Warning. Read the Precautions for Repairing the Engine Control System Before Performing Repairs (see "Precautions when repairing the engine management system").
To perform repair work on a VAZ 2110 car to remove, check and replace the coolant temperature sensor (DTOZH) you will need:
- multimeter (in the voltmeter mode, an ohmmeter with a measurement limit from 100 Ohm to 10 kOhm);
- thermometer (with a change limit of at least 100°С);
- a small heat-resistant container with a volume of about 0.5 liters for water;
- about 0.3 liters of water heated to boiling point.
Recommendation. The thermometer can be replaced with a digital multimeter with thermometer mode.
Removal and inspection
1. Drain the coolant from the engine cooling system (see items 1-7 "Coolant replacement").
2. Remove the air filter (see "Air filter - removal and installation").
3. We release the lock of the wiring harness connector, disconnect the connector from the DTOZH sensor.
4. Connect «negative» voltmeter probe to «mass» engine.
5. Turning on the ignition, use a voltmeter to measure the voltage at terminal A of the wiring harness connector (the designation of the conclusions is applied on the block of the wiring harness).
Note. The voltage at the output must be at least 12 V. If the voltage is not supplied to the connector or it is less than 12 V, then the battery is discharged, the power circuit is faulty or the computer is faulty.
Warning. At the end of the voltage measurement, turn off the ignition on the car.
6. With a 19 mm key, unscrew the sensor and remove it from the thermostat housing. The connection between the coolant temperature sensor and the thermostat is sealed with a copper washer.
7. We connect an ohmmeter to the terminals of the DTOZH sensor.
8. We fill the container with boiling water, immerse the working part of the sensor in water and record the readings of the device at a temperature of about 100°C. As the water cools, we measure the resistance of the DTOZH sensor at temperatures of 90, 80, 70, 60, 50, 45, 40, 35, 30, 25 and 20°C.
If conditions permit, readings can be taken at a lower temperature. The resistance of a serviceable DTOZH sensor should be close to the data indicated in the table:
Coolant temperature,°С | DTOZH sensor resistance, Ohm |
100 90 80 70 60 50 45 40 35 30 25 20 15 10 5 0 |
177 241 332 467 667 973 1188 1459 1802 2238 2796 3520 4450 5670 7280 9420 |
Faulty coolant temperature sensor (DTOZH) replace.
Installation
1. We install on the car all the removed parts in the reverse order of removal.
2. Fill the engine cooling system with liquid.
3. We start the engine and make sure that there is no coolant leak from under the sensor. If necessary, we wrap the DTOZH sensor more tightly into the thermostat housing.
Recommendation. If it was not possible to eliminate the leak in this way, the coolant temperature sensor should be reinstalled by applying a heat-resistant sealant to its threaded part or replacing the copper washer.