P0119 code meaning
Engine Coolant Temperature Sensor 1 Circuit Intermittent/Erratic
Powertrain system Generic code P01xx codes Check engine light
What P0119 means
The engine coolant temperature sensor 1 is an NTC thermistor: the control module feeds 5 V through a resistor, and as the coolant warms the resistance and signal voltage fall. Its value drives cold-start enrichment, idle speed, ignition timing, the radiator fan and the release of closed-loop mixture control. Some Ford engines measure cylinder head temperature instead and calculate a coolant value from it. Coolant temperature can only change slowly because of the thermal mass involved. P0119 is set when the reading jumps faster than physically possible. GM calculates, every second, a window for the next valid value from the previous reading and a sensor time constant of 13 s; readings outside it in three of four samples count as a fault, monitored continuously over two trips. GM/Saab set it after more than 4 s of abrupt changes and then run the radiator fan. Typical causes are loose contacts or a harness chafing as the engine moves.
P0119 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P0119
- Check engine light on
- Temperature gauge jumps
- Radiator fan switches on for no reason
- Occasional rough running or idle fluctuation
Common causes of P0119
- Most likelyLoose contact or corroded connector pins
- PossibleHarness chafing that briefly grounds or opens with engine movement
- PossibleSensor with internal crack or contact fault
- Less likelyAir pockets at the sensor (poorly bled cooling system)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Engine coolant temperature sensorEngine coolant temperature sensor wiring
What each part of P0119 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 1 | Area: fuel and air metering. |
| 19 | The exact fault in that area. |
What to do next
- Note P0119 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0119
What does P0119 mean?
P0119 means "Engine Coolant Temperature Sensor 1 Circuit Intermittent/Erratic". The engine coolant temperature sensor 1 is an NTC thermistor: the control module feeds 5 V through a resistor, and as the coolant warms the resistance and signal voltage fall. It is a generic code, so it means the same on every make.
Is it safe to drive with P0119?
Drive gently and only to a workshop. With P0119 the car can go into limp mode (reduced power) to protect itself.
Will P0119 fail an emissions test?
Yes, it can. P0119 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0119 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0119 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.