sensitivity of the rain (light) sensor

[ZERO922]

Is it possible to adjust the sensitivity of the rain (light) sensor by coding?

[FlyingLow78]

Yes, however I haven’t noticed a difference after adjusting it with BimmerCode. I’ve already had the sensor replaced on my ‘18 M3, but the low speed performance is still sub-optimal, and the rest of the time it’s barely tolerable. Setting it to Very Sensitive didn't seem to make a difference.

[ZERO922]

Thank you so much!

Can't feel the difference ...

[FlyingLow78]

It has to be an issue with the latest generate of software, because my 2015 M3 had wipers that worked like they were wired into my brain. Specifically, I think it’s an issue with the sensitivity at low speed - the engineers thought we wouldn’t need to be able to see when we weren’t moving.

[CanAutM3]

Originally Posted by FlyingLow78

Yes, however I haven’t noticed a difference after adjusting it with BimmerCode. I’ve already had the sensor replaced on my ‘18 M3, but the low speed performance is still sub-optimal, and the rest of the time it’s barely tolerable. Setting it to Very Sensitive didn't seem to make a difference.

My understanding is that the coding line only affects the auto-headlamp sensitivity. The wiper sensitivity is already adjustable on the wiper stalk.

[FlyingLow78]

RLS_DEF_FLC_SCHWELLWERT_SATZ is the FEM value that gets adjusted in BimmerCode. I’m not sure what the abbreviations mean, but the rest translates to “threshold rate”.

Stuff I’d pay good money to get back:

Auto wipers that work at low speed
Triple turn signals that blink five times
Auto all-around cameras in reverse

[ZERO922]

If the headlamps are set to automatic, the headlamps will not disappear even if you exit the tunnel.
Does it disappear when the sensitivity is changed?

Triple turn signal flashing 5 times
Yeah, this doesn't work either.

[backagain]

Originally Posted by FlyingLow78

RLS_DEF_FLC_SCHWELLWERT_SATZ is the FEM value that gets adjusted in BimmerCode. I’m not sure what the abbreviations mean, but the rest translates to “threshold rate”.

Stuff I’d pay good money to get back:

Auto wipers that work at low speed
Triple turn signals that blink five times
Auto all-around cameras in reverse

The 5-tick turn signals can be coded, or it doesn't work on the '18 models?
FEM_BODY 3060 BLINKZYKLEN_ANZAHL_TIPP

[FlyingLow78]

Originally Posted by backagain

The 5-tick turn signals can be coded, or it doesn't work on the '18 models?
FEM_BODY 3060 BLINKZYKLEN_ANZAHL_TIPP

It doesn’t work on ‘18s.

[CanAutM3]

Originally Posted by ZERO922

If the headlamps are set to automatic, the headlamps will not disappear even if you exit the tunnel.
Does it disappear when the sensitivity is changed?

Triple turn signal flashing 5 times
Yeah, this doesn't work either.

With the stock setting, I found that the headlights would turn on too eraly and not readily turn off when I deemed there was sufficient natural lighting. By reducing the sensitivity setting, I now find they operate much more to my liking, turning on an off where it makes sense to me.

[ZERO922]

Do you lower the sensitivity setting?

[FlyingLow78]

I'm reviving this thread because it's still an issue. The auto wipers use an infrared light source to detect rain on the windshield. A piece of foil can be used to reflect the light to simulate maximum rain saturation.

The dealership has already replaced the rain-light sensor (RLS), but it made no difference whatsoever, so I suspect it's a coding issue. In OEM configuration, when sent to auto, the wipers are inactive until a certain speed is reached, after which they work according to the sensitivity adjustment on the stalk.

With the car stationary and no water detected, they never wipe, so you can leave them in auto all the time. As water is detected, they wipe variably up to about a maximum one second delayed interval.

In FEM_BODY, 3130 RainLightSensor, then REGENSENSOR_INTERVAL, the normal werte value is 00. Changing it to 01 disregards the rain sensor and it will wipe once every ten seconds while in auto with the vehicle stationary. I also tried wertes 02 and 03, which just generated errors.

My next step is to examine RLS_KONFIG_RLS_GESCHW (RLS speed). The normal werte is 00, so I tried 01 and 02. Neither made a difference to wiper sensitivity while stationary, but I am not able to test while the vehicle is moving because it's not raining at this moment. I will test it once it starts raining again.

