Engine Coolant Temperature (ECT) Sensor
If a coolant sensor-related code is present, see appropriate TESTS W/CODES - 4.3L article in this section. An out-of-calibration sensor may not set a trouble code. Use following procedure to test sensor calibration. Disconnect ECT sensor connector. Measure resistance between sensor terminals. Resistance should be high when engine is cold and drop as engine warms. See ECT SENSOR RESISTANCE VALUES table.
ECT SENSOR RESISTANCE VALUES
| Temperature: °F (°C) | Ohms |
|---|---|
| 212 (100) | 177 |
| 158 (70) | 467 |
| 100 (38) | 1800 |
| 68 (20) | 3520 |
| 23 (-5) | 12,300 |
| 0 (-18) | 25,000 |
| -40 (-40) | 100,700 |
NOTE:
Intake Air Temperature (IAT) sensor is also referred to as Manifold Air Temperature (MAT) sensor.