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Home >> Suzuki >> 2002 >> Grand Vitara JLX, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0125: Insufficient Coolant Temperature For Closed Loop Operation >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. Check for DTCs P0117, P0118 and P0335. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If DTCs are not set, go to next step. If any DTC is set, go to that test first.
  2. 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 INTERMITTENTS TROUBLE SHOOTING - NO CODES article.
  3. Turn ignition off. Connect scan tool. Start engine and allow it to reach normal operating temperature. If ECT reading is less than 88°F (31°C), go to next step. If ECT reading is 88°F (31°C) or more, go to step  7 .
  4. Turn ignition off. Disconnect ECT sensor connector. Connect a fused jumper wire between ECT sensor harness connector terminals No. 1 (Orange/Black wire) and No. 3 (Gray/Yellow wire). Turn ignition on. If ECT reading is 401°F (205°C), go to step  6 . If ECT reading is not 401°F (205°C), go to next step.
  5. Check for short or open in Orange/Black wire between ECT sensor and ECM (PCM) 26-pin connector C51-3 terminals No. 22. Also check for short or open in Gray/Yellow wire between ECT sensor ECM (PCM) 26-pin connector C51-3 terminals No. 20. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Repair as necessary and go to DTC CONFIRMATION TEST  . If wires are okay, replace ECM (PCM) and go to DTC CONFIRMATION TEST  .
  6. Check ECT sensor operation. See ENGINE COOLANT TEMPERATURE SENSOR in SYSTEM & COMPONENT TESTING article. Replace as necessary and go to DTC CONFIRMATION TEST  . If ECT sensor is okay, go to next step.
  7. Check thermostat operation. If heater takes a long time to become effective, or coolant flows into radiator on cold start, remove thermostat for inspection. Replace as necessary and go to DTC CONFIRMATION TEST  . If thermostat operates properly, replace ECM (PCM) and go to DTC CONFIRMATION TEST  .
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