Code 13: Intake Air Temperature Sensor

1993 Eagle Summit Wagon DL, 1.8 CSECTION Code 13: Intake Air Temperature Sensor
NOTE: On all models, intake air temperature sensor is built into airflow sensor. For code 13 test purposes, the airflow sensor will be referred to as the intake air temperature sensor. For component terminal identification, see AIRFLOW SENSOR under TERMINAL IDENTIFICATION  . For wiring diagrams, see WIRING DIAGRAMS article in this section.
  1. If using scan tester, go to step 3. Disconnect Intake Air Temperature (IAT) sensor connector. Using a thermometer, check engine compartment ambient temperature. Using DVOM, check resistance between specified IAT sensor terminals. See IAT SENSOR TERMINAL ID  table. Resistance should be 6000 ohms at 32°F (0°C), 2700 ohms at 68°F (20°C) or 400 ohms at 176°F (80°C). If resistance is not as specified, replace IAT sensor. If resistance is as specified, go to next step.
    IAT SENSOR TERMINAL ID

    Application Terminals No.
    All Models 5 & 6
  2. Using a hair dryer, warm IAT sensor while monitoring DVOM. Resistance should decrease evenly as temperature rises. If resistance remains unchanged, replace IAT sensor. If resistance changes, go to step 4.
  3. Turn ignition switch to ON or RUN position. Using a thermometer, check engine compartment ambient temperature. Using scan tester, read Intake Air Temperature (IAT) sensor temperature. See IAT SENSOR TEMPERATURE  table. If temperatures are not as specified, replace IAT sensor. If temperatures are as specified, go to next step.
    IAT SENSOR TEMPERATURE

    Ambient Temperature Standard Value
    -4°F (-20°C) -20°C
    32°F (0°C) 0°C
    68°F (20°C) 20°C
    104°F (40°C 40°C
    176°F (80°C) 80°C
  4. Disconnect IAT sensor connector. Using DVOM, check for continuity between chassis ground and specified IAT sensor connector terminal. See IAT SENSOR GROUND CIRCUIT TERMINAL ID  table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
    IAT SENSOR GROUND CIRCUIT TERMINAL ID

    Application Terminal No.
    All Models 5
  5. On all other models, with IAT sensor connector and ECM connector disconnected, check for continuity between specified IAT sensor connector terminal and ECM connector terminal. See IAT TO ECM WIRING HARNESS TERMINAL ID  table. If continuity does not exist, repair wiring harness as necessary. If continuity exists, go to next step.
    IAT TO ECM WIRING HARNESS TERMINAL ID

    Application IAT Connector Terminal No. ECM Connector Terminal No.
    All Models 6 52
  6. Turn ignition switch to ON position. Check voltage between chassis ground and specified IAT sensor connector. See IAT SENSOR CONNECTOR VOLTAGE SUPPLY CIRCUIT TERMINAL ID  table. If voltage is not 4.5-4.9 volts, replace ECM. If voltage is as specified, replace IAT sensor.
    IAT SENSOR CONNECTOR VOLTAGE SUPPLY CIRCUIT TERMINAL ID

    Application Terminal No.
    All Models 6
RENDER: 1.0x

NO RELATED

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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.