The action of the coolant temperature thermocouple sensors and failure analysis

Coolant temperature thermocouple sensor, its internal thermistor, as the cooling fluid temperature change, and ECU by THW terminal measured pressure value changes, ECU according to the partial pressure value to judge the coolant temperature. So, when using auto cooling fluid on the thermocouple temperature sensor is used for what? When the car engine run into problems, how should the malfunction analysis from the coolant temperature thermocouple sensors?

the role of the coolant temperature thermocouple sensors:

1, responsible for controlling mixture vapor concentration, the lower the temperature, the mixed gas grows; The higher the temperature, the rarer mixed gas.

2, responsible for warm machine control motor speed, speed under 40 ℃ for 1500 rmin, 40 ~ 70 ℃ speed is 1100 rmin.

3, responsible for controlling the radiator fan, above 85 ℃ began to low-speed rotation, 105 ℃ at high speed.

4, responsible for the control of automatic transmission, 56 ℃ above torque converter into locking condition, 70 ℃ transmission allowed into overdrive.

5, is responsible for the control air conditioning, 120 ℃ air conditioning out of control.

coolant temperature thermocouple sensor fault analysis

the engine coolant temperature thermocouple sensor circuit, data flows show that high temperature above 100 ℃, mixed steam too loose wouldn't start; Thermocouple sensor circuit or a wire poor contact, the data display - flows Below 30 ℃ low temperature, cause vapor mixture too thick, exhaust smoke.

obd - Ⅰ system set engine control units will coolant temperature induction temperature defined in - thermocouple sensors 35 ℃ ~ 120 ℃, exceeds or is lower than this range, the control unit can judge thermocouple sensor fails, there will be no fault code in the scope. If the coolant temperature thermocouple sensor circuit, switch on the ignition switch data flow display coolant temperature over 100 ℃, but since there is no up to 120 ℃, so leave no fault code.

obd - Ⅱ monitoring system of electrical appliances, mainly to provide the relevant information or common information of thermocouple sensor information, in order to determine which thermocouple sensor fault, it is short circuit or open circuit and other information. Information such as the coolant temperature thermocouple sensor and the inlet temperature of the thermocouple sensor information or start time after the comparison, it can be concluded that coolant temperature thermocouple sensor information is accurate, if there is a short circuit or open circuit fault thermocouple sensor. So the coolant temperature thermocouple sensors OBD - after a short circuit Ⅱ system leaves fault codes.

more high quality thermocouple sensor from

key words: thermal resistance, thermocouple, thermal resistance, platinum resistance, PT100, PT1000, pressure thermocouple sensor, digital temperature thermocouple sensor