BMW FRM module issues

Have you ever faced a situation where your BMW headlights don’t turn on or your turn signal doesn’t turn off? If yes, you most likely have a faulty FRM.

In this article, we will learn about the BMW FRM module issues. We will talk about BMW’s FRM, its application, the functions it performs, and the problems it creates when gone faulty.

This article is focused on people:

• Having light or window related issues
• People facing FRM related problems
• Or ones wanting to learn more about BMW FRM

So, what is a BMW FRM?

What is the BMW FRM module?

The BMW FRM is an electrical control unit designed to control light and window-related functions. The module receives signals from several sensors across the car and controls many-body aspects of the vehicle based on it. The FRM also interfaces with the dashboard.

Or simply, FRM is the reason why your DRL’s work in the daytime or your parking light turns on every time you switch to park. It is the FRM that also controls your power windows, exterior mirrors, adaptive headlights, and several other functions.

That’s why if gone bad, it can create several problems at once. However, being common, they are easily recognized. We will discuss these later in the article.

The FRM is also known as the Footwell module because of its location at the driver-side footwell.

Functions controlled by the FRM modules

The Footwell module receives signals from several sensors installed on the car. Based on which it controls your light and windows, and performs other system functions. Most of these sensors are common in all BMWs with some variations.

The common sensors are :

• Height sensors
• Light switch
• Reversing light switch
• Brake light switch
• Hazard warning flasher switch
• Driver’s door switch block
• Door contacts in front doors
• Driver side door lock

By using the feedback from these sensors, the FRM controls the following mechanisms:

Exterior lights

• Headlights
• Taillights
• Sidelight
• Fog light
• Parking light
• Number Plate light
• Turn Signals
• Hazard Warning lights
• Centre high-mount stop lamp
• Adaptive headlights by controlling 2-stepper motor controllers

Interior lights

• Interior Dashboard lights
• Front Courtesy light
• Rear Courtesy light
• Luggage Compartment light
• Glove compartment light
• Footwell light

Footwell Module System Functions

Other than the standard lighting function, the FRM also performs few system functions. Such functions are:

Establishing gateway between LIN Bus and K+ Dash-Can

The Footwell module in BMW establishes a communication between the LIN bus and the K+Dash CAN. Using this connection, the FRM transfers relevant messages to different recipient buses.

Equipment on the LIN Bus:

• Special equipment exterior mirrors
• Driver’s door switch block
• Belt Feeder Controllers x2
• Stepper motor controllers for stepper motors in Adaptive headlights

Waking by means of Various Signals

By using various signals, the Footwell module can be wakened. Such signals are:

• Active K-CAN
• Hazard warning switch turned ON
• Vehicle alarm system triggered
• Terminal-15 ON
• Changed door contacts status

Storing vehicle order

The BMW FRM is also capable of storing vehicle order. The vehicle order is what enables the vehicle to be identified. And it also stores all of the important equipment features of the vehicle.

To store the vehicle order in the FRM, the vehicle must be going at 5 km/h or less with terminal-15 ON.

Other System Functions:

• Exterior mirrors
• Power Window drive
• Central locking system
• 2 belt feeder controller only on E92

FRM Control Units

To control different lighting functions, the FRM uses different control units. Below is the list of all such control units.

Exterior Light Control Units

• DSC: Dynamic Stability Control
• DSC: FLA High-beam Assistant
• LDM: Longitudinal dynamics Management
• RLS: Rain/Light Sensor
• RLSS: Rain/Light solar sensor

Interior Light Control Units

• ACSM or MRS: Advance Crash Safety Module/ Multiple Restraint System
• FZD: Roof Function Centre
• JBE: Junction Box Electronics
• SZL: Steering Column Switch Cluster

Other Control Unit

• Seat Belt Extender Controller (only on E92)

Now that we have discussed the Footwell module and its functions. Let’s talk about the issues it has and the problems you face.

BMW FRM issues

To begin with, the FRM modules are sensitive devices. They are secured tightly at the driver-side footwell. It is out of contact, and to reach it you will need to open a few screws. You can read more about removing BMW FRM here.

But, despite being secured, a little water infiltration or voltage fluctuation can harm these devices. Oftentimes, jump-starting your car or replacing the battery can harm your Footwell module.

This can cause several problems simultaneously. Below is a list of such problems that are caused by a malfunctioning FRM module.

• Malfunctioning Headlights
• Indicators not working
• No interior lights
• No high beam
• Power windows not working
• Dashboard service light always on
• Failed Climate Control
• Tail Lights not turning on/off
• No automatic folding mirrors

In case of a faulty FRM, it is always better to send a faulty footwell module to repair. You can also buy a new one, but it will add a bunch of expenses.

A new FRM module costs anywhere between $400-$500. Then you will need to get it programmed based on your vehicle’s specification, which adds extra. The warranty on these devices is also short given how sensitive these are.

Simply put, a new Footwell module will cost at least 4X the cost of repair. To learn more, you can read one of our articles discussing this topic here.

FRM Module Fault Codes

A faulty FRM is unable to communicate with OBD-2 scanners. So running a diagnostic is unlikely. However, you can find the error codes in other control modules to ensure that your Footwell is faulty.

When diagnosing these, you can get any of the following common error codes.

• 497F – Message Error (status, reverse gear, 0x3B0) Diesel Electronics Receiver Footwell Module Transmitter
• A3B4 – Message (lighting condition) Incorrectly, Transmitter FRM Permanent
• A3C1 – Message (FRM foot space module) Incorrectly receiver COMBI, Transmitter FRM – Permanent
• E72B – Window Error
• E72C – Window Error

Wrapping up

Summing it up, in this post we learned about the FRM module, the different functions it performs, and problems related to it. We hope that this post was all you needed to gain relevant information. And now you have a better understanding of BMW FRM and issues related to it.