| Pos. | Spare part number | Name |
| A | - | Mirror with manual dimming |
| B | - | Auto-dimming mirror |
| 1 | - | Mirror Bracket Cover (2 parts) |
| 2 | - | Rear facing light sensor |
| 3 | - | Forward facing light sensor |
| 4 | - | Humidity sensor in the cabin |
| 5 | - | Manually adjustable dimming mirror lever |
The interior rearview mirror is manually or automatically dimmed by an electric drive. Some vehicles have a humidity sensor built into the housing of the electric mirror.
Mirror with manual dimming
The manually adjustable dimming mirror consists of a prismatic glass enclosed in a housing which is attached to the mirror bracket by means of a ball joint.
To darken the mirror manually, use the lever located on the back of the mirror housing. Using the lever, the mirror is moved from the "day" position to the "night" position.
Auto-dimming mirror
The auto-dimming mirror consists of electrochromatic glass enclosed in a housing which is secured to the mirror bracket by a ball joint. The mirror bracket incorporates an 8-pin electrical connector which is connected to the overhead panel wiring harness. This wiring harness provides a hardwired connection and Local Interconnect Network (LIN) communication with the CJB.
Light sensors are mounted in the front and rear of the mirror housing. The sensors control the automatic dimming function, reducing the brightness of glare caused by the headlights of cars following behind.
The automatic dimming function is always active when the ignition is set to power mode 4 (accessory power) and power mode 6 (ignition). The forward-facing light sensor monitors the background light level in front of the vehicle, and the rear-facing light sensor monitors the light level behind the vehicle. When the light level behind the vehicle exceeds the background light level in front of the vehicle, the automatic dimming circuit darkens the surface of the interior rearview mirror.
The automatic dimming is deactivated when reverse gear is selected to provide the driver with the clearest possible view. On vehicles with an automatic transmission, the reverse gear selection signal is sent from the TCM via the high-speed CAN bus to the CJB. The CJB then supplies voltage to the electric mirror. On vehicles with a manual transmission, the reverse gear selection signal is sent from the transmission selector,
Humidity sensor in the cabin
Depending on the vehicle specification, the auto-dimming mirror may also have a built-in interior humidity sensor. The humidity sensor is located at the rear of the mirror housing, near the windshield, and provides information to the ATC module about the likelihood of the windshield fogging. This information is used to adjust the automatic operation of the climate control system. For more information, refer to the chapter: Control Components (412-01 Climate Control, Description and Function).
Comments on this article