General Information

Front Area Module

B1907 Rain Sensor Fault 3 - General Information

Component Location





General Description

FAM controls the low/high wiper relay according to rain sensor signal when the wiper auto switch is turned to ON under IG ON.
As the wiper INT switch is set at AUTO mode, combination switch transmits value of INT step to ECW by LIN communication. And, ECW communicates with FAM by CAN.
[FAM output signal (FAM -> Rain sensor)]
FAM transmits sensitivity step signal from INT switch to the rain sensor by pulse signal.




[FAM input signal (Rain sensor -> FAM)]
The Rain sensor transmits moisture status and the desired wiper speed to FAM by pulse signal.




* The Rain sensor has various outputs according to each modes as below. (Duty cycle changes)
Rain sensor output signal (Rain sensor -> FAM)






DTC Description

FAM outputs this code when FAM can't receive data from the rain sensor.
1. In case of shaking the rain sensor after detaching from windshield.
2. In case each circuits of input and output are shorted to ground.
3. In case each circuits of input and output are shorted to power.
4. In case each circuits of input and output are open.
5. In case the rain sensor connector is disconnected.

DTC Detecting Condition





Diagnostic Circuit Diagram





Signal Waveform & Data




















Fig.1) Signal waveform at Wiper (INT) Switch "Auto Fast"-Rain Sensor output Signal.
Fig.2) Signal waveform at Wiper (INT) Switch "Auto Fast"-Rain Sensor Input Signal.
Fig.3) Signal waveform at Wiper (INT) Switch "Auto low"-Rain Sensor output Signal.
Fig.4) Signal waveform at Wiper (INT) Switch "Auto low"-Rain Sensor Input Signal.
Fig.5) "Wiper state" & "Rain sensor" with Wiper (INT) Switch "AUTO" and idle.