If anyone has familiarity with settings under the following subfolders, it may be helpful:

RLS_TYP_FRONTSCHEIB (RLS front windshield)
RLS_TYP_FAHRZEUG (RLS vehicle)
RLS_LENKUNG (RLS steering)
RLS_KONFIG_REGEN_AUS (RLS rain out?)
RLS_BS_KORREKTUR_INFO
RLS_DEF_FLC_SCHWELLWERT_SATZ (RLS threshold set, which appears to only adjust auto headlight sensitivity)

[gspannu]

Originally Posted by FlyingLow78

I'm reviving this thread because it's still an issue. The auto wipers use an infrared light source to detect rain on the windshield. A piece of foil can be used to reflect the light to simulate maximum rain saturation.

The dealership has already replaced the rain-light sensor (RLS), but it made no difference whatsoever, so I suspect it's a coding issue. In OEM configuration, when sent to auto, the wipers are inactive until a certain speed is reached, after which they work according to the sensitivity adjustment on the stalk.

With the car stationary and no water detected, they never wipe, so you can leave them in auto all the time. As water is detected, they wipe variably up to about a maximum one second delayed interval.

In FEM_BODY, 3130 RainLightSensor, then REGENSENSOR_INTERVAL, the normal werte value is 00. Changing it to 01 disregards the rain sensor and it will wipe once every ten seconds while in auto with the vehicle stationary. I also tried wertes 02 and 03, which just generated errors.

My next step is to examine RLS_KONFIG_RLS_GESCHW (RLS speed). The normal werte is 00, so I tried 01 and 02. Neither made a difference to wiper sensitivity while stationary, but I am not able to test while the vehicle is moving because it's not raining at this moment. I will test it once it starts raining again.

If anyone has familiarity with settings under the following subfolders, it may be helpful:

RLS_TYP_FRONTSCHEIB (RLS front windshield)
RLS_TYP_FAHRZEUG (RLS vehicle)
RLS_LENKUNG (RLS steering)
RLS_KONFIG_REGEN_AUS (RLS rain out?)
RLS_BS_KORREKTUR_INFO
RLS_DEF_FLC_SCHWELLWERT_SATZ (RLS threshold set, which appears to only adjust auto headlight sensitivity)

Watching this keenly... This may finally be a solution to having a better auto-wiper setting coded.

Thanks for your effort....

[FlyingLow78]

TLDR: I tried a bunch of changes and nothing made the wipers more responsive, but it may be due to a testing procedure error. I have a plan to re-test and focus on certain areas. I also calibrated the sensor with an artificially high infrared emission to see if it increases the sensitivity. The last step will be to shoot power and ground for the sensor.

OK, so I had a nice, steady rain yesterday when I got home. I took the car out and left it connected to the laptop so I could make changes and test them immediately. Nothing profound came of this because I believe I need to turn the car off and back on after coding FDL.

TIS: "Vehicles with Front Electronic Module (FEM) or Body Domain Controller (BDC):

At each new start, the front electronic module (FEM) or body domain controller (BDC) sends a configuration telegram for vehicle-specific configuration of the rain-light-solar-condensation sensor.

The automatic driving lights control provides an encoding possibility to change the sensitivity settings (Japanese version: changed sensitivity settings).

TIS has a lot of explanations about the below information.

In E-Sys, here are the module options from FEM_BODY, 3130:

RLS_LIN_VAR (possibly linear variability? The translation works - lineare Variabilität. Or perhaps something related to the LIN bus.)
Choices (which appear to be different types of sensors):

- RLSBS (default)
- Not active
- RLS
- RLSBSoH
- RLSS
- RLSS-H
- SBS
- SolarSensor

RLS_TYP_WISCHSYSTEM (wiping system type)
Choices (I tried changing this and it made no difference, but I should retest with power cycle after coding):

- 2-stage (default)
- more levels

RLS_TYP_FRONTSCHEIB (RLS front windshield, which appear to be different types of sensor generations. TIS: "At the moment, third and fourth generation sensors are installed.")
It may be worth changing this to see if one windshield increases the sensitivity more than the default.
Choices:

- Serienscheibe (serial disc? default)
- Frontscheibe 3 (windscreen 3)
- Frontscheibe 4 (windscreen 4)
- Frontscheibe Sicherheitsfzg (safety windscreen?)
- Klimacomfort (comfort climate)

RLS_TYP_FAHRZEUG (vehicle type)
Choices:

- LK (default)
- Fxx (I might try this)
- MCV
- Invalid signal
- UKL
- XNF

RLS_LENKUNG (steering L/R)
Choices:

- linkslenker (LHD, default)
- rechtslenker (RHD)

RLS_KONFIG_REGEN_AUS (RLS rain out?)
Choices:

- Active
- Inactive

RLS_BS_KORREKTUR_INFO (correction info)
Choices (I tried each of these, but it made no difference, possibly because I didn't cycle power to the car after coding):

- No correction (default)
- Correction sentence 1
- Correction sentence 2

RLS_DEF_FLC_SCHWELLWERT_SATZ (RLS threshold set, which discussion suggest only adjusts auto headlight sensitivity)
Choices:

- Normal (probably default)
- Sensitive
- Very sensitive
- Insensitive
- Daytime running lights

OK, so besides testing the items in bold, I can look at the actual functionality of the system. It appears to work on a series of transistorized integrated circuits, but power and ground can still be shot. Calibration techniques can also be explored.

