OBDeleven modifications

tracktoy

Active Member
Jun 11, 2023
337
243
got a bit more info from Don (DV52) off the forum, hopefully its not something you have had before.

Care should be taken when coding the the airbag module - it can render the vehicle inoperative!!

Anyway, if you look in Adaptations in the 15 Airbag module, you should find a channel called Airbag adaptations-Seat occupied recognition. On cars with the sensor fitted (it's called G128 in the wiring diagram), this channel setting is activated. I'm not sure if a security code will be necessary for the changed setting and if so, what the security code is - security codes for the hex15 module are as rare as rocking-horse ****
:)
!!!

Don

if you need the wiring diagram that can be found on this forum (let me know if you need the location)

good luck with the process
 
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serdar_18fr

Active Member
May 29, 2021
289
1
167
got a bit more info from Don (DV52) off the forum, hopefully its not something you have had before.

Care should be taken when coding the the airbag module - it can render the vehicle inoperative!!

Anyway, if you look in Adaptations in the 15 Airbag module, you should find a channel called Airbag adaptations-Seat occupied recognition. On cars with the sensor fitted (it's called G128 in the wiring diagram), this channel setting is activated. I'm not sure if a security code will be necessary for the changed setting and if so, what the security code is - security codes for the hex15 module are as rare as rocking-horse ****
:)
!!!

Don

if you need the wiring diagram that can be found on this forum (let me know if you need the location)

good luck with the process
Hi, thank you for taking the time to help 🙏

I thoroughly checked all the options in airbag control unit menu in OBDeleven and I know about that adaptation and that I need to use it after installing the seat occupancy sensor.

Last night I tried long coding, using the data I gathered from that Golf comparison and from your garage. I changed the 8th byte, first to 5C and later some other binary combinations of those three different bits. But it never accepted the changes, showing me an error like this: "Function cancelled marginal conditions have not been met"

It's unclear what those marginal conditions are. I tried ignition on or engine on, bonnet open or closed, driver door open or closed, based on what I read before in different forums and guides. Also it might be due to the fact that there is no sensor installed yet and belt latch is not connected so control unit firmware might be expecting signals from those components, but obviously not getting any yet. It would be helpful if I could make this long coding update even if there's no sensor yet. Now I'm not sure that I could do it after installing the sensor.
 

tracktoy

Active Member
Jun 11, 2023
337
243
Hi, thank you for taking the time to help 🙏

I thoroughly checked all the options in airbag control unit menu in OBDeleven and I know about that adaptation and that I need to use it after installing the seat occupancy sensor.

Last night I tried long coding, using the data I gathered from that Golf comparison and from your garage. I changed the 8th byte, first to 5C and later some other binary combinations of those three different bits. But it never accepted the changes, showing me an error like this: "Function cancelled marginal conditions have not been met"

It's unclear what those marginal conditions are. I tried ignition on or engine on, bonnet open or closed, driver door open or closed, based on what I read before in different forums and guides. Also it might be due to the fact that there is no sensor installed yet and belt latch is not connected so control unit firmware might be expecting signals from those components, but obviously not getting any yet. It would be helpful if I could make this long coding update even if there's no sensor yet. Now I'm not sure that I could do it after installing the sensor.
I am afraid i have always stayed away from Airbag control module as it can cause very expensive issue's but I also seem to recall that in many cases you have to use a different diagnostic mode for the coding to be accepted. As I say have very little experience of this unit so can only suggest more research.
 
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serdar_18fr

Active Member
May 29, 2021
289
1
167
Hello everyone,

I have been trying to activate Predictive ACC feature on my 2018 Leon FR.
I already have working ACC & Lane Assist.
Asking some experienced people, I got to know that the radar & camera in my car are compatible with the PACC activation.

I went to a retrofitter, he entered swap codes, did some coding.
Everything seemed to be fine and there was no fault in the system.
Standard ACC still works.
Lane assist works as usual.
Traffic sign recognition by camera and speed limit information by navigation works, I mean, in fusion mode.
Menu options related to PACC are turned on in Driving Assistance menu and they are enabled.
But no "curve/roundabout/speed limit change ahead" message was displayed in the dashboard.
Also ACC didn't set its speed to the actual speed limit automatically.
Long story short, our attempt to activate predictive features didn't work out.

