Trouble Pairing Cheap Remotes – Same Code?

[kevinp]

Hi all,

I recently bought 3 remote keys from AliExpress, and I've had the blades cut and the transponders programmed using VVDI2. So far, so good, the transponders work fine, and frequency checks for the remotes show they’re transmitting correctly.

However, I'm struggling to code the remotes. Here's where it gets weird: all three remotes seem to have the same "code," which makes me wonder about how the remote matching process actually works. Does the car actively program the remote, or does the remote come pre-coded and the car just validates it?

Interestingly, when I paired one remote, the second one briefly appeared to "work", almost as if the car detected that both remotes had identical codes and then rejected them. When this happened, VCDS showed a BCM error related to incorrect remote pairing.

I do have a working remote (from a previous locksmith) that I can always re-pair successfully, so I know the adaptation process works when the remote is legit. Given that I only paid €12 for all three (and the blades, shells, and transponders are fine), it’s not a big loss, but I’d really like to understand what’s going on. Am I doing something wrong during the remote adaptation, or are these boards just junk?

Appreciate any insight or experiences you can share!

[ciclo]

Hi,



You must exit the procedure and start again with the next remote.
New value = 0 = ...always.
1.2.3 =

[kevinp]

Thank you so much Ciclo!
I'll try with my current remotes first, though I've ordered Xhorse remotes just in case. Since I'm not familiar with how remote matching works internally, I can't be 100% certain the remotes are the issue, but I have read "similar" cases where people could open other cars with their remote (it wasn't VAG, so it may be different).
What a pleasure to have you on my thread, I've been learning so much about PQ25 retrofits from your posts!

[ciclo]

Hi Kevinp, thank you for your kind words.
I've adapted cheap remotes from Ali without any problems. I even had one I'd stored for many years, which I did to transplant the PCB to another case.
With VVDI, you can generate the transponder for these cheap remotes, even if it's already generated for ID48. Read the original transponder and you'll be able to choose the transponder generation for "SEAT".

Xhorse remotes are of very good quality compared to the cheap generic ones.

[kevinp]

Hi!
I've just tried adapting some AliExpress remotes following the exact procedure that was posted earlier, and I'm running into some weird issues.
Here's what happened:

I successfully removed all learned remotes (verified by testing each one)
Re-learned my original working remote - no problems
Learned the 1st AliExpress remote - tested it right after learning and it opened/closed fine
Learned the 2nd AliExpress remote - tested it right after learning and it opened/closed fine too

At this point I was feeling pretty good about the whole thing. I left the car and did some testing:

Original remote: Still works perfectly
1st AliExpress remote: Opens/closes but can't do the comfort function to close windows (wtf? btw the red light doesn't blink on the remote, as it does on the already working one)
Then tried the 2nd AliExpress remote: Completely stopped working (won't open or close)
Went back to the 1st AliExpress remote: Now it doesn't work either!

Only my original remote still functions. I connected VCDS and found some faults (ignoring the "terminal open" fault since I just upgraded the BCM and haven't wired the lights through it yet).

Code: Select all

                Address 09: Cent. Elect.       Labels: 7E0-937-BCM-V1.clb
Control Module Part Number: 7E0 937 090 E    HW: 7E0 937 090 E
  Component and/or Version: BCM PQ25 Max4 H84 0771
           Software Coding: 38982DA80C210100002000302C091C800F0840FF60000C00200000000000
            Work Shop Code: WSC 12345 123 12345
                      VCID: 2D51BCB3741137E519-8078
3 Faults Found:

01516 - Terminal 30; Left 
            011 - Open Circuit
             Freeze Frame:
                    Fault Status: 01101011
                    Fault Priority: 3
                    Fault Frequency: 26
                    Reset counter: 9
                    Mileage: 177649 km
                    Time Indication: 0
                    Date: 2063.14.31
                    Time: 16:32:39

00927 - Terminal 30 (Right) 
            011 - Open Circuit
             Freeze Frame:
                    Fault Status: 01101011
                    Fault Priority: 3
                    Fault Frequency: 26
                    Reset counter: 9
                    Mileage: 177649 km
                    Time Indication: 0
                    Date: 2063.14.31
                    Time: 16:32:39

02660 - Radio Remote Control not Matched/Adapted 
            000 - -
             Freeze Frame:
                    Fault Status: 01100000
                    Fault Priority: 3
                    Fault Frequency: 2
                    Reset counter: 9
                    Time Indication: 0

[ciclo]

Have you tried different CR2032 batteries?
There are some battery brands that cause problems even when they're new.

I recommend Maxell or Panasonic... work wonderfully.
They're usually available at local discount stores, you'll most likely find them locally. 1eur per battery.


---
Edit.

Just out of curiosity: (it doesn't have to be related to this issue)
When you swapped the BCM/GW, did you code the new GW with the old coding from the previous GW?


BCM PQ25 Max4 H84 0771
According to the coding, an ultra-basic IBIZA, right?
What are you planning to do with that powerful BCM?

[kevinp]

Yes! That was the first thing that came to my mind.

The first time I tried to match them and got this error, I went to a store and tried to buy Panasonic. Sadly, they didn't have them, and I ended up buying some unknown brand.

