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Home >> Jaguar >> 2000 >> XJ8 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Trouble Code Identification >> DTC P0116: Engine Coolant Temperature Sensor Range/Performance >> Diagnostic Test Procedure
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Diagnostic Test Procedure

NOTE: Before performing this procedure, check the coolant level, coolant condition and operation of the thermostat. Repair as necessary.
NOTE: As a guideline, coolant temperature overnight will drop to approximately -4-104°F (-20-40°C), at which the resistance of the sensor should be 15.04-1.15 k/ohms. See IAT & ECT SENSOR RESISTANCE  table.
NOTE: DTC P0116 requires a cold start condition for diagnostics. Ideally, park the vehicle outside overnight. Start the engine and leave the engine idling with the heater on full (this produces the slowest warm-up time). Leave the engine running until normal operating temperature of 176°F (80°C) is reached. Take temperature reading from the Jaguar approved diagnostic system or scan tool. At normal operating temperature, the sensor resistance should be 320 ohms. See IAT & ECT SENSOR RESISTANCE  table.
  1. Disconnect negative battery cable. Disconnect ECM connectors EM82 and EM83. Disconnect the ECT sensor connector. Measure resistance between ECM harness connector EM82 terminal No. 14 and ECT sensor harness connector terminal No. 2. Is resistance greater than 5 ohms? If yes, repair the high resistance between ECM harness connector EM82 terminal No.14 and ECT sensor harness connector terminal No. 2. If no, go to next step.
  2. Reconnect the negative battery cable. Turn ignition on. Measure the voltage between ECT sensor terminal 2 and ground. Is voltage greater than 3 volts? If yes, repair the short to voltage. If no, go to next step.
  3. Turn ignition off. Measure resistance between ECT sensor harness connector terminal No. 2 and ground. Is resistance less than 10,000 ohms? If yes, repair short to ground. If no, go to next step.
  4. Measure the resistance between the terminals of the ECT sensor. Is resistance within 10 percent of specification? If no, install a new ECT sensor. See IAT & ECT SENSOR RESISTANCE  table. If yes, recheck the DTCs. If DTC resets, possible ECM failure.
IAT & ECT SENSOR RESISTANCE

Temperature °F (°C) Ohms
-4 (-20) 15,000
32 (0) 5740
68 (20) 2450
104 (40) 1150
140 (60) 584
176 (80) 320
212 (100) 184
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