The Auto defogger sensor is installed on front window glass. For safety driving, The Auto defogger sensor judges and sends signal of the occurance of moisture in advance of blowing out the wind for defogging with improvement of visiablilty and comfort.
While controlling the temperature and Mode(direction of wind) set by driver, if the humidity is higher than certain level, Air condtioner control Module automatically controls auto defogging mode. Air conditioner control module changes to go back to the previous driver set mode, if the humidity is decreased.
The Air conditioner control Module automatically controls Intake actuator, A/C, Defogger actuator, Blower motor rpm, Mode actuator in accordance with the amount of humidity on the front glass.
DTC B1284 sets if Auto defogger Mode Actuator sensor signal is at or over 4.9V for 0.3 seconds.
Item | Detecting Condition | Possible Cause |
DTC Strategy |
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Voltage check | 1. Short to battery in signal(Feedback signal) circuit. 2. Open in ground circuit. 3. Faulty auto defoger mode actuator. 4. Faulty Air conditioner control Module. |
Enable Conditions |
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Ignition ON | |
Threshold value |
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Auto defogger Mode Actuator sensor signal is at or over 4.9V for 0.3 seconds. | |
Failsafe |
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If selected Mode was VENT, it is moved and fixed at Close position.
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If the others mode, it is moved and fixed at Open position. |
※ Voltage output according to Actuator position
Door position | Voltage |
CLOSE(VENT, B/L) | About 4.7V |
FLOOR | About 3.94V |
MIX | About 3.29V |
OPEN(DEF) | About 1V |
