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Home >> Jaguar >> 1996 >> XJS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self Diagnostics >> Self-Diagnostic Tests >> DTC P0118: ECT Sensor Input High
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DTC P0118: ECT Sensor Input High

NOTE: After each repair, clear DTCs. See CLEARING CODES/PCM RESET PROCEDURE  under SELF-DIAGNOSTIC SYSTEM. Turn ignition off and then on. Read DTCs to verify repair is complete. For DLC and PCM connector terminal identification, see CONNECTOR IDENTIFICATION  . For wiring diagrams, see WIRING DIAGRAMS  .
  1. Using scan tool, read DTCs. If DTC P0118 is present, go to next step. If DTC P1118 is not present, problem may be intermittent. See the following:
    • For 1995 models, see INTERMITTENTS in TESTS W/O CODES article.
    • For 1996 models, see INTERMITTENTS in TESTS W/O CODES article.
    • For 1997 XJR models, see INTERMITTENTS in TESTS W/O CODES article.
    • For 1997 XJ6 models, see INTERMITTENTS in TESTS W/O CODES article.
  2. Using scan tool, monitor ECT RANGE. Using a thermometer, check coolant temperature. If scan tool reading and thermometer reading agree, go to step  7 . If readings do not agree, go to next step.
  3. Turn ignition off. Disconnect ECT sensor connector. Using DVOM, check Blue/Yellow wire for continuity between ECT sensor harness connector and PCM harness connector. Repair wiring as necessary. If wiring is okay, go to next step.
  4. Check Black/Brown wire (XJR and XJ6) or Black/Gray wire (XJS) for continuity between ECT sensor harness connector and PCM harness connector. Repair wiring as necessary. If wiring is okay, go to next step.
  5. Check if ECT sensor Blue/Yellow wire is shorted to Black/Brown wire (XJR and XJ6) or Black/Gray wire (XJS). Repair wiring as necessary. If wiring is okay, go to next step.
  6. Check if ECT sensor wires are shorted to battery voltage. Repair wiring as necessary. If wiring is okay, go to next step.
  7. Check resistance across ECT sensor connector terminals. Resistance should be 2045 ohms with coolant at 68°F (20°C), 318 ohms at 176°F (80°C), or 142 ohms at 230°F (110°C). If sensor does not test as specified, replace ECT sensor. If sensor tests as specified, go to next step.
  8. Clear DTCs. Turn ignition off and then on. Read DTCs. If DTC P0118 is not present, repair is complete. If DTC P0118 is present, replace PCM.
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