I have just ordered 4 CR2032 Panasonic batteries through Amazon.

--

About my upgraded BCM/GW, I'm not 100% sure if the upgrade was done correctly in terms of coding. Everything is working as expected, but those 2 terminal errors are causing a warning light on my instrument cluster (I am planning to fix it before the inspection, although I don't think it matters as long as everything works properly)

I have an autoscan from before the swap and pictures of every byte description, so I went through the BCM activating features and trying to determine what settings were previously enabled.
I wasn't sure about copying the long coding from one module to the other (my previous one was an 86 BCM). I have a peculiar issue with the Gateway, when I go to select modules, I see "0B-Sec. Air Heating", but in my gateway list, it jumps from 09 to 0D (I suspect it might be my VCDS software - I'll purchase an official version soon).
I didn't make any specific change on my GW coding, I thought BCM coding + GW installation list was enough

As a note, I was experiencing the exact same remote problem with my previous BCM.

It's an Ibiza 6J Reference Facelift 1.2 TDI from 2013 (75hp to 100hp ). I'm missing several features that I'd like to add, not because I need them, but because I enjoy working with computers, electronics, and wiring:

- Bi-xenon headlights (I already have them, just need to source AFS, Autolight switch, RLS, and headlight washers)
- Cruise control (I needed to upgrade from my basic BCM, so I went with the best one I could find)
- Front fog lights
- Electric mirrors (heated and auto-foldable)

I would also love to add:
- Lane change assist
- OPS (I have some €10 sensors from AliExpress)
- Leon MK3 steering wheel with buttons (I already have a working Toledo cluster, but haven't adapted the plastic yet)
- High Beam assist (I haven't researched thoroughly, but the front camera seems too expensive at around €400)

I'm not sure what else I'm missing (feel free to make my list longer ), but I'd love to implement as many upgrades as possible - not because I need them, but because I enjoy the satisfaction of doing it myself

Regarding the 771 module version, I noticed in your thread that you have the 772 (If I'm not mistaken). Should I consider upgrading the SW?, or it isn't worth taking the risk of potentially bricking my module (it was difficult to source - I ended up getting one from Poland)

[ciclo]

You must also transfer the previous GW coding. It's mandatory!

'BCM Max' 7H0 or 7E0 require the lights to be wired in a specific way, so detected Terminal 30 faults in this point are normal... until everything is wired properly along with a new BCM coding.

There's no problem updating the BCM 7E0 firmware from 771 to 772, as long as you have the flash file and a working VAS or VCP.
I mentioned it only because I found it interesting.

I think you'll really enjoy doing the modifications you already have in mind. "All of them are possible".
Thanks for commenting on your future project!

---
Warming your back and ass-legs is a comforting sensation, so I would add heated seats.

[kevinp]

Oh ok! I will transfer the GW coding tomorrow

I know that my lights are going directly to the headlights and I have to re-route them to the BCM IN and then BCM out to the headlight.

I will keep 771 as far as it works / there isn't any major change, just to be safe, I have never upgraded any module, and I'm not sure if I should trust my VAS interface (VCX SE) enough

Heated seats (as well as changing the seats ) seems interesting, will add it to my list!

BTW, is there any recommended dealer to get the original VCDS shipped to Spain? (it's ok if you want to PM rather than doing "spam" on public), I have seen them around 300€, not sure if there's anything near to 200$ as the original pricing.

Thank you so much for your time

[ciclo]

Some time ago, I bought my VCDS HEX-V2 directly from the Ross-tech website, "without intermediaries". English version. Shipping costs are what they are.
By the way, they should evolve directly to wireless devices from the basic version without the "damned" cable.
There are already many wireless devices that connect to the OBD2 port that their SW is starting to reach a high level..."without added costs".

I recommend you "the current" VAS 6154A with ODIS S and E sold on Ali. Once installed correctly (easy), the operating level is exactly the same as factory. Learning to handle it is quite simple (easy).

[kevinp]

Thanks for the info!

I'm buying VCDS from a Spanish authorized reseller. It's 300€ with "free shipping" versus 200$ + 125$ shipping + customs...

It seems weird to still have to use a cable to connect to OBD nowadays. I have a Launch tablet which I use for general multibrand diagnostics, and it's quite comfortable to be working in the engine bay with wireless OBD.

I will wait for AliExpress deals to get that VAS 6154A. It seems really interesting, although the interface seems harder to use than VCDS. I have enough time to learn

And now the big thing! Yesterday I was waiting to get my XHORSE remotes... but... you know... it was a black day. Today I got the 2 remotes I ordered, just swapped the transponder, key and battery (not Panasonic yet), generated SEAT remote (although now the BCM is from a T6 I think ), and they work! I have 3 working remotes now I've noticed that my non-working remotes have about 6 points of connection - it might be possible to get them reprogrammed....

About the GW, I have just transferred the coding, although I haven't notice anything, it does make sense to have the correct one , btw, could I ask how did you notice that I forgot to do it?

[ciclo]

Just intuition, coding the GW in the BCM PQ25 swap is often overlooked.
I'm glad you solved the remote issue, Xhorse remotes are pretty good.

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