Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Cadillac >> 1996 >> Seville SLS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P0134 - Ho2S Insufficient Activity Bank 1, Sensor 1 >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) System Check. After performing OBD system check, go to next step.
  2. Start and warm engine until coolant temperature reaches about 185°F (85°C) or greater. Using scan tool, select ENGINE 1 and note bank 1 sensor 1 voltage display for 30 seconds. If voltage remains between .3 and .6 volt, go to next step. If voltage does not remain between .3 and .6 volt, go to step 6).
  3. Turn ignition off. Disconnect rear HO2S harness connector. Start engine. Using DVOM, check voltage between HO2S harness connector terminals "A" and "B". If voltage remains between .3 and .6 volt, diagnose using DTC P0133 test. If voltage does not remain between .3 and .6 volt, go to next step.
  4. Store fluid life index as indicated on scan tool. Turn ignition off for 30 seconds, then disconnect PCM harness connector C2. Using DVOM, check resistance between HO2S high signal circuit at PCM connector and HO2S harness connector terminal "B". If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, go to step 9).
  5. Check resistance between PCM connector C2 HO2S low signal circuit and HO2S harness connector terminal "A". If resistance is 5 ohms or less, go to next step. If resistance is 5 ohms or greater, go to step 10).
  6. Turn ignition on, with engine off. Check voltage between HO2S harness connector terminals "C" and "D". Voltage reading should be 10.5 volts. If voltage is greater than 10.5 volts, go to next step. If voltage is less than 10.5 volts, go to step 8).
  7. Using a jumper wire, jumper HO2S harness connector terminals "C" and "D". Set DVOM to amp scale. Connect DVOM in series between HO2S terminals "D" to "D" (harness to sensor). DVOM should read 0.9-1.5 amps. If reading is as specified, go to step 14). If reading is not as specified, go to step 13).
  8. Check voltage between oxygen sensor harness connector terminal "D" to ground. If reading is 10.5 volts or greater, go to step 11). If reading is less than 10.5 volts, go to next step.
  9. Repair open in HO2S high signal circuit.
  10. Repair open in HO2S low signal circuit.
  11. Repair open in HO2S ground circuit.
  12. Repair open or short to ground in HO2S ignition circuit.
  13. Replace HO2S.
  14. Check terminal contacts at PCM connector C2. Repair as necessary. If terminal contacts are okay, go to next step.
  15. Replace PCM. Program replacement PCM using required equipment.
scientia non olet · About Mike's Workshop Manuals