SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSISUZU1996TROOPER S, AUTOMATICREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 17 (ENGINE CONTROLS - TESTS W/CODES - 2.6L 4-CYL)CIRCUIT TESTINGDTC P0135 - HO2S HEATER CIRCUIT SENSOR 1DIAGNOSTIC PROCEDURES
1996 Isuzu Trooper S, Automatic

Diagnostic Procedures

1996 Isuzu Trooper S, AutomaticSECTION Diagnostic Procedures
WARNING: This page is about a different car, the 1996 Honda Passport. However, it is still accessible from the selected car via links, so may be relevant.
  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.
    NOTE: If engine has been operating, allow engine to cool for about 30 minutes before proceeding with tests.
  2. Turn ignition on, engine off. Using scan tool, read HO2S 1 voltage. If voltage is greater than 0.65 volt or less than 0.25 volt, see DIAGNOSTIC AIDS . If voltage is not as specified, go to next step.
  3. Inspect HO2S 1 ignition feed fuse. If fuse is open, go to step 15). If fuse is okay, go to next step.
  4. Turn ignition off. Raise and support vehicle. Disconnect HO2S 1 harness connector. Connect a test light between chassis ground andHO2S 1 ignition feed circuit. If test light illuminates, go to next step. If test light does not illuminate, go to step 7).
  5. Connect test light between HO2S 1 harness connector ignition feed and heater ground circuits. If test light illuminates, go to next step. If test light does not illuminate, go to step 8).
  6. Allow HO2S 1 to cool for at least 10 minutes. Using DVOM, check resistance between ignition feed and heater ground circuits at HO2S 1. If resistance is 3-6 ohms, go to step 9). If resistance is not as specified, go to step 10).
  7. Repair open HO2S 1 ignition feed circuit and go to step 16).
  8. Repair open HO2S 1 heater ground circuit and go to step 16).
  9. Check for faulty connection at HO2S 1 harness connector. If faulty connection is found, repair as necessary and go to step 16). If connection is okay, go to next step.
  10. Check for faulty connection at HO2S 1 ground and signal circuit harness connector. If faulty connection is found, repair as necessary and go to step 16). If connection is okay, go to next step.
  11. Turn ignition off. Disconnect PCM connectors. Check resistance of HO2S 1 signal and ground circuits. If resistance on either circuit is greater than 5 ohms, repair open or faulty connection as necessary and go to step 16). If resistance is 5 ohms or less, go to next step.
  12. Check for faulty ground circuit connection at PCM. If faulty connection is found, repair as necessary and go to step 16). If connection is okay, go to next step.
  13. Check for faulty HO2S 1 signal circuit connection at PCM. If faulty connection is found, repair as necessary and go to step 16). If connection is okay, go to next step.
  14. Replace HO2S 1 and go to step 16).
  15. Locate and repair short to ground in HO2S 1 ignition feed circuit, replace fuse and go to next step.
  16. Allow engine to cool completely. Using scan tool, clear DTCs. Turn ignition on, engine off. Read HO2S 1 voltage. If voltage is greater than 0.6 volt or less than 0.3 volt, repair is complete. If voltage is not as specified, return to step 2).
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

Shop Manual-Ready ToolsFree Quote CheckQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.