Sensor arrangement. TIS: Rain sensor:

- The rain sensor consists of three individual sensors that are arranged in a semicircle around the driving light sensor and pick up the precipitation quantity on the windscreen. The transmit diodes and the receiver diodes function in the infrared range (which will be important later). The three transmit diodes emit infrared light that is routed via the optical element to the windscreen. If the windscreen is completely dry and clean in the area of the optical element, the infrared light is fully reflected to the three receiver diodes.

If there is precipitation or dirt in the area of the optical element on the windscreen, the infrared light is refracted. This means that only part of the infrared light is reflected to the receiver diodes. The reflected light quantity is thus the measurement of the intensity of the precipitation in the area of the optical element. On the basis of the missing light quantity, the evaluation electronics detects the windscreen's degree of wetness and requests wiper activity that is appropriate to this (e.g. one wipe cycle, continuous wipe or intermittent operation at different wiper frequencies).

OK, so theoretically, if I add infrared light during the calibration of the sensor, it will adopt a higher threshold for refraction (i.e. more sensitive). Where can I get an infrared source? There's a small one in most TV remote controls. Hair dryers are another option.

Using a TV remote, I pressed the remote's infrared emitter against the rain sensor and ran the calibration sequence in ISTA. Hopefully it will require less refraction to engage the wipers, and still be within the tolerances of the sensitivity knob.






I can also shoot the wires to verify good power and ground. The sensor operates on 9-14 volts. Looking at the schematic, the ground for the sensor is located in the passenger footwell. Voltage can easily be shot at the sensor.

[gspannu]

Originally Posted by FlyingLow78

TLDR: I tried a bunch of changes and nothing made the wipers more responsive, but it may be due to a testing procedure error. I have a plan to re-test and focus on certain areas. I also calibrated the sensor with an artificially high infrared emission to see if it increases the sensitivity. The last step will be to shoot power and ground for the sensor.

Read your complete post with great interest...
You are doing us all a big favour by experimenting with all these settings and trying to find a solution. THANK YOU.
Eagerly await your results post power cycle...

[FlyingLow78]

Here's today's summary.

I performed a standard calibration of the rain sensor exactly per ISTA+ last night right before I went to bed. The wipers performed horribly yesterday, so I wanted to see how good I could make the stock configuration work first, before messing around with an augmented infrared source.

Lesson #1: Adjusting RLS_DEF_FLC_SCHWELLWERT_SATZ absolutely adjusts wiper sensitivity. I started the drive with the RLS set to "insensitive", and they were oblivious at any rain at any speed. I stopped and set them to "very sensitive", turned the car off, opened and closed the door, and restarted the car.

The wipers now worked, and the system didn't seem to mind that I had it set to Windshield 4. In torrential rain they did what they were supposed to, and worked at maximum speed with the stalk at max sensitivity.

I stopped and switched the windshield setting to Klimakomfort (details here), and this type of glass is designed to reject infrared heating, so it implies that the rain sensor will be set to a higher sensitivity to compensate. After turning the car off/on, I tested again.

The wipers worked pretty well in intense rain, about on par with the Windshield 4 setting, but the test was only about 20 minutes and at highway speeds. I still had to use the highest stalk sensitivity setting, and I didn't get to adequately test the low speed performance, but my initial impression is that they work better than before. There was even a point where I said to myself, "OK, wipers...settle down," because they were going too fast for the volume of water.

Lesson #2: Do not adjust REGENSENSOR_INTERVAL (RLS interval). Active means the wipers sweep once every 10 seconds at low speed, and it appeared the rain sensor was completely ignored otherwise. Leave it nicht_aktiv (not active).

The best results so far have been achieved with a fresh sensor calibration through ISTA+, and nominal settings from the factory except RLS_DEF_FLC_SCHWELLWERT_SATZ to sehr_empfindlich (very sensitive), and RLS_TYP_FRONTSCHEIB set to KlimaKomfort.

Up next: testing Windshield 3 and Safety Windshield. Also need to test RLS_TYP_WISCHSYSTEM set to "more levels" to see if it resolves the low speed inactivity problem.

[gspannu]

Originally Posted by FlyingLow78

Here's today's summary.

