Engine Coolant Temperature Sensor
A malfunction in Engine Coolant Temperature (ECT) sensor circuit can set a Diagnostic Trouble Code (DTC). For testing procedures and specifications, perform appropriate diagnostic test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article. An out-of-calibration ECT sensor may not set a DTC. Use the following procedure to test sensor calibration.
Disconnect ECT sensor harness connector. See COMPONENT LOCATIONS . Using DVOM, measure resistance of ECT sensor at specified temperatures. See SENSOR TEMPERATURE VS RESISTANCE table. Resistance should be high when engine is cold and drop as engine warms. With vehicle sitting overnight, IAT sensor and ECT sensor should have close to the same resistance reading. If resistance is not within specification, replace ECT sensor.
| Temperature - °F (°C) | (1) Ohms | ||
|---|---|---|---|
| 302 (150) | 47 | ||
| 284 (140) | 60 | ||
| 266 (130) | 77 | ||
| 248 (120) | 100 | ||
| 230 (110) | 132 | ||
| 212 (100) | 177 | ||
| 194 (90) | 241 | ||
| 176 (80) | 332 | ||
| 158 (70) | 467 | ||
| 140 (60) | 667 | ||
| 122 (50) | 973 | ||
| 113 (45) | 1188 | ||
| 104 (40) | 1459 | ||
| 95 (35) | 1802 | ||
| 86 (30) | 2238 | ||
| 77 (25) | 2796 | ||
| 68 (20) | 3520 | ||
| 59 (15) | 4450 | ||
| 50 (10) | 5670 | ||
| 41 (5) | 7280 | ||
| 32 (0) | 9420 | ||
| 23 (-5) | 12,300 | ||
| 14 (-10) | 16,180 | ||
| 5 (-15) | 21,450 | ||
| -4 (-20) | 28,680 | ||
| -22 (-30) | 52,700 | ||
| -40 (-40) | 100,700 | ||
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