P0119

Engine Coolant Temperature Sensor 1 Circuit Intermittent

Car Fault Codes Cooling & lubrication

Can you still drive? With care, short trips only

Who can fix it? DIY with some experience

Typical repair time 30 minutes – 2 hours

Typical cost SAR 80 to 500

What it means

The engine computer has seen the engine coolant temperature (ECT) reading jump suddenly or drop out for short periods, a change real engine temperature cannot make so quickly. The cause is usually a weak connection in the connector or wiring, and it can make the fans switch on suddenly or the temperature gauge flicker.

Symptoms4

Check engine light that comes on and goes off.
Sudden temperature gauge swings on some cars.
Radiator fans switching on and off for no clear reason.
Intermittent stumbling or hesitation.

Possible causes5

Loose or corroded connector pins from heat or coolant leaks.
Internally cracked wire or a wire rubbing on metal.
Weak shared ground point.
Intermittent internal sensor failure.
Air pocket in the cooling system that sometimes exposes the sensor to air.

How to diagnose5

Review the freeze frame data to learn when the fault occurred.
Watch the coolant temperature reading on a scan tool while gently moving the harness and connector, looking for jumps.
Inspect the connector pins for grip and corrosion.
Check the coolant level and make sure there is no air in the system.
Trace the harness for rubbing points near hot parts.

How to fix5

Clean the connector pins or replace the connector.
Repair the chafed harness and secure it away from heat.
Top up the coolant and bleed air from the system.
Replace the coolant temperature sensor if its reading still jumps with good wiring.
Clear the codes and drive until the engine reaches operating temperature to confirm a steady reading.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

The fix is often a low-cost connector or wire repair; it rises a little for a new sensor or a long fault trace.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Does a flickering temperature gauge mean the engine is overheating?

Not necessarily. Sudden jumps are usually electrical, but check the coolant level because air pockets can cause it too.

Can I drive with this code?

Yes, carefully, while watching the temperature gauge and coolant level until it is repaired.

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This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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