The footwell module is also short call “FRM”.The footwell module picks up the signals from the doors and controls the lighting. The footwell module also controls the adaptive headlights. The footwell module is also the interface to the dashboard.Here i take Cooper S R56 as a example to introduce FRM Module.Hope this article will make you to understand footwell module deeply.
Footwell Module Location:
The footwell module is located in the footwell on the driver’s side. The footwell module and the junction box electronics control the power window drives (show as below picture).Sometime you need to locate FRM module remove FRM Footwell Module for Repairing FRM Footwell Module.
Footwell Module and Related Block Diagram for R56
|1||Footwell Module||2||Junction Box Electronics|
|3||Steering column switch center||4||Dynamic Stability Control|
|5||Engine control module||6||Instrument cluster|
|7||Additional instrument||8||Car Access System|
|9||Header/air conditioning system||10||Mirror calibration switch|
Footwell Module System Function:
The footwell module processes the signals from the doors and controls the lighting. The footwell module is also the interface to the instrument cluster.Depending on the equipment version, the footwell module picks up the following signals:
*Reversing light switch
*Brake light switch
*Hazard warning switch
*Switch block, driver’s door
*Driver’s door lock
The following functions are controlled by the footwell module:
*Communication between the LIN bus and body CAN
*Storing vehicle order
*Exterior rearview mirror
*Front power windows
Footwell Module Communication:
The footwell module enables communication to take place between the LIN bus and the body CAN
Footwell Module Store Vehicle Order:
The vehicle order is saved in the footwell module. The vehicle order enables the vehicle to be identified.Besides the type code number,the vehicleorder contains all important equipment features on the vehicle.
Exterior rearview mirror
There are two equipment variations of the switch block in the driver’s door:
Basic version of the driver’s door switch block
The switch block sends its signals directly to the footwell module.
High version of the driver’s door switch block
This switch block is connected to the LIN bus. The requests to adjust the exterior mirrors are sent via the LIN bus.
The lighting functions are integrated into the footwell module. These lighting function are:
Rear fog light
Hazard warning lights
Besides the lighting functions, other exterior lighting functions are also integrated in the footwell module:
Headlight beam height control
Emergency operating mode if the footwell module should fail
Visual alarm after anti-theft alarm has been triggered
Actuation of bi-xenon headlamps
All lighting functions except the additional brake light are activated with pulse width modulated signals by the footwell module. These pulse-widthmodulated signals enable a uniform brightness of the exterior lighting.
On vehicles without a roof control panel, the footwell module actuates the interior lighting in the roof area directly. All footwell module outputs for
interior lighting are pulse-width modulated. With standard equipment, the interior lighting comprises the following components:
Front interior light
Luggage compartment lights
Glove compartment lighting
The following components can also be installed as optional extra for the interior lights:
Rear interior light
The footwell module evaluates the status of the Hall sensors in the door contacts. When the vehicle is locked or unlocked with the mechanical key
element, the footwell module will recognize this request. The footwell module sends a message on the body CAN to the Comfort Access.
The footwell module and the junction box electronics activate the power-window motors. The relays for the front power window motors are located in
the footwell module.