LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Suzuki >> 1999 >> Swift Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0125: Insufficient Coolant Temperature For Closed Loop Fuel Control
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P0125: Insufficient Coolant Temperature For Closed Loop Fuel Control

  1. 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 retest system. If thermostat operates properly, go to next step.
  2. Drain coolant. Disconnect ECT sensor harness connector and remove sensor from engine. Measure resistance between ECT sensor terminals while immersed in a container of water. Heat water slowly and ensure resistance changes as specified. Go to ENGINE COOLANT TEMPERATURE (ECT) SENSOR under ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING article. If resistance is not as specified, replace ECT sensor. If resistance is as specified, check for high circuit resistance. See WIRING DIAGRAMS article.If wiring and connectors are okay, replace PCM.
scientia non olet · About LEMON Manuals