Mazda CX-9 2007 Service Highlights page 478

Lights off operation
1. When the light switch is in the AUTO position the illumination level sensors in the auto light sensor (installed in
the windshield) detect the illumination level above and in front of the vehicle.
2. If the upward and forward illumination level sensor detect approx. 4000 lux or more for 1.0 s in front of and
above the vehicle, the headlight and TNS off control signal is sent to the auto light/wiper control module.
3. The microcomputer in the auto light/wiper control module receives the control signal and turns off the current to
transistor A, causing the TNS relay to also turn off.
4. When the TNS relay turns off, the TNS also turns off.
5. The microcomputer in the auto light/wiper control module receives the control signal and turns off the current to
transistor B, causing the headlight relay (LO) to also turn off.
6. When the headlight relay (LO) turns off, the headlights (low-beam) also turn off.
B+
TNS
RELAY
TAIL
TNS
2G
TRANSISTOR A
2M 2N
TNS HEAD AUTO
OFF
Fail-Safe Function
• When a auto light sensor malfunction or a communication error between the auto light sensor and auto light/
wiper control module is detected, the auto light/wiper control module initiates controls as indicated in the fail
safe function table.
Fail-Safe Function Table
Malfunctions
• auto light sensor error
• auto light sensor
communication error
09-18–12
LIGHTING SYSTEMS
B+
H/L LOW H/L HI
RELAY RELAY
HIGH-BEAM
ILLUMI
INDICATOR
LIGHT
HEAD LIGHT
(LOW-BEAM)
2K
TRANSISTOR B
2L
2O
AUTO
LIGHT
PASS
HI SENSOR
LO
LIGHT SWITCH
Fail-safe function
Before operation
Headlight illuminated
TNS illuminated
Off
B+
BCM
HEAD LIGHT
(HIGH-BEAM)
2E 2H 2A 2C
IG1
INSTRUMENT
CLUSTER
After operation
• Ignition switch lock position
Maintains headlights
• When a auto light sensor malfunction
on
is cleared
Maintains TNS on
• When communication is restored
• When the light switch is in a position
Maintains turn-off
other than AUTO
B+
ROOM
2D
AUTO LIGHT/WIPER
CONTROL MODULE
2F
METER
DLC-2
ac9uun00000585
Recovery items