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Home >> Chevrolet >> 1998 >> Tracker 4D Utility, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P0111: Intake Air Temperature (IAT) Sensor Performance >> Diagnostic Test

Diagnostic Test

  1. If powertrain OBD system check has been performed, go to next step. If powertrain OBD system check has not been performed, perform powertrain OBD system check. See POWERTRAIN OBD SYSTEM CHECK  .
  2. Connect scan tool to data link connector. Measure actual ambient air temperature. Turn ignition switch to RUN position. If scan tool displays ambient within 10°F (12°C), go to next step. If scan tool does not display ambient air temperature within 10°F (12°C), go to step 4).
    NOTE: When performing step 3), watch IAT sensor parameter on scan tool display. Look for a skip, jump or no movement in IAT value while temperature increases or decreases.
  3. Remove IAT sensor from air cleaner housing, leaving harness connector connected. Wrap a cool, damp rag around sensor to lower sensor temperature while observing scan tool display. Wrap a warm, damp rag around sensor to lower sensor temperature while observing scan tool display. If scan tool reading skipped, jumped or remained constant during test, go to step 9). If scan tool reading did not skip, jump or remain constant during test, check the following and repair as necessary:
    • Connection at IAT sensor.
    • Damaged wiring harness.
    • IAT sensor. See SENSOR RANGE CHARTS article.
  4. Turn ignition switch to LOCK position. Disconnect IAT sensor harness connector. Using a fused jumper wire, connect IAT harness connector terminals. Turn ignition switch to RUN position. If scan tool reading is not 302°F (150°C), go to next step. If scan tool reading is 302°F (150°C), go to step 9).
  5. Turn ignition switch to LOCK position. Disconnect fused jumper wire. Disconnect PCM harness connectors. Measure resistance in Red/Black wire between PCM and IAT sensor harness connectors. If resistance is .5 ohm or less, go to next step. If resistance is greater than .5 ohm, go to step 7).
  6. Measure resistance in brown wire between PCM and IAC sensor harness connectors. If resistance is .5 ohm or less, go to step 10). If resistance is greater than .5 ohm, go to step 8).
  7. Check for short to ground or high resistance in Red/Black wire between PCM and IAT harness connectors. If short or high resistance does not exist, go to step 10). If short or high resistance exists, repair as necessary and go to step 11).
  8. Check for an open or high resistance in Brown wire between PCM and IAT harness connectors. If open or high resistance does not exist, go to step 10). If open or high resistance exists, repair as necessary and go to step 11).
  9. Replace IAT sensor and go to step 11).
  10. Replace PCM and go to next step.
  11. Test drive vehicle under conditions that set the DTC. Check for other DTCs. If DTCs were retrieved, perform appropriate DTC test. If no DTCs were retrieved, system is okay at this time.
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