Later I was looking up the entered swap codes and I noticed that one of them might be incorrect.
And I thought that if I re-enter the correct codes, the problem might be solved.

There are a maximum of four swap id positions in the control unit.
One for ACC mode selection, one for ACC expansion feature selection, one for Emergency Assist mode selection and one for Emergency Assist expansion feature selection.

I read somewhere that the swap code had to be created & entered for those 4 FEC IDs as a whole, not one by one.
I did some reading about how to create swap code & enter it on the unit using OBDeleven, so I believe I could do it.

Now what I need to know is whether I need to delete the existing swap codes,
or they would be replaced automatically when I enter the new swap code I created for 4 selected FEC IDs at once.


I would greatly appreciate if experienced people around here share their knowledge with me.

By the way, I would happily pay someone, who knows what they are doing, for their remote assistance, but the problem is that the only diagnostics device I have is OBDeleven and I'm having a hard time to find somebody around here or some local garage who owns a 6154A device (which all retrofitters require to assist remotely) and is willing to rent it to me for an hour or two.

So here I am, trying to take care of my problem myself.

Thanks & best regards,
Serdar
 
Last edited:

serdar_18fr

Active Member
May 29, 2021
289
1
167
No response to my previous post, so I took the risk, did some work and here I am, reporting the results:

Existing swap codes in my radar were the highest possible feature of each category, I think last retrofitter who fiddled with my radar must have done this selection. The one for ACC feature expansion category was predictive ACC + Traffic Jam Assist. This latter one, TJA, works in cars equipped with DSG only. My car is a manual so I thought maybe this incorrect selection was causing the PACC not to work. I created a new swap code, using the FEC code of predictive ACC only as the ACC expansion feature, leaving others as they are.

I was afraid to do something wrong and I wanted to know if I could safely delete an existing swap entry before I tried this, but my inquiry here & research everywhere didn't yield any result so I took the risk and started deleting existing codes one by one, using OBDeleven. At the first one, ACC threw a fault right away but I continued anyway. Then I entered the swap code I created using VIN, VCRN and FEC codes, released it and also entered their last digits in their respective fields in Long Coding. That cleared the faults, I checked the swap status and everything looked fine and I was hopeful.

But it didn't make any difference.
The menu options are still there, switching them on/off is working.
Standard ACC and Lane Assist are working fine, so is the TSR fusion.
But it still doesn't set speed value to actual limit, and doesn't show any curve ahead warnings on dashboard.

Now it's time to leave it to experienced hands, I guess.
 

serdar_18fr

Active Member
May 29, 2021
289
1
167
Hi, thank you for taking the time to help 🙏

I thoroughly checked all the options in airbag control unit menu in OBDeleven and I know about that adaptation and that I need to use it after installing the seat occupancy sensor.

Last night I tried long coding, using the data I gathered from that Golf comparison and from your garage. I changed the 8th byte, first to 5C and later some other binary combinations of those three different bits. But it never accepted the changes, showing me an error like this: "Function cancelled marginal conditions have not been met"

It's unclear what those marginal conditions are. I tried ignition on or engine on, bonnet open or closed, driver door open or closed, based on what I read before in different forums and guides. Also it might be due to the fact that there is no sensor installed yet and belt latch is not connected so control unit firmware might be expecting signals from those components, but obviously not getting any yet. It would be helpful if I could make this long coding update even if there's no sensor yet. Now I'm not sure that I could do it after installing the sensor.

Follow-up on activating seat belt warning on front passenger seat:

I was looking at the official service manuals and found there the coupling point for front passenger seat wirings, under the seat & alongside the door sill, covered by the floor upholstery.

A coupling point is basically an electrical socket with a wiring loom at one side of it, and that wiring loom is connected to necessary parts in different places, like control units, ground points, fuse holders etc. The cables coming out of the related sensors & switches are plugged into those sockets.

The illustration of the front passenger seat coupling point shows three sockets: a 10-pin one for seat heating and other prospective seat control options, a 3-pin one for side airbag and a 4-pin one for seat belt latch contact & seat occupancy sensor.

