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Home >> Toyota >> 1997 >> Tercel 2D Sedan, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Tests W/Codes >> Circuit Tests >> DTC P0125: Insufficient Coolant Temperature For Closed Loop Fuel Control >> Diagnosis & Repair
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Diagnosis & Repair

  1. Connect scan tool to DLC No. 3 connector. See Figure. Start vehicle and warm engine to normal operating temperature. Using scan tool, monitor sensor No. 1. Snap accelerate engine 3 times. Sensors should indicate a rich signal (.45 volt or more) at least once.
  2. If a rich signal is indicated at least once, replace ECM and retest. If sensor does not display a rich signal at least once, check for open or short circuit in wiring harness between ECM and suspect sensor. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair wiring as necessary. If wiring harness is okay, replace heated oxygen sensor and retest.
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