Note. This test is associated with DTC P0116 - ECT Sensor Circuit Range, P0117 - ECT Sensor Circuit Low Input and P0118 - ECT Sensor Circuit High Input.
- Install scan tool. Start engine and check if DTC P0116, P0117 or P0118 is present. If DTC is present, go to next step. If DTC is not present, problem is intermittent. See INTERMITTENTS in «TESTS W/O CODES»(ref-16665) article.
- Turn ignition off. Disconnect ECT sensor harness connector. Turn ignition on. Using DVOM, check voltage between ECT sensor harness connector terminal No. 2 and ground. See appropriate wiring diagram in «WIRING DIAGRAMS»(ref-16650) article. Voltage reading should be 4.6-4.8 volts. If voltage is as specified, go to next step. If voltage is not as specified, repair circuit between sensor and ECM.
- Turn ignition off. Check continuity between sensor harness connector terminal No. 1 and ground. If continuity is present, go to next step. If continuity is not present, check circuit between sensor and ECM harness connector.
- Remove ECT sensor from intake manifold. Check ECT sensor resistance while immersing sensor bulb in hot water. See ECT SENSOR TEMPERATURE-TO-RESISTANCE VALUES table. If resistance is not as specified, replace ECT sensor. If resistance is as specified, go to next step.
- Reconnect ECT harness connector. Check cooling system, including thermostat operation. Replace thermostat as necessary. If cooling system is okay, clear DTC. See CLEARING CODES under Self Diagnostic System section. Retest system. If DTC resets, replace ECM.
| Temperature °F (°C) | Ohms |
|---|---|
| 22 (-30) | 22,220-31,780 |
| 14 (-10) | 8160-10,740 |
| 32 (0) | 5180-6600 |
| 68 (20) | 2270-2730 |
| 104 (40) | 1059-1281 |
| 140 (60) | 538-650 |
| 176 (80) | 298-322 |
| 194 (90) | 219-243 |
ECT SENSOR TEMPERATURE-TO-RESISTANCE VALUES