The incar temperature sensor located at heater control unit contains a thermistor which measures the temperature of the inside. The signal,decided by the resistance value which changes in accordance with perceived inside temperature, is delivered to heater control unit and according to this signal, the control unit regulates incar temperature to intended value
The ECM sets DTC B1234 if there is an open circuit in incar temp sensor signal harness or the measured resistance value of sensor is more than threshold value(about 144.79㏀)
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Voltage check | ● Open Circuit in harness ● Fault incar temp.sensor ● Fault A/C Control Unit |
Threshold value | ● > 4.9V | |
Detecting time | ● 0.3sec | |
FAIL SAFE | ● Control with the vlaue of 23℃(73℉) |
Temperature(℃) | Resistance(㏀) | Temperature(℃) | Resistance(㏀) |
-30 | 144.79 | 25 | 10 |
-15 | 63.59 | 35 | 6.73 |
0 | 30.03 | 60 | 2.72 |
15 | 15.21 | 80 | 1.43 |
