LEMON Manuals: Even more car manuals for everyone
Home >> Isuzu >> 1998 >> Trooper S, Standard >> Repair and Diagnosis (Single Page) >> Engine Performance >> Testing & Diagnosis >> Engine Controls - Tests W/Codes - 3.2L & 3.5L >> Self-Diagnostic Tests >> DTC P1154: Heated Oxygen Sensor (Ho2S) No. 1 Bank 2 Circuit Transition Time Ratio >> Diagnostic Aids

Diagnostic Aids

An intermittent problem can be caused by misrouted harness, rubbed-through wire insulation or broken wire inside insulation of HO2S heater circuit. If connections and wiring are okay and DTC continues to reset, replace HO2S 1. Check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

  1. Perform On-Board Diagnostic (OBD) System Check. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
  2. If any DTC other than P1133 or P1134 sets, diagnose affected DTC before proceeding. If no other DTC sets, start engine and allow it to idle. Operate vehicle within conditions required to set DTC. Using scan tool, read SPECIFIC DTC. If scan tool displays DTC P1154 FAILED THIS IGN, go to next step. If scan tool does not display DTC P1154 FAILED THIS IGN, check for an intermittent problem, see DIAGNOSTIC AIDS  .
  3. If DTC P1133 and/or P1134 is also set, go to step 11). If DTC is not set, go to next step.
  4. Check exhaust system for leaks. If exhaust leak is found, repair as necessary. Retest system. If no exhaust leak is found, go to next step.
  5. Visually inspect HO2S No. 1 for secure installation or corrosion on terminals. Check terminal tension at HO2S No. 1 and PCM. Check for damaged wiring. If a problem is found, go to step 8). If no problem is found, go to next step.
  6. Disconnect HO2S No. 1 connector. Turn ignition on. Using DVOM, probe connector, measure voltage between high signal circuit (White wire - 3.2L, Red wire - 3.5L) and ground, and low signal circuit (Red wire - 3.2L, Green wire - 3.5L) and ground. If DVOM reads 3-4 volts, go to next step. If voltage is not as specified, go to step 9).
  7. Turn ignition off. With HO2S No. 1 disconnected, connect a jumper wire between HO2S No. 1 harness connector high signal (White wire - 3.2L, Red wire - 3.5L), low signal (Red wire - 3.2L, Green wire - 3.5L) and ground. Turn ignition on. If scan tool reading jump from .01 volt to .45 volt when jumper is removed, go to step 11). If voltage does not change as specified, go to step 12).
  8. Repair condition as necessary. Retest system.
  9. Check for poor PCM connections or terminal damage. Repair as necessary. Retest system. If no problem is found, go to next step.
  10. Repair open, grounded or shorted signal circuit. Retest system. If no problem is found, go to step 7).
  11. Remove Bank 2 HO2S No. 1 and check it for fuel contamination, improper RTV sealant (white powdery coating on sensor) and engine oil or coolant consumption. Repair as necessary. Retest system. If no problem is found, go to step 13).
  12. Replace PCM. Retest system.
  13. Replace HO2S No. 1. Retest system.
scientia non olet · About LEMON Manuals