When I saw that illustration, I somehow got excited and thought that all those three sockets should already be there, I mean, why would VAG engineers take the trouble of having different installations, for just a simple socket. In some of the cars I previously owned, I saw the practice of installing the full wiring loom and leaving some of the sockets unplugged, just waiting there for someone's retrofit project. But it seems VAG doesn't operate that way.

Today I went to a local garage where I became friends with the owner, to get help removing the seat and check the wiring. Then we found out that seat removal was not needed and the coupling point could be accessed when the seat was pulled to its rearmost position & the floor upholstery was lifted at its edge.

Anyway, there are only two sockets at that point in my car, the 10-pin one and the 3-pin one. The last one with 4 pins which I need for this project is not installed unfortunately. If it was, it would be as easy as plugging the front seat belt latch and seat occupany sensor connectors into it.

Now, if I decide to proceed with this project, I just might skip the coupling stuff, cut the connectors from belt latch & sensor, and directly wire them into airbag control unit and ground connections. Or I might also order that 4-pin socket along with sensor, mount it into its position, wire it to the control unit and plug the connectors into it, just like the factory would have done. (By the way, I found the socket part through a quick research, luckily)

After that, I would need :
1. an upholstery expert and get the sensor installed in the seat base
2. an electrics expert to wire the cables (I could do it and it would work, but the wiring job wouldn't end up like an expert would do)
3. coding stuff

As a side note, the seat belt's own cable & connector lays under the seat, unplugged. After seeing VAG's skimpiness with the wirings, I'm surprised that they chose to install a belt latch with an electrical contact. They could have chosen to install one without to save a couple of more pennies there.

Everybody tries to get rid of seat belt warnings, I try to have one more, for my passengers too. Why? First, I find it unbelievable that VAG had skipped such a simple feature which a lot of lower segment cars have, and second, because I love having all the possible features in my car, even if I don't need them or they are not much of a use. I believe my obsession with this can be tolerated among the fellow car enthusiasts :)

Have a nice night & cheers,
Serdar
 
Last edited:

serdar_18fr

Active Member
May 29, 2021
289
1
167
Follow-up on activating seat belt warning on front passenger seat:

I was looking at the official service manuals and found there the coupling point for front passenger seat wirings, under the seat & alongside the door sill, covered by the floor upholstery.

A coupling point is basically an electrical socket with a wiring loom at one side of it, and that wiring loom is connected to necessary parts in different places, like control units, ground points, fuse holders etc. The cables coming out of the related sensors & switches are plugged into those sockets.

The illustration of the front passenger seat coupling point shows three sockets: a 10-pin one for seat heating and other prospective seat control options, a 3-pin one for side airbag and a 4-pin one for seat belt latch contact & seat occupancy sensor.

When I saw that illustration, I somehow got excited and thought that all those three sockets should already be there, I mean, why would VAG engineers take the trouble of having different installations, for just a simple socket. In some of the cars I previously owned, I saw the practice of installing the full wiring loom and leaving some of the sockets unplugged, just waiting there for someone's retrofit project. But it seems VAG doesn't operate that way.

Today I went to a local garage where I became friends with the owner, to get help removing the seat and check the wiring. Then we found out that seat removal was not needed and the coupling point could be accessed when the seat was pulled to its rearmost position & the floor upholstery was lifted at its edge.

Anyway, there are only two sockets at that point in my car, the 10-pin one and the 3-pin one. The last one with 4 pins which I need for this project is not installed unfortunately. If it was, it would be as easy as plugging the front seat belt latch and seat occupany sensor connectors into it.

Now, if I decide to proceed with this project, I just might skip the coupling stuff, cut the connectors from belt latch & sensor, and directly wire them into airbag control unit and ground connections. Or I might also order that 4-pin socket along with sensor, mount it into its position, wire it to the control unit and plug the connectors into it, just like the factory would have done. (By the way, I found the socket part through a quick research, luckily)

After that, I would need :
1. an upholstery expert and get the sensor installed in the seat base
2. an electrics expert to wire the cables (I could do it and it would work, but the wiring job wouldn't end up like an expert would do)
3. coding stuff

As a side note, the seat belt's own cable & connector lays under the seat, unplugged. After seeing VAG's skimpiness with the wirings, I'm surprised that they chose to install a belt latch with an electrical contact. They could have chosen to install one without to save a couple of more pennies there.

