HEXA

1413 / 1906

ELECTRICAL
111
2. AUTO LIGHT FUNCTION:
 Auto Light function is activated if the auto light
switch is in auto mode and ignition is ON.
 The light sensor send the DATA to LIN based
controller through LIN communication which
indicate the ambient light condition & tunnel
condition
 "RLS sends when to activate the light and with
which speed the wipers needs to be activated
over LIN to BCM'.
 Both auto light and auto rain function has
separate control.
Rain Light sensor Controller interfacing with
BCM to activate the auto light function:
 LIN based controller supplies the PWM signal
to the Body Control Module.
 The signal to be evaluated by the BCM, decides
when to activate the Auto light function, which
includes:
 Parking light ON
 Head lamp ON (Low/high beam)
 Cockpit dimming signals PWM
FAIL SAFE MODES OF RLS & BCM:
AUTO LIGHT:
During below failure conditions the BCM will
operate the low beam & parking lights:
 RLS software fails and there is no LIN
communication between RLS and rain light
controller. (Addition with low beam & parking
lights user can operate manual High beam
through combination switch ).
 Wiring harness failure (open circuit or short to
battery or short to ground) between RLS to RL
controller or RL controller to BCM. (Addition
with low beam & parking lights user can operate
manual High beam through combination
switch).
 BCM software failure. (Only low beam &
parking light is possible).refer BCM H/W
failsafe/lime home mode from BCM section.
 Master light switch (Head lamp) switch gets
failed or disconnected or any wiring harness
issue (open circuit or short to battery or short to
ground) between MLS & BCM. (Only low beam
& parking light is possible).