Automatic Dimming Inside Rear View Mirror System

WARNING: This page is about a different car, the 2017 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

The automatic dimming inside rear view mirror is available factory-installed equipment on this vehicle. This mirror is also known as the ElectroChromic Mirror Module (ECMM). This mirror system uses an ElectroChromic (EC) material and will automatically adjust the reflectance of the mirror glass to reduce glare from the headlamps of following vehicles during dark or night time driving conditions. Reducing glare will improve driver comfort and vision under these driving conditions. The components of the automatic dimming inside rear view mirror system are completely self-contained within the inside rear view mirror. Refer to MIRROR, AUTOMATIC DAY AND NIGHT, DESCRIPTION .

Certain functions and features of the EC mirror system may rely upon resources shared by other electronic modules in the vehicle over a Local Interface Network (LIN) data bus as well as over the Controller Area Network (CAN) data bus. Other electronic modules in the vehicle that may affect EC mirror operation are:

Body Control Module - The Body Control Module (BCM) is located beneath the instrument panel on the driver side of the vehicle. The BCM controls many of the body electrical system components. The BCM is both a LIN master node and a gateway to the CAN data bus. Refer to MODULE, BODY CONTROL (BCM), DESCRIPTION .
Powertrain Control Module - The Powertrain Control Module (PCM) is located beneath the hood in the engine compartment of the vehicle. The PCM controls many of the powertrain electrical system components. The PCM communicates on the CAN data bus. Refer to MODULE, POWERTRAIN CONTROL (PCM), DESCRIPTION .
Transmission Control Module - On vehicles with an automatic transmission, the Transmission Control Module (TCM) controls many of the automatic transmission electrical system components. The TCM communicates on the CAN data bus. Refer to MODULE, TRANSMISSION CONTROL (TCM), OPERATION .

These components and their controls are combined to provide the following EC mirror system feature:

Dimming Disabled In Reverse - The automatic dimming feature of the EC mirrors is disabled anytime the Reverse position of the transmission is selected.