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Home >> Cadillac >> 1998 >> Seville SLS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P0125 - ECT Excessive Time To Reach Closed Loop >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK , then go to next step.
  2. Turn ignition on. Using scan tool, select FAILURE REC. and note ECT display. If ECT sensor reads -35°F (-37°C) or less, diagnose using DTC P0117 test. If ECT sensor does not read less than -35°F (-37°C), go to next step.
  3. Start and warm engine to normal operating temperature. Using scan tool, select DATA LIST, ENGINE 1 and note ECT display while engine is warming up. If ECT reading is erratic or skipping (rapid changing), go to step 6). If ECT reading is normal, go to next step.
  4. After engine is fully warmed up (about 20 minutes), note ECT display. If ECT reading is less than 185°F (85°C), go to next step. If ECT reading is not less than 185°F (85°C), fault is not present. See DIAGNOSTIC AIDS.
  5. Check ECT sensor ground and signal circuits for high resistance. Repair as necessary. If circuits are okay, repair cooling system.
  6. Check terminal contact at ECT sensor. Repair as necessary. If terminal contact is okay, go to next step.
  7. Replace ECT sensor.
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