The diagnostic trouble code P0119 indicates an intermittent problem in the Engine Coolant Temperature (ECT) sensor circuit. This means the sensor is sending erratic signals to the engine control module (ECM), causing unstable temperature readings and improper fuel delivery.
What Does Code P0119 Mean?
The ECT sensor monitors the engine’s coolant temperature and sends data to the ECM for proper fuel mixture and ignition timing. When the voltage or signal from the sensor fluctuates unexpectedly, the ECM stores code P0119.
| Code | Description |
|---|---|
| P0119 | Engine Coolant Temperature Sensor Intermittent |
Common Symptoms of P0119
- Fluctuating temperature gauge readings
- Rough idling or poor fuel economy
- Check Engine Light (CEL) illuminated
- Hard starting when the engine is warm
- Engine cooling fans running constantly
Possible Causes
- Faulty Engine Coolant Temperature (ECT) sensor
- Loose or corroded sensor connector
- Damaged wiring harness
- Low coolant level or air pockets in the cooling system
- ECM software glitch or failure
How to Diagnose and Fix P0119
- Check Coolant Level: Ensure the cooling system is filled and free of air pockets.
- Inspect the ECT Sensor: Look for corrosion, cracks, or loose connectors.
- Use an OBD-II Scanner: Connect the iCarsoft CR Max BT to read live temperature data.
- Compare Live Data: Verify if the ECT readings are consistent with engine temperature.
- Replace the ECT Sensor: If voltage fluctuates or readings are abnormal, replace the sensor and clear the code.
Tip: Use iCarsoft CR Max BT to view real-time coolant temperature data, compare with intake air temperature, and verify accurate readings before replacing parts.
Recommended Diagnostic Tools
- iCarsoft CR Max BT – Advanced bidirectional diagnostic tool for full-system analysis.
- iCarsoft CR Ultra P – Professional-grade scanner for deeper sensor and live data diagnostics.
Summary
OBD-II code P0119 typically indicates an intermittent fault in the engine coolant temperature sensor circuit. Accurate diagnosis with a reliable OBD-II scanner like iCarsoft CR Max BT helps ensure precise readings and prevents unnecessary part replacements.
