Intake Air Temperature (IAT) Sensor
If an IAT sensor-related code is present, see TESTS W/CODES article. An out-of-calibration sensor may not set a trouble code. Use following procedure to test calibration. Disconnect IAT sensor harness connector. Connect ohmmeter between sensor terminals. Sensor resistance should be as specified. See IAT SENSOR RESISTANCE table. With vehicle sitting overnight, IAT sensor and coolant sensor should have close to the same resistance reading.
IAT SENSOR RESISTANCE
| Temperature °F (°C) | Resistance (Ohms) |
|---|---|
| 210 (100) | 185 |
| 160 (70) | 450 |
| 100 (38) | 1800 |
| 70 (20) | 3400 |
| 40 (4) | 7500 |
| 20 (-7) | 13,500 |
| 0 (-18) | 25,000 |
| -40 (-40) | 100,700 |