F20 - F30 Rain/Light Sensor Retrofit Guide

What does RLSBS sensor for?

RLSBS is abbreviated of rain, light, solar, and condensation sensor. For F20/F30 series, RLSBS sensor is install on the windshield behind the rearview mirror (There is no need to change the windshield with different sensor type).

Detail description for each sensor:

Rain sensor

The rain sensor is an optical sensor and consists of an optical element. An electronic component is also integrated. Apart from the evaluation electronics, three optical transmitter and receiver diodes are integrated in the electronic component. The transmit diodes and the receiver diodes function in the infrared range.

The rain sensor uses transmit and receiver diodes (infrared) to evaluate the degree of reflection from the windscreen. The grouping of transmit and receiver diodes in pairs creates measurement paths. The rain intensity is detected via the measurement paths.

Rain/light sensor

The rain/light sensor is also an optical sensor and consists of two photo diodes and the corresponding electronic evaluation unit. A photo sensor that works in the infrared range is aligned forwards and it picks up the light that strikes the front (frontal light). A second diode; which works mainly in the visible light spectrum, is aligned upwards and picks up the light striking from above (ambient brightness).

Solar sensor

The solar sensor consists of two photo sensors. The photo sensors work in the infrared range.

The solar sensor is used for the range of functions of the integrated automatic heating and air conditioning system (IHKA). The solar sensor measures the sunlight on the vehicle. When doing this, the sunlight on the driver's side and the passenger's sides are detected separately.

Condensation sensor

The condensation sensor detects window condensation indirectly. In other words, the condensation sensor determines the boundary conditions under which condensation forms on the windows.

The condensation sensor measures the moisture on the windscreen as well as the temperature of the windscreen in the vehicle interior. The evaluation electronics in the condensation sensor evaluates the signals and outputs the data as a message across the data interface (local interconnect network bus). The condensation sensor is responsible for the range of functions of the integrated automatic heating and air conditioning system (IHKA).

Brief component description:

Rain-light-solar-condensation sensor is installed in the mirror base. The sensor is located in the wiper range of the windscreen wiper.

The sensor locks with a retaining spring on a mounting plate. The mounting plate is firmly bonded to the inside of the windscreen.

There is a gel between the sensor and the windscreen. The silicone gel is for optically linking to the windscreen.

The power distribution box at the front supplies power to the sensor. The sensor's signals are transferred through the data buses.

The graphic below shows a third-generation rain-light-solar-condensation sensor as an example.

What does this DIY do?

This DIY will guide you on how to change/code the SBS sensor that can only detect solar and
condensation to the RLSBS sensor with rain, light, solar, and condensation sensor. The bimmer can
be either F20/F30 series with automatic air condition.

Part required:

BMW OEM RLSBS: 61 35 9 293 279 (newer part) or 61 35 9 270 588

Tools required:

1. Small screw driver

2. Computer with esys installed

3. OBD/Ethernet cable

Installation of RLSBS sensor Instructions:

1. Remove rearview mirror/sensor cover

   1. Remove cover by pressing the location per the figure below to release lock

       

   2. Pull the cover away to remove

2. Remove rearview mirror

   1. Remove the wiring connector

   2. Move the mirror base left/right and pull down parallel the windshield

      

3. Remove the old SBS sensor

   1. Remove the connector on top of the SBS sensor (3 wires)

   2. Use small screw driver to pry the spring clip outward on one side until it release (be careful not to scrap the windshield with screw driver)

      

   3. Remove the spring clip

   4. Remove the sensor be careful not to touch the front of the sensor (silicone)

4. Install RLSBS sensor (Do not touch the sensor area!)

   1. Clean sensor are of the windshield

   2. Remove the sensor cover

   3. Install RLSBS sensor

   4. Put cover on old sensor

   5. Plug in the electrical connector to RLSBS sensor (3 wires)

5. Install rearview mirror

   1. Plug in the electrical connector to the windshield

   2. Align rearview mirror to the mounting

   3. Slide rearview mirror mounting bracket until it seats properly

6. Install RLS/rearview mirror plastic cover

7. Follow to the coding section

Head Light Switch Modification:

The head light that does not come with automatic light position needs to be modified to allow the knob to turn pass “0” position. This instruction will detail out the process to modify the switch to allow the head light switch to turn counter clockwise pass “0” position.

Instructions:

1. Remove air outlet above head light switch by pulling prying and pulling it straight out (no
   need to pull the trim out).

    

2. Remove head light switch by pressing the two metal retainers (access thru the air outlet opening) and pull top of head light switch out first then disconnect electrical connector. Remove head light assembly out from the car.

3. Remove the knob from head light assembly by pulling it straight out. If you cannot remove the knob you will have to disassembly housing then use screw driver to push the knob out.

   

4. Once the knob is out remove the plastic stop, by using a knife to cut plastic stop (see figure).

   Make sure the correct side is cut!

    

5. Press the knob back in and test by rotate counter clockwise beyond “0” position. It should be able to rotate to automatic head light position (unmarked position).

   

6. Install head light assembly back to the car in reversing order of the removal.

Coding:

Before you do this coding you must already know how to do coding, please search Google on how to do or where to get the esys software/cable. I only let you know which parameter/ECU you need to make the change.

Note that the auto light sensitivity is depended upon your preference.

The settings are:

• Un_empfindlich = not sensitive (turn on when less light)
• Normal = Default on the car
• Empfindlich = sensitive
• Sehr_empfindlich = very sensitive (turn on even under sun light)

Testing:

1. Automatic Head Light (Need sun light to test!)

   1. Start the car

   2. Switch headlight switch to automatic position (3) see figure

       

   3. The head light should be off under sun light (sensitivity can be changed to your
      preference; see coding section)

   4. Cover the outside windshield in the sensor area with a book/magazine, head light
      should turn on.

   5. Testing of auto head light is done. Turn off the engine

2. Rain sensor testing

   1. Wet the windshield

   2. Start the car

   3. Activate the auto wiper by pressing the button in the wiper lever

      

   4. Spray water on the windshield in the sensor area, the wiper should wipe and stop
      once the water is stopped.

   5. Adjust the sensitivity of the rain sensor and retest the wiping action again to ensure.

   6. Testing is done on rain sensor. Turn off the engine.

3. Solar sensor testing with sun light

   1. Start the engine and turn on the air condition using auto mode. Wait till set
      temperature is reached.

   2. Cove the sensor area and take notice of change in air flow.

   3. Testing is done. Turn off the engine.