I've converted the speedometer from mini DOT display to maxi DOT display three times. I never had to code the BCM. Speedometer installed, immobilizer adapted with both keys, speedometer coded, done. An active immobilizer doesn't interfere with any other functions.

My dad has just been round, disconnected the battery to reset everything, the windows started working and they're now all closed 👌 car still wouldn't start though. I have a feeling there's a communications fault between the ECU and the cluster... i'm going to get it booked in with a VAG specialist and see if he can sort it. For now I will change the head unit back to the standard head unit and see if that makes any difference for the communications 👌

The radio is completely irrelevant. It is not a component of the immobilizer system.

42 minutes ago, Cairus said:

The radio is completely irrelevant. It is not a component of the immobilizer system.

Yeah, but could it not block communications between the diagnostic computer and the ECU?

The mechanic that looked at it today has spoke to the auto electrician next to his garage today and he thinks it could be the canbus block that's playing up... its starting to get well above my head now!

After market radios can interfere with canbus system somehow. Cairus is right in that it has nothing to do with imobilser but it can stop readers connecting to ECU in some cases. I would just disconnect radio completely and try to access ecu again. Might need VCDS to read it.

Alasdair

On 29/01/2026 at 09:37, Alasdair1 said:

After market radios can interfere with canbus system somehow. Cairus is right in that it has nothing to do with imobilser but it can stop readers connecting to ECU in some cases. I would just disconnect radio completely and try to access ecu again. Might need VCDS to read it.

Alasdair

So another small update... my pal with VCDS finally came over today... we tried plugging the car in with the aftermarket head unit in and it didnt want to connect at all... disconnected the head unit, then VCDS tried to connect to the car... then it failed to connect... i've attached a photo of the message VCDS said.

My other pal is going to come round tomorrow and have a deep dive on the car, he thinks it could be a faulty BCM.

We still dont understand why we can't connect to the car though!

Edited 6 February6 Feb by Robdog10000

Don't get me wrong, does your colleague know what he's doing?

Yes... multiple people have now looked at the car...

2x auto electrician's

1 self employed mechanic (specialist in JDM cars, rather than VAG)

And 1 pal who is quite handy with VAG's

All original data pointed towards cluster failure... replaced cluster and no different.

Next is to check BCM tomorrow morning

Tried keeping costs down to a minimum so far, so haven't booked it into a proper garage yet

So we've now removed the BCM and also the gateway module to check them for water ingress etc...

The BCM looks brand new inside, absolute zero damage to the circuit board...

Just had a look inside the gateway module and with my untrained eyes, i'm unsure if this looks correct or not (photo uploaded)

It looks like there's some sort of residue on the silver part of the circuit board... 🤔

With VCDS not connecting to the car and the only message it is displaying is "function not supported by the gateway" we're fully expecting the gateway to be causing all the issues i've been experiencing (Google Gemini is pointing in that direction too, erratic lights on dash, central locking malfunctioning etc...)

So i've just sourced another gateway module on ebay... brand new is £477 🤯🤯

And i'll get it cloned then see what happens then!

You To Always Autoscan

What say vcds when you Connect directly

3 minutes ago, Cairus said:

You To Always Autoscan

What say vcds when you Connect directly

Both when you use auto scan and also select car from drop down box, it says function not supported by gateway...

I've had vcds connected multiple times in the past without an issue

Why drop down? Vcds original?

7 minutes ago, Cairus said:

Why drop down? Vcds original?

The drop down box on the left...

Edited 11 February11 Feb by Robdog10000

So, huge update here... ITS FIXED!

I recieved the gateway module back this afternoon and put everything back as it should... started the car and everything seems to be working fine again! So it was definitely the gateway module that was knackered.

The only lights on the dashboard now are the airbag light and the bulb warning light (i was expecting the bulb warning light as the levelling sensors are knackered)

So all seems good now! Just need to try and reset the airbag light and sort the levelling sensors for the headlights, then get her booked in for MOT!

HAPPY ROB 😁

Glad you got it fixed and hopefully airbag light will stay off once reset.

Alasdair

1 hour ago, Alasdair1 said:

Glad you got it fixed and hopefully airbag light will stay off once reset.

Alasdair

Thanks buddy! Fingers crossed for the airbag light 🤞 is dont see any reason for the light being on, apart from staying on due to the fault with the gateway module... so once reset, hopefully it will stay off 🤞