Checking the temperature sensor
1. Disconnect the multi-pin connector from the coolant temperature gauge sensor 3 (see illustration).
5.1 Disconnect the multi-pin connector from coolant temperature gauge sensor 3. The illustration shows a 1.4-/1.6-liter petrol engine (K7J/K7M),
Caution: The plug should be disconnected by holding it by the body, not by pulling on the wire.
2. Connect the voltmeter to the sensor plug and to the ground (-).
3. Turn on the ignition and check if there is power. If there is no voltage, check the condition of the wires.
4. Connect an ohmmeter to both sensor contacts and check its resistance. The obtained value should correspond to the resistance with a cold engine (see table). If the ohmmeter shows 0 Ohm or ∞ Ohm, the sensor should be replaced. If the sensor resistance does not correspond to the nominal values, it should be unscrewed for testing.
Caution! To prevent coolant from leaking out through the sensor hole, drain and collect some of it in a container.
5. Place sensor 2 in a container with water (see illustration), holding it on a wire so that it does not touch the walls of the container with water.
5.5 Lower sensor 2 into a container with water, holding it on the wire so that it does not touch the walls of the container with water
6. Connect an ohmmeter to the sensor (see illustration 5.5).
7. Heat the water in the container and compare the sensor resistance data with the nominal values (see table).
| Temperature | Sensor resistance |
| + 4°C | 7.5±0.5 kOhm |
| + 20°C | 3.5±0.5 kOhm |
| + 80°C | 335±35 Ohm |
| + 90°C | 240±30 Ohm |
If the data obtained during the sensor check does not correspond to the nominal values, the sensor should be replaced.
8. Screw the sensor back into place and connect the power plug. Tighten the sensor with a slight force.
9. Top up the coolant and bleed air from the cooling system.
10. Perform a test drive and check the tightness of the temperature sensor fit.