1. We prepare the car for the operation (see "Vehicle preparation for maintenance and repair").
2. We release the retainer of the wiring harness block and disconnect it from the coolant temperature sensor.
3. Connect "negative" voltmeter probe to "mass" engine.
4. Turning on the ignition, measure the voltage at the output with a voltmeter "A" wiring harness pads. The voltage at the output must be at least 12 V. If the voltage is not supplied to the block, then this indicates a malfunction in the power supply circuit or the computer.
5. Turn off the ignition.
6. Key by 19 mm unscrew the temperature sensor and remove it together with the sealing washer from the body of the pipe of the engine cooling system.
7. Connect an ohmmeter to the sensor terminals.
8. Fill the container with hot water and immerse the working part of the sensor into it. We record the readings of the device at a temperature of about 90°C. As the water cools, we measure the resistance of the sensor at a temperature of 80, 60, 40, 30 and 20°C.
The resistance of a good sensor should approximately correspond to the data indicated in the table:
Coolant temperature,°C | Coolant temperature sensor resistance, Ohm |
90 | 250 |
80 | 340 |
60 | 670 |
40 | 1500 |
30 | 2250 |
20 | 3500 |
In case of large discrepancies in the data, the sensor is replaced.
Installation
1. The sensor is installed in the reverse order.
2. We start the engine and make sure that there is no coolant leak from under the sensor. Tighten it further if necessary. If it was not possible to eliminate the leak in this way, we reinstall the sensor by applying a heat-resistant sealant to its threaded part.