RHLS sensor coding

[64bittz]

Hi all,
Following advice on this forum, i started doing a proper retrofit for auto lights for my pre facelift seat leon mk3 st. The car had no climatronic, so the rearview mirror didn’t have the mounting point for the sensor. I used a plastic adapter from aliexpress to attach to the windshield and provide a mounting point for the sensor. From the same kit i routed the wiring harness to the bcm pin 28, supply and ground. I tried doing some coding that i found online but the auto lights and wipers don’t work. I see from trouble codes that the BCM sees the sensor correctly, so the connection is fine, i only need the correct coding.

the sensor part number is 81D955547B. I have a elm327 device and the Car Scanner OBD ios app. I restored all coding to original so that i start from where i was before.

also, the cable bundle going to the light switch has 9 cables, so from what i understand i don’t need to do that particular routing to the bcm.

has anyone ever tried retrofitting the RHLS in this situation? What coding did work for you?

one thing that i did was accidentally damage the gel pad, so i removed it for the time being and ordered a replacement. Can it be the culprit?

Below are attached images of the kit

 

[serdar_18fr]

has anyone ever tried retrofitting the RHLS in this situation? What coding did work for you?

one thing that i did was accidentally damage the gel pad, so i removed it for the time being and ordered a replacement. Can it be the culprit?

I don't have an immediate answer for your question, but I have a question for you:

Did you look at the live data from the sensor ?

I mean, what is the status of sensor when it sees the daylight, and also what is the status of sensor when you obstructed the daylight by putting your hand on the windscreen where it resides? Did you ever try that and check the live data at the same time?

I'm asking this because it would at least show whether the sensor is working or not, or whether the correct status values are received by BCM.

 

[64bittz]

I don't have an immediate answer for your question, but I have a question for you:

Did you look at the live data from the sensor ?

I mean, what is the status of sensor when it sees the daylight, and also what is the status of sensor when you obstructed the daylight by putting your hand on the windscreen where it resides? Did you ever try that and check the live data at the same time?

I'm asking this because it would at least show whether the sensor is working or not, or whether the correct status values are received by BCM.

Hi thanks for replying. I have no idea how to check the live data from the sensor. I can’t even see if it’s recognised from the app i’m using. When i do a scan of the system it only gets the BCM, not the sensor or other things.
I did however confirm that communication is happening because when i enabled it through adaptations and left it disconnected, i could see a “failure to communicate with rhls sensor” trouble code each time i restart the car. When i connected it, the trouble code was archived. I repeated a couple of times and confirmed that it gets archived when the sensor is connected and pops up when the sensor is disconnected.

also, i purchased a used OEM 5Q0955547B, which is a different code than the aliexpress one, and it’s the one that all tutorials target so we’ll see if it’s that. I’ll report back in a couple of days

 

[cairus]

STG 09 > Coding > …
> Byte 06 > Set bits 0-1 to 02
> Byte 07 > Activate bit 5

By VfL Car

STG 09 > Access authorization: 31347 > Adjustment > …
> Channel "Comfort Lighting - Coming Home Installation Status" > Set value to "automatic"
> Channel "Comfort Lighting - Menu Control Coming Home Factory Setting" > Set value to "active"
> Channel "Comfort Lighting - Menu Setting Coming Home" > Set value to "30 s"

Channel "Comfort Lighting - Coming Home Lights" > Set value to "dipped beam"
> Channel "Comfort Lighting - Coming Home Switch-on Event" > Set value to "Driver door"
> Channel "Comfort Lighting - Brightness Threshold Infrared Measurement" > Set value to "12 lx" or "3"
> Channel "Comfort Lighting - Leaving Home Installation Status" > Set value to "enabled" Set
> Channel "Comfort Lighting - Menu Control Leaving Home Activation via BAP" > Set value to "active"
> Channel "Comfort Lighting - Menu Setting Leaving Home Time via BAP" > Set value to "30 s"
> Channel "Comfort Lighting - Brightness Threshold Forward Measurement" > Set value to "46400 lx" or "112"


