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Home >> Suzuki >> 2001 >> Esteem GL, 4D Sedan, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - Esteem 1.8L >> Diagnostic Tests >> DTC P0125: Insufficient Coolant Temperature For Closed Loop Operation >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. Perform DTC CONFIRMATION TEST  . If DTC P0125 is set, go to next step. If DTC P0125 is not set, problem is intermittent. System is okay at this time. See TROUBLE SHOOTING - NO CODES article.
  2. Turn ignition off. Connect scan tool. Start engine and allow it to reach normal operating temperature. Using scan tool, check engine coolant temperature. If engine coolant temperature is less than 88°F (31°C), go to next step. If engine coolant temperature is 88°F (31°C) or more, go to step  6 .
  3. Turn ignition off. Disconnect ECT sensor connector. Connect a fused jumper wire between ECT sensor harness connector terminal No. 1 (Light Green/Red wire) and No. 3 (Orange wire). Turn ignition on. Check coolant temperature on scan tool. If coolant temperature is 401°F (205°C), go to step  5 . If coolant temperature is not 401°F (205°C), go to next step.
  4. Check for short or open in Light Green/Red and Orange wires between ECT sensor connector and ECM 28-pin connector C20 terminals No. 12 and No. 27. See WIRING DIAGRAMS article. If wires are okay, replace ECM and go to DTC CONFIRMATION TEST  .
  5. Drain coolant. Remove ECT sensor from thermostat housing and place in water with a thermometer. Heat water to specified temperature and check resistance. See Figure . Replace ECT sensor as necessary and go to DTC CONFIRMATION TEST  . If resistance is as specified, go to next step.
  6. Check thermostat operation. If heater takes a long time to warm up, or coolant flows into radiator on cold start, remove thermostat for inspection. Replace thermostat as necessary and go to DTC CONFIRMATION TEST  . If thermostat operates properly, replace ECM and go to DTC CONFIRMATION TEST  .
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