Contents: Coolant Temperature Gauge Sensor ↳ Coolant temperature sensor ↳ Minimum coolant level sensor ↳
Note: See warning in paragraph 1 this chapter.
Coolant Temperature Gauge Sensor
1. On 4-cylinder engines, the sensor is installed on the thread at the left end of the cylinder head (see Fig. 6.1).
2. On V-shaped 6-cylinder engines, the sensor is installed on the engine on the left in the front part of the bypass circuit housing (see Fig. 6.2).
Examination
3. If the temperature gauge does not work, first check the fuses (Chapter 12).
4. If the gauge is constantly in the "Hot" range, refer to "Troubleshooting" at the end of this manual when troubleshooting a possible cooling system problem.
5. If the pointer points to "Hot" almost immediately after starting a cold engine, disconnect the coolant temperature gauge sensor wiring connector. If the reading then drops sharply, replace the sensor. If the reading remains high, the gauge wire may be shorted to ground or the gauge itself may be faulty.
6. If the indicator shows a malfunction after the engine has warmed up (after about 10 minutes), and the fuse is good, turn off the engine. Disconnect the sensor wiring connector and connect the white/red wire to ground (on the engine, on bare metal) with an auxiliary wire. If the indicator then points to the "Hot" sector, replace the sensor.
7. If the indicator still does not work, then it is possible that its circuit is broken or the indicator itself is faulty. Details are in Chapter 12.
Removal
8. Drain the cooling system (chapter 1).
9. On 4-cylinder models, remove the resonator support bracket bolts from the front engine compartment crossmember. Loosen the screws holding the two clamps securing the resonator to the air flow meter and prechamber hoses. Then move the resonator away from the thermostat housing (Chapter 4A).
10. On V6 models, remove the water pump drive belt cover. Remove the air intake duct from the air cleaner (Chapter 4A). The battery can be removed for better access (Chapter 5A).
11. On 4-cylinder models, disconnect the expansion tank hose and upper radiator hose from the thermostat housing outlet. Then disconnect the metal coolant pipe/hose from the thermostat.
12. Disconnect the sensor wiring electrical connector (see Fig. 6.12).
13. Unscrew the sensor and remove it.
Installation
14. Clean the hole in the thermostat housing as thoroughly as possible. Then apply a small amount of sealant to the sensor thread. Screw in the sensor and tighten it to the specified torque, then connect the electrical connector to its wiring.
15. Connect the hoses and install the removed components. Add fluid to the cooling system (chapter 1). Start the engine. Check for leaks and that the gauge works.
Coolant temperature sensor
16. The difference between the coolant temperature sensor and the gauge sensor is that it provides data to the engine management system. The same data is used to determine when the radiator fan turns on.
17. On 4-cylinder engines, the sensor is installed on the thread on the top of the thermostat housing (see Fig. 6.17).
18. On V-shaped 6-cylinder engines, the sensor is installed on the engine on the left in the rear part of the bypass circuit housing (see Fig. 6.18).
Examination
19. Disconnect the negative battery cable (Chapter 5, paragraph 1).
20. On 4-cylinder engines, remove the resonator support bracket bolts from the front crossmember of the engine compartment. Loosen the screws of the two clamps securing the resonator to the air flow meter and prechamber hoses. Then move the resonator away from the thermostat housing (Chapter 4).
21. On V-shaped 6-cylinder engines, access to the sensor is difficult. To improve access, remove the intake air duct from the air cleaner and the air cleaner itself (Chapter 4A). Move the sensor wiring to the side.
22. Disconnect the sensor electrical connector.
23. Use an ohmmeter to measure the resistance between the sensor terminals. Depending on the temperature of the sensor probe, the measured resistance may have different values, but within the limits specified in the Technical Requirements. If you change the temperature of the sensor by removing it (see below) and placing it in the refrigerator for a while or by heating it slightly, the resistance should change accordingly.
24. If the readings do not change, then the sensor is faulty and needs to be replaced.
25. Finally, connect the electrical connector and install the removed components.
Removal
26. Disconnect the negative battery cable (Chapter 5, paragraph 1).
27. On 4-cylinder engines, it is not necessary to drain the coolant from the cooling system, which must first cool down. When the engine has completely cooled down, remove the expansion tank filler cap to relieve pressure in the system, and then install the cap. If you work carefully and plug the hole immediately after unscrewing the sensor, the loss of coolant will be minimal. This eliminates the procedure for draining the coolant from the system, which would otherwise need to be done (chapter 1).
28. On V-shaped 6-cylinder engines, drain the liquid from the cooling system (chapter 1).
29. Provide access to the sensor as described in the subparagraph "Checking" (see above).
30. Unscrew the sensor and remove it. If you did not drain the liquid from the cooling system, you must immediately plug the resulting hole.
Installation
31. Clean the sensor hole as thoroughly as possible from the sealant. Then apply a small amount of sealant to the sensor thread. Screw in the sensor and tighten it to the specified torque, and then connect the electrical connector of its wiring.
32. Connect the hoses and install the removed components. Add fluid to the cooling system (chapter 1). Start the engine. Check for leaks.
Minimum coolant level sensor
Examination
33. This sensor (with a plate contact) is installed at the bottom of the expansion tank of the cooling system and is triggered by a float containing a magnet. If the coolant level drops to the MIN mark or below, the corresponding indicator lights up on the front panel.
34. If the indicator lamp does not light during the five-second bulb test, check the bulb and replace it if necessary as described in Chapter 12.
35. To check the sensor itself, disconnect its electrical connector and measure the resistance on its terminals with an ohmmeter. When the float is raised, the resistance should be 90 Ohm, when it is lowered - 150 kOhm.
36. If the readings differ significantly from those indicated above, the sensor is faulty and must be replaced.
37. If the sensor and the light bulb are in good working order, the malfunction may be caused by the wiring or the additional indicator unit (Chapter 12).
Removal
38. Disconnect the negative battery cable (Chapter 5, paragraph 1).
39. Remove the expansion tank (paragraph 7).
40. Disconnect the sensor electrical connector (see Fig. 6.40).
41. Turn the sensor counterclockwise and then pull it out (see Fig. 6.41,a,b).
Installation
42. Installation - in the reverse order of removal. Fill the cooling system (chapter 1). Start the engine and after it has warmed up completely, check for coolant leaks.
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