All information without guarantee and liability for correctness

 

[serdar_18fr]

Hi thanks for replying. I have no idea how to check the live data from the sensor. I can’t even see if it’s recognised from the app i’m using. When i do a scan of the system it only gets the BCM, not the sensor or other things.
I did however confirm that communication is happening because when i enabled it through adaptations and left it disconnected, i could see a “failure to communicate with rhls sensor” trouble code each time i restart the car. When i connected it, the trouble code was archived. I repeated a couple of times and confirmed that it gets archived when the sensor is connected and pops up when the sensor is disconnected.

also, i purchased a used OEM 5Q0955547B, which is a different code than the aliexpress one, and it’s the one that all tutorials target so we’ll see if it’s that. I’ll report back in a couple of days

Only the control units have the ability to communicate with diagnostics devices so it is normal that the diagnostics device recognizes only control units, not the connected sensors.

The app you are using most probably have a live data display feature for each control unit, and that includes the BCM (09 - Central Electrics) When you select the BCM from the list of control units, you should see a live data (feature name can be different) option in a menu somewhere. This allows you to see the actual values of tens or hundreds of different parameters in the unit itself or collected from connected sensors.

This is important because rain/light sensors need special windscreens that have an opening (like a hole in a dark area on the upper section of the glass) for the sensor to work properly. In the past I made a retrofit exactly like this in a different brand car and I had to replace my standard windscreen with the one that's suitable for a rain/light sensor. I'm not sure that's also the case with Leon but most probably it is. If you didn't replace the windscreen, you might never get it working properly and that's why I asked about your current situation with live data.

Hope this is clear enough. Please feel free to keep the dialog going & cheers.


Sent from my 23113RKC6G using Tapatalk

 

[64bittz]

Only the control units have the ability to communicate with diagnostics devices so it is normal that the diagnostics device recognizes only control units, not the connected sensors.

The app you are using most probably have a live data display feature for each control unit, and that includes the BCM (09 - Central Electrics) When you select the BCM from the list of control units, you should see a live data (feature name can be different) option in a menu somewhere. This allows you to see the actual values of tens or hundreds of different parameters in the unit itself or collected from connected sensors.

This is important because rain/light sensors need special windscreens that have an opening (like a hole in a dark area on the upper section of the glass) for the sensor to work properly. In the past I made a retrofit exactly like this in a different brand car and I had to replace my standard windscreen with the one that's suitable for a rain/light sensor. I'm not sure that's also the case with Leon but most probably it is. If you didn't replace the windscreen, you might never get it working properly and that's why I asked about your current situation with live data.

Hope this is clear enough. Please feel free to keep the dialog going & cheers.


Sent from my 23113RKC6G using Tapatalk

I didn’t replace the windscreen, but the sensor is facing just glass, not the black dots so it’s basically like it’s an oem install, just that it’s a little different position. I have attached an image to the first post and you can see what i did. Basically the mounting thing goes around the rearview mirror install point and provides an anchor point for the sensor to be placed even without the correct windshield. The only difference is that it’s place 5cm below where the original position would be.

regarding live data, i have a “Sensors” tab, but i only saw temperatures, pressure and stuff so i didn’t look too much into it. I’ll have an in depth look tomorrow and check if the value is actually there.

 

[64bittz]

STG 09 > Coding > …
> Byte 06 > Set bits 0-1 to 02
> Byte 07 > Activate bit 5

By VfL Car

STG 09 > Access authorization: 31347 > Adjustment > …
> Channel "Comfort Lighting - Coming Home Installation Status" > Set value to "automatic"
> Channel "Comfort Lighting - Menu Control Coming Home Factory Setting" > Set value to "active"
> Channel "Comfort Lighting - Menu Setting Coming Home" > Set value to "30 s"

