DESCRIPTION
An automatic dimming inside rear view mirror is an available factory-installed option on this vehicle. This mirror features a thin layer of ElectroChromic (EC) material sandwiched between two pieces of conductive glass to make up the face of the mirror. The EC material explains how this mirror also became known as the ElectroChromic Mirror Module (ECMM). The ECMM will automatically change the reflectance of the inside rear view mirror glass to reduce the glare of headlamps approaching the vehicle from the rear while driving during dark or night time conditions.
The ECMM is a completely self-contained unit that replaces the standard equipment prismatic inside rear view mirror. Besides the mirror glass, the ECMM includes a power switch, a Light Emitting Diode (LED) power indicator, two photocell sensors, the electronic mirror control circuitry and the hardware necessary to communicate as a Local Interface Network (LIN) slave node on the LIN data bus.
The ECMM may also integrate these other optional features
- Imager Camera - For vehicles equipped with the SmartBeam® Automatic Headlamp High Beam System, a digital imaging camera is integral to the ECMM mounting bracket and shares the LIN data bus communication features of the ECMM.
- Telematics Microphones - For vehicles equipped with the optional Uconnect™ Hands-Free Communication System, two hard wired telematics microphones are integral to the upper surface of the ECMM housing.
Hard wired circuitry connects the ECMM to the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the ECMM through the use of a combination of soldered splices, splice block connectors and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention as well as pin-out and location views for the various wire harness connectors, splices and grounds.
The ECMM cannot be repaired or adjusted. If any component of this unit is ineffective or damaged, the entire ECMM unit must be replaced.
OUTSIDE MIRROR - The automatic dimming driver side outside rear view mirror is able to automatically change its reflectance. The automatic dimming outside rear view mirror replaces the standard equipment outside rear view mirror. The two layers of conductive mirror glass with a thin layer of electrochromic material between them is contained within the outside rear view mirror glass case. However, this mirror relies upon the photocells and mirror control circuitry of the automatic dimming inside rear view mirror to control its reflectance.
The automatic dimming outside rear view mirror is secured to the same mounting flag on the front door panel and in the same manner that is used to mount the standard equipment outside rear view mirrors. The mirror is connected to the vehicle electrical system through a dedicated take out and connector of the front door wire harness. The automatic dimming circuitry of the outside rear view mirror receives current through auto day/night mirror feed (+) and return (-) circuits from the inside rear view mirror, and will only operate when the ignition switch is in the ON or START positions.
The automatic dimming outside rear view mirror sensitivity cannot be repaired or adjusted. If any component of this unit is ineffective or damaged, the entire outside rear view mirror unit must be replaced. For service procedures, refer to MIRROR, OUTSIDE REARVIEW, REMOVAL , MIRROR, OUTSIDE REARVIEW, GLASS, REMOVAL , MIRROR, OUTSIDE REARVIEW, INSTALLATION and MIRROR, OUTSIDE REARVIEW, GLASS, INSTALLATION .
OPERATION
The automatic dimming inside rear view mirror is also known as the ElectroChromic Mirror Module/ECMM. A thin layer of ElectroChromic (EC) material between two pieces of conductive glass make up the face of this mirror. Two photocell sensors allow the ECMM circuitry to monitor light levels and automatically adjust the reflectance of the mirror glass.
An ambient photocell sensor is located on the forward-facing (windshield side) of the ECMM housing, to detect the ambient light levels outside of the vehicle. A headlamp photocell sensor is located inside the ECMM housing behind the mirror glass and faces rearward, to detect the level of the light being received at the rear window side of the mirror glass. When the circuitry of the ECMM detects that the difference between the two light levels is too great (the light level received at the rear of the mirror is much higher than that at the front of the mirror), it automatically begins to darken the mirror.
The ECMM operates on battery current received through a fused ignition output (run) fuse in the Junction Block (JB) (also known as the interior Power Distribution Center/PDC) and has a path to ground at all times through a takeout and eyelet terminal of the body wire harness secured to the body sheet metal. These connections will only allow the ECMM to operate when the status of the ignition switch is On. In addition, a power switch on the EC mirror housing allows the vehicle operator a manual control of whether the ECMM automatic dimming feature is enabled or disabled. A green Light Emitting Diode (LED) unit illuminates through the face of the ECMM housing to provide an indication whenever the automatic dimming feature is enabled.
The Local Interface Network (LIN) slave node circuitry integral to the ECMM allows it to monitor electronic reverse switch status messages received over the LIN data bus. This input allows the ECMM to automatically disable its self-dimming feature whenever the vehicle is being driven in Reverse. On vehicles equipped with the optional Automatic High Beam Module (AHBM) and digital imager camera, the AHBM also communicates with the BCM over the LIN data bus through the LIN slave node circuitry of the ECMM.
The hard wired inputs and outputs for the ECCM may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the EC mirror system or the electronic controls and communication between other modules and devices that provide some features of the EC mirror system. The most reliable, efficient, and accurate means to diagnose the EC mirror system or the electronic controls and communication related to EC mirror system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.
Each power mirror articulation mechanism is driven by two individual Direct Current (DC) reversible electric motors. Each motor also features Positive Temperature Coefficient (PTC) protection. One motor in each mirror controls horizontal (left and right) movement, while the second motor controls vertical (up and down) movement. The power mirror selector switch setting determines which mirror is to receive the output from the power mirror control switch.
The power mirror control switch determines which motor will be energized and the direction in which the motor will be driven. When battery current and ground are output from the control switch to the two motor terminals, the motor rotates in one direction. When the switch output polarity to the motor connections is reversed, the motor rotates in the opposite direction. The mirror articulation mechanism also incorporates clutches that protect the mechanism by disengaging the drive whenever the travel limits of the articulation swivel have been reached.
The power mirrors as well as the hard wired input circuits for the mirrors may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information.
The power mirror switch circuitry within the driver side front door power switch module is connected to battery current through a non-switched fused B(+) circuit received from a fused B(+) fuse in the underhood Power Distribution Center (PDC). The power mirror switch circuitry also has a path to ground at all times through a take out and eyelet terminal of the body wire harness that is secured to the body sheet metal. These connections allow the power mirror switch to remain operational regardless of the status of the ignition switch.
A latching push button power mirror selector switch has three positions, L (left), R (right) and N (neutral). After the right or left mirror is selected, one of the four directional arrows on the momentary power mirror control switch disc is depressed to move the selected mirror up, down, right or left. The power mirror control switch directs the appropriate battery current and ground feeds to the proper horizontal or vertical motor within the mirror articulating mechanism of the selected power mirror.
The power mirror switches as well as the hard wired input and output circuits of the switches may be diagnosed using conventional diagnostic tools and procedures. Refer to SWITCH, LOCK, DIAGNOSIS AND TESTING .
See also:
• DESCRIPTION