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Home >> Suzuki >> 2001 >> Vitara JS, 2D Utility, 1.6, Automatic >> 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. 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  5.
  3. Turn ignition off. Disconnect ECT sensor. Use a fused jumper wire, connect ECT sensor harness connector terminals. Turn ignition on and note temperature displayed on scan tool. If temperature displayed is 327°F (164°C), go to next step. If temperature is not 327°F (164°C), check for short or open in Orange/Black wire and Blue/White wire between ECT sensor and PCM 26-pin connector C51-3 terminals No. 2 and No. 23. See WIRING DIAGRAM article. If wires are okay, replace PCM and go to DTC CONFIRMATION TEST .
  4. Check ECT sensor operation. See ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING article. Replace as necessary. If ECT sensor is okay, go to next step.
  5. Check thermostat operation. Thermostat should begin to open at 186.4-193.6°F (85.8-90°C) on 1.6L engine, 175.4-182.6°F (79.7-83.7°C) on 2.0L engine. Thermostat should be completely open at 212°F (100°C) on 1.6L engine, 203°F (95°C) on 2.0L engine. Thermostat valve should lift to more than 51/64" (8 mm). Replace as necessary. If thermostat is okay, replace PCM and go to DTC CONFIRMATION TEST .
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