Intake Air Temperature (IAT) Sensor
IAT sensor may also be referred to as a Manifold Air Temperature (MAT) sensor. If a IAT sensor related code is present, see TESTS W/CODES article. An out-of-calibration sensor may not set a diagnostic 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 VALUES table. After vehicle has sat overnight, IAT sensor and coolant sensor should have close to the same resistance reading.
IAT SENSOR RESISTANCE VALUES (1)
| Temperature °F (°C) | Ohms | ||
|---|---|---|---|
| 212 (100) | 177 | ||
| 194 (90) | 241 | ||
| 158 (70) | 467 | ||
| 104 (40) | 1459 | ||
| 68 (20) | 3520 | ||
| 23 (-5) | 12,300 | ||
| 14 (-10) | 16,180 | ||
| 0 (-18) | 25,000 | ||
| -4 (-20) | 28,680 | ||
| -22 (-30) | 52,700 | ||
| -40 (-40) | 100,700 | ||
|
|||