The In Car Tenperature Sensor contains a thermistor which measures the temperature of the inside the vehicle. The signal, based on the resistance value, is delivered to the HVAC control unit. This information is used to control the vent output temperature.
DTC B1233 sets if the In-Car Temperature Sensor signal is at or below 0.1V for 0.3 seconds.
Item
Detecting Condition
DTC Strategy
Voltage check
Short circuit in harness
Faulty incar temp.sensor
Faulty A/C Control Unit
Enable Conditions
Ignition ON
Threshold value
Sensor signal is at or below 0.1V for 0.3 seconds
Failsafe
Substituded In-Car Temp. = 25? (77?)
? Resistance value of incar temp sensor as a function of temperature.
Temperature(?/?)
Resistance(?)
-20/-4
285.6
20/68
37.4
-10/14
169
30/86
24.1
0/32
97.7
40/104
15.9
10/50
59.67
50/122
10.8