The In-Car Sensor contains a thermistor which measures the temperature of the vehicle's interior. The signal is used by the HVAC control unit when controling AC functions.
DTC B1234 sets if In-Car temperature sensor signal is at or over 4.9V for 0.3 seconds.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
•
Voltage check | 1. Open in signal circuit 2. Short to battery in signal circuit 3. Faulty In-Car temperature sensor 4. Faulty A/C Control Unit |
Enable Conditions |
•
Ignition ON | |
Threshold value |
•
Sensor signal is at or over 4.9V for 0.3 seconds | |
Failsafe |
•
Substituded In-Car Temp. = 25℃ (77℉) |
※ Resistance value of incar temp sensor as a function of temperature.
Temperature(℃/℉) | Resistance(㏀) | Temperature(℃/℉) | Resistance(㏀) |
-20/-4 | 285.6 | 20/68 | 37.4 |
-10/14 | 164 | 30/86 | 24.1 |
0/32 | 97.7 | 40/104 | 15.9 |
10/50 | 59.67 | 50/122 | 10.8 |
