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Home >> Lexus >> 2000 >> SC 300 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0110: Intake Air Temperature (IAT) Sensor Circuit >> Diagnosis & Repair

Diagnosis & Repair

  1. Connect scan tool to Data Link Connector (DLC) No. 3. See Figure. Turn ignition on. Turn scan tool on. Using scan tool, monitor IAT sensor temperature. If temperature displayed is same as actual intake air temperature, check IAT sensor and ECM connections. Problem is intermittent.
  2. If temperature displayed is 284°F (140°C) or more, go to step  5. If temperature displayed is -40°F (-40°C), turn ignition off. Disconnect MAF sensor connector. Connect a fused jumper wire between terminals No. 1 (Yellow/Green wire) and No. 2 (Brown wire) at MAF sensor harness connector. Turn ignition on. Using scan tool, monitor IAT sensor temperature.
  3. If temperature displayed is 284°F (140°C) or more, check MAF sensor connector for corrosion, damage or loose terminals. If connector is okay, replace MAF sensor and retest. If temperature displayed is less than 284°F (140°C), turn ignition off. Remove fused jumper wire. Access ECM under front of carpet on passenger side of vehicle. Backprobing, connect fuse jumper wire between terminals No. 22 (Yellow/Green) wire and No. 18 (Brown wire) at ECM E16 connector. See Figure.
  4. If temperature displayed on scan tool is 284°F (140°C) or more, check and repair wiring harness between MAF sensor harness connector and ECM E16 connector. If temperature displayed on scan tool is not 284°F (140°C) or more, replace ECM and retest.
  5. Turn ignition off. Disconnect MAF sensor connector. Turn ignition on. If temperature displayed on scan tool is -40°F (-40°C), replace MAF sensor and retest. If temperature displayed is not -40°F (-40°C), turn ignition off and go to next step.
  6. Access ECM under front of carpet on passenger side of vehicle. Disconnect E16 connector from ECM. Turn ignition on. If the temperature displayed is -40°F (-40°C), locate and repair short in Yellow/Green wire or Brown wire between MAF sensor and ECM E16 connector. If temperature displayed by scan tool is not -40°F (-40°C), replace ECM and retest.
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