Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Cadillac >> 1998 >> Eldorado Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P1154 - Ho2S Transition Time Ratio Bank 2, Sensor 1 Front) >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK , then go to next step.
  2. Using scan tool, check if other DTCs are present. If other DTCs are present, diagnose affected DTC(s) first. If no other DTCs are present, go to next step.
  3. Start engine. Using scan tool, select ENGINE 1 and observe ECT display. Operate engine until temperature reaches 185°F (85°C). Note ENGINE SPEED and BNK 2 SEN 1 display. Operate engine at 1200-2000 RPM for about 2 minutes. After 2 minutes, check if front oxygen sensor voltage rapidly swings from less than .3 volt to greater than .6 volt. If oxygen sensor voltage is swinging as specified, go to next step. If oxygen sensor voltage is not swinging as specified, go to step 5).
  4. With engine at 1200-2000 RPM, note scan tool LOOP STATUS display. If scan tool display reads CLOSED, fault is not present. See DIAGNOSTIC AIDS. If scan tool display does not read CLOSED, go to step 8).
  5. If front oxygen sensor voltage remains between .3-.6 volt longer that it swings out of this range, go to step 8). If voltage does not remain between .3-.6 volt, go to next step.
  6. Check terminal contact at PCM harness connector C2. Repair as necessary. If terminal contact is okay, go to next step.
  7. Check terminal contact at front oxygen sensor connector. Repair as necessary. If harness connector is okay, go to next step.
  8. Replace front oxygen sensor. Check for possible sensor contamination, i.e. leaded fuel, incorrect gasket seal or over rich operation. If failure is caused by an over rich condition, check fuel injection system. See BASIC ENGINE DIAGNOSTIC PROCEDURES article.
scientia non olet · About Mike's Workshop Manuals