygen sensor. Replace affected HO2S sensor. After repairs, go to step  15.
  13. Inspect for poor connections at PCM. Repair as necessary. After repairs, go to step  15. If no problems were found, go to next step.
  14. Replace PCM. After repairs, go to next step.
  15. Using scan tool, clear DTCs. Turn ignition off for 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.
  16. 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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