Everybody tries to get rid of seat belt warnings, I try to have one more, for my passengers too. Why? First, I find it unbelievable that VAG had skipped such a simple feature which a lot of lower segment cars have, and second, because I love having all the possible features in my car, even if I don't need them or they are not much of a use. I believe my obsession with this can be tolerated among the fellow car enthusiasts :)

Have a nice night & cheers,
Serdar

Another follow-up on the subject:

I purchased the 4-pin socket for the passenger seat coupling point but it's a different shape than I expected. I thought two different connectors (one from the sensor and the other from the belt latch) would plug into it but this socket has its own 4-pin inside part so some interim cables are needed as I don't want to cut original connectors of the sensor and the belt latch. Today I went to my local garage and get one of those cables made for me and I connected it to the sensor. Now I have an extended cable coming from the sensor with a 4-pin inner part at the other end. It will be plugged into the 4-pin connector at the coupling point. Remaining 2 pins will be used for belt latch, which will be extended later in the same manner. Monday I will be going to the upholstery shop to get the sensor installed. The big question mark is whether the airbag control unit would let us to change long coding & adaptations after it gets the signal from the sensor & belt; the whole work could go to trash if it wouldn't.

Cheers,
Serdar
 

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serdar_18fr

Active Member
May 29, 2021
289
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167
Another follow-up on the subject:

I purchased the 4-pin socket for the passenger seat coupling point but it's a different shape than I expected. I thought two different connectors (one from the sensor and the other from the belt latch) would plug into it but this socket has its own 4-pin inside part so some interim cables are needed as I don't want to cut original connectors of the sensor and the belt latch. Today I went to my local garage and get one of those cables made for me and I connected it to the sensor. Now I have an extended cable coming from the sensor with a 4-pin inner part at the other end. It will be plugged into the 4-pin connector at the coupling point. Remaining 2 pins will be used for belt latch, which will be extended later in the same manner. Monday I will be going to the upholstery shop to get the sensor installed. The big question mark is whether the airbag control unit would let us to change long coding & adaptations after it gets the signal from the sensor & belt; the whole work could go to trash if it wouldn't.

Cheers,
Serdar
And finally, happy ending.

Weight sensor was installed in the front passenger seat. When seat was removed for this installation, I found that the factory had installed a belt latch without a cable/connector but installed a short wiring harness from the seat to the coupling point near the side sill. They opted to cut some cost using a belt latch without a cable but they didn't care about the cost of the wiring harness under the seat. Strange practice by the factory.

Anyway, I bought a proper belt latch with cable/connector from my local SEAT dealer, got the seat removed again, replaced the existing belt latch with the new one and plugged its connector to the wiring harness factory left there for me.

Then I got a new 4-pin harness made for the wiring from coupling point to the airbag control unit (2 pins for belt latch & 2 pins for weight sensor), laid the harness and connected it to unit's connector.

Control unit immediately fired three faults: One for the belt latch, one for the weight sensor and a vehicle/unit mismatch fault. It receives signals from related pins but those signals are unexpected according to its configuration, obviously.

Then, using the official on-line parts catalog software, I looked for a vehicle with identical model year & hardware as mine, with the only difference being fitted with a passenger seat belt warning feature. This proved not so difficult because almost all cars in Europe were fitted with this important safety feature.

We downloaded the airbag control unit dataset of that vehicle and uploaded it to the one in my car. This allowed us to do long coding related to passenger seat airbag and weight sensor activation. Prior to that, my attempts to code those changes using OBDeleven were failing because existing dataset was not compatible with the new features I was trying to activate.

Anyway, we made the changes and this helped clear all the faults. Also I checked the live data from the sensor & contact and they were all showing correct states. Then I got an employee from the retrofitter shop as a passenger, we did a test drive and everything worked perfectly. My car now has the simple but important feature of passenger seat belt warning.

Thanks for reading & cheers.

Sent from my 23013PC75G using Tapatalk
 
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