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P0119Engine Coolant Temperature Sensor 1 Circuit Intermittent/Erratic

What it means

The engine coolant temperature sensor signal jumps or drops out for short moments. The ECU uses coolant temperature for cold-start fuelling, idle speed, the radiator fan and the temperature gauge.

Symptoms

  • Hard starting, rich running or black smoke
  • Radiator fan running all the time
  • High idle or wrong temperature gauge

Common causes

  • Loose terminal or corroded connector
  • Chafed harness
  • Failing sensor

What to check first

  1. Graph the reading while wiggling the harness
  2. Check terminal tension
  3. Inspect the harness near hot or moving parts
Can I drive with P0119? Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

How to test the parts behind P0119

Coolant temperature sensor (ECT)Wiring, typical values, multimeter and scope tests

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P0119: questions and answers

What does P0119 mean?

P0119: Engine Coolant Temperature Sensor 1 Circuit Intermittent/Erratic. The engine coolant temperature sensor signal jumps or drops out for short moments. The ECU uses coolant temperature for cold-start fuelling, idle speed, the radiator fan and the temperature gauge.

What are the symptoms of P0119?

Hard starting, rich running or black smoke. Radiator fan running all the time. High idle or wrong temperature gauge.

What causes P0119?

Loose terminal or corroded connector. Chafed harness. Failing sensor.

How do you diagnose P0119?

1. Graph the reading while wiggling the harness 2. Check terminal tension 3. Inspect the harness near hot or moving parts

Can I drive with P0119?

Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.