Purpose
The auto light sensor detects the illumination level above and in front of the vehicle and outputs it to the front body control module (FBCM).
Function
The auto-light sensor uses the upward illumination level sensor to detect the illumination level above the vehicle, and uses the forward illumination level sensor to detect the illumination level in front of the vehicle.
Illumination level adjustment function
The illumination level can be switched through 5 levels by using the Mazda Modular Diagnostic System (M-MDS) or the audio unit (with color LCD)..
On-board diagnostic function
If there is a malfunction in the auto light sensor, notifies the front body control module (FBCM) and detects a DTC from the front body control module (FBCM).
For details on DTCs, refer to the diagnostic system (front body control module (FBCM)), DTC table (front body control module (FBCM)) in the Workshop Manual.
Construction
The auto-light sensor is integrated with the rain sensor as a single unit.
The auto light sensor consists of lens, forward illumination level sensor (photodiode), upward illumination level sensor (photodiode), and microcomputer.

Operation
CAUTION:
Correct illumination level detection is not be possible under the following conditions and could cause the system to operate incorrectly.
Stickers or labels are attached to the auto-light sensor area on the windshield.
Dirt is adhering to the the auto-light sensor area on the windshield.
1. The auto light sensor detects the illumination level above and in front of the vehicle when the ignition is switched ON and the light switch is operated to the AUTO position.
2. The auto light sensor outputs a headlight (LO) on signal to the front body control module (FBCM) according to the detected illumination level.
Fail-safe
Function not equipped.
Adaptive Front Lighting System (Afs) Off Switch Inspection
Back Up Light Switch InspectionTweeter Inspection
1. Disconnect the negative battery cable..
2. Remove the side speaker grille..
3. Remove the tweeter..
4. Verify that the resistance between the tweeter terminals is as indicated in
the table.
If not as indicated in the table, replace the tweeter.
Without Bose®
With B ...
Lights On Reminder Warning Alarm
Purpose
The lights-on reminder warning alarm notifies the driver that the TNS and
headlights are not turned off.
Function
The instrument cluster receives the following vehicle condition signals via
the CAN signal from the start stop unit and rear body control module (RBCM). ...
Intake Manifold Vacuum Inspection
1. Disconnect the evaporative hose No.3 (purge solenoid valve side) and install
the vacuum gauge..
2. Verify that the intake air hoses are installed securely.
3. Warm up the engine.
4. Measure the intake manifold vacuum while idling (no load) using the vacuum
gauge.
If not within t ...