I performed a standard calibration of the rain sensor exactly per ISTA+ last night right before I went to bed. The wipers performed horribly yesterday, so I wanted to see how good I could make the stock configuration work first, before messing around with an augmented infrared source.

Lesson #1: Adjusting RLS_DEF_FLC_SCHWELLWERT_SATZ absolutely adjusts wiper sensitivity. I started the drive with the RLS set to "insensitive", and they were oblivious at any rain at any speed. I stopped and set them to "very sensitive", turned the car off, opened and closed the door, and restarted the car.

The wipers now worked, and the system didn't seem to mind that I had it set to Windshield 4. In torrential rain they did what they were supposed to, and worked at maximum speed with the stalk at max sensitivity.

I stopped and switched the windshield setting to Klimakomfort (details here), and this type of glass is designed to reject infrared heating, so it implies that the rain sensor will be set to a higher sensitivity to compensate. After turning the car off/on, I tested again.

The wipers worked pretty well in intense rain, about on par with the Windshield 4 setting, but the test was only about 20 minutes and at highway speeds. I still had to use the highest stalk sensitivity setting, and I didn't get to adequately test the low speed performance, but my initial impression is that they work better than before. There was even a point where I said to myself, "OK, wipers...settle down," because they were going too fast for the volume of water.

Lesson #2: Do not adjust REGENSENSOR_INTERVAL (RLS interval). Active means the wipers sweep once every 10 seconds at low speed, and it appeared the rain sensor was completely ignored otherwise. Leave it nicht_aktiv (not active).

The best results so far have been achieved with a fresh sensor calibration through ISTA+, and nominal settings from the factory except RLS_DEF_FLC_SCHWELLWERT_SATZ to sehr_empfindlich (very sensitive), and RLS_TYP_FRONTSCHEIB set to KlimaKomfort.

Up next: testing Windshield 3 and Safety Windshield. Also need to test RLS_TYP_WISCHSYSTEM set to "more levels" to see if it resolves the low speed inactivity problem.

Thank you.... I guess you are nearly there at cracking the mystery !

[FlyingLow78]

Today I tested RLS_TYP_WISCHSYSTEM set to "more levels" and it made the wipers worse, so I went back to the 2-stage (2_stufen) setting.

After an off/on power cycle, I drove back and forth through one of the towns near me for ~30 minutes trying to isolate the stage-1/stage-2 crossover point, and I think it's around 30 kph. It's difficult, though, because the wipers don't respond instantly and somewhat average the rainfall detected over a period to smooth out variations in the wiper speed.

I'm going to say it's fixed. The best results were achieved with a standard sensor calibration through ISTA+, and default coding from the factory, except RLS_DEF_FLC_SCHWELLWERT_SATZ set to sehr_empfindlich (very sensitive), and RLS_TYP_FRONTSCHEIB set to KlimaKomfort. My ideal setting is now somewhere just below the most sensitive setting, since max sensitivity causes the wipers to go crazy sometimes.

[gspannu]

Originally Posted by FlyingLow78

Today I tested RLS_TYP_WISCHSYSTEM set to "more levels" and it made the wipers worse, so I went back to the 2-stage (2_stufen) setting.

After an off/on power cycle, I drove back and forth through one of the towns near me for ~30 minutes trying to isolate the stage-1/stage-2 crossover point, and I think it's around 30 kph. It's difficult, though, because the wipers don't respond instantly and somewhat average the rainfall detected over a period to smooth out variations in the wiper speed.

I'm going to say it's fixed. The best results were achieved with a standard sensor calibration through ISTA+, and default coding from the factory, except RLS_DEF_FLC_SCHWELLWERT_SATZ set to sehr_empfindlich (very sensitive), and RLS_TYP_FRONTSCHEIB set to KlimaKomfort. My ideal setting is now somewhere just below the most sensitive setting, since max sensitivity causes the wipers to go crazy sometimes.

Is the sensor calibration a must?

Reason I ask is that I have ESys but do not have ISTA+... (never used it either... on my todo list but have never gotten to it)

[FlyingLow78]

I don't think it's a must, and it can be done after the E-Sys coding if the performance still doesn't improve. I still haven't legitimately tried an augmented infrared calibration, either. I'd like to have a better source than my TV remote...perhaps a pyrometer?

[gspannu]

Originally Posted by FlyingLow78

I don't think it's a must, and it can be done after the E-Sys coding if the performance still doesn't improve. I still haven't legitimately tried an augmented infrared calibration, either. I'd like to have a better source than my TV remote...perhaps a pyrometer?

I’m going to give it a go over the weekend... and hopefully it will rain (well it always rains in the UK anyway !) to test it out...

[FlyingLow78]

Good luck!