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Engine Coolant Temperature Sensor Circuit

  1. Turn ignition switch to OFF position. Access Engine Control Module (ECM), located behind right fascia. See Fig 1 . Disconnect ECM connector. Check resistance between ECM harness connector terminals No. 7 (Green/Blue wire) and 25 (Red/Black wire). See Figure . Engine Coolant Temperature (ECT) sensor circuit resistance should be as specified. See FUEL & COOLANT TEMPERATURE SENSOR RESISTANCE  table. If resistance is not as specified, go to next step. If resistance is as specified, ECT sensor circuit is okay.
  2. Check for short or open in Green/Blue wire between ECM terminal No. 7 and ECT sensor. If wire is okay, check for short or open in Red/Black wire between ECM terminal No. 25 and ECT sensor.
FUEL & COOLANT TEMPERATURE SENSOR RESISTANCE

Temperature In °F (°C) Resistance In Ohms
14 (-10) 9100-9300
32 (0) 5700-5900
68 (20) 2400-2600
104 (40) 1100-1300
140 (60) 500-700
176 (80) 300-400
212 (100) 150-200
Fig 1: Locating Engine Control Module
G00273337Courtesy of LAND ROVER NORTH AMERICA, INC.