Channel "Comfort Lighting - Coming Home Lights" > Set value to "dipped beam"
> Channel "Comfort Lighting - Coming Home Switch-on Event" > Set value to "Driver door"
> Channel "Comfort Lighting - Brightness Threshold Infrared Measurement" > Set value to "12 lx" or "3"
> Channel "Comfort Lighting - Leaving Home Installation Status" > Set value to "enabled" Set
> Channel "Comfort Lighting - Menu Control Leaving Home Activation via BAP" > Set value to "active"
> Channel "Comfort Lighting - Menu Setting Leaving Home Time via BAP" > Set value to "30 s"
> Channel "Comfort Lighting - Brightness Threshold Forward Measurement" > Set value to "46400 lx" or "112"


All information without guarantee and liability for correctness

I can do long coding with my current setup. The other adaptations i’m not too sure. They are surely not called like that.
Are they for obd eleven or vcds?

 

[serdar_18fr]

I didn’t replace the windscreen, but the sensor is facing just glass, not the black dots so it’s basically like it’s an oem install, just that it’s a little different position. I have attached an image to the first post and you can see what i did. Basically the mounting thing goes around the rearview mirror install point and provides an anchor point for the sensor to be placed even without the correct windshield. The only difference is that it’s place 5cm below where the original position would be.

regarding live data, i have a “Sensors” tab, but i only saw temperatures, pressure and stuff so i didn’t look too much into it. I’ll have an in depth look tomorrow and check if the value is actually there.

Alright, I hope just facing the glass would be enough for the sensor to work. I mean, a windscreen is not just glass but also have some kind of plastic layer in between to prevent it from shattering. I don't want to mislead you but save this information in a corner of your mind and try to test the sensor somehow, whether it really sends the proper data to the control unit.



Sent from my 23113RKC6G using Tapatalk

 

[64bittz]

Alright, I hope just facing the glass would be enough for the sensor to work. I mean, a windscreen is not just glass but also have some kind of plastic layer in between to prevent it from shattering. I don't want to mislead you but save this information in a corner of your mind and try to test the sensor somehow, whether it really sends the proper data to the control unit.



Sent from my 23113RKC6G using Tapatalk

That is something i did not think about. So you are saying that there might be some layer in that region where the sensor is on equipped cars? Otherwise i can't see any reason for why the 2 windscreens should be any different because the protection layers should be in both of them. From my understanding the windscreen has to be changed because the glue they use to attach the mirror to the glass is basically impossible to remove. I’m not an expert though.
I really do hope the windscreens are the same or that at least i can compensate by changing sensitivity

 

[serdar_18fr]

That is something i did not think about. So you are saying that there might be some layer in that region where the sensor is on equipped cars? Otherwise i can't see any reason for why the 2 windscreens should be any different because the protection layers should be in both of them. From my understanding the windscreen has to be changed because the glue they use to attach the mirror to the glass is basically impossible to remove. I’m not an expert though.
I really do hope the windscreens are the same or that at least i can compensate by changing sensitivity

Something like that but I'm saying the opposite. The laminated windscreen has a whole layer sandwiched between two sheets of glass, and probably no layer in a small opening where the sensor supposed to be, otherwise it might prove detrimental to the sensor's operation. I always thought the difference between two types of windscreens is something like this but I might be overthinking it. If you manage to get it working like this, you'll prove that I was wrong


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[64bittz]

Something like that but I'm saying the opposite. The laminated windscreen has a whole layer sandwiched between two sheets of glass, and probably no layer in a small opening where the sensor supposed to be, otherwise it might prove detrimental to the sensor's operation. I always thought the difference between two types of windscreens is something like this but I might be overthinking it. If you manage to get it working like this, you'll prove that I was wrong


Sent from my 23113RKC6G using Tapatalk

Crap, i really hope i can prove you wrong because i wouldn’t like if that is really the case. Normally i would say that since this kit exists it shouldn’t be the case, but we know aliexpress. You’re not overthinking. Fingers crossed that i can prove you wrong since i spent quite some money on this retrofit.