Octavia mk 2 2011 - had a garage wire the rear fog lights so both go on, but now have lighting error light active on dash. Can anyone please help?

Before saying more - I have read everything I can find here and elsewhere on this subject and have found nothing that clearly helps me fix the issue. The car has a dual filament fog light - both left and right side have bulbs in place and appear to be configured the same, aside from the fog light, which from the factory, is set to light on the right side only.

I thought Skoda might help, but they were hopeless - they replied to tell me that both rear fog lights are set to activate simultaneously, which is just nonsense, so no help there.

I then handed the problem over to a garage here in Germany, Euromaster, and they wired the rear fog lights across right to left and left to right, thinking this would simply swap the lighting. What actually happened - both fog lights now go on, but an error message advises I check both, then, once that passes, I get the lighting error light on the dash. I expected this, because it has been noted on this forum when this issue has come up in the past.

As far as I can see, there is no clear description of how to get around this for the post FL MK2, but I really hope someone can offer me advice/help with this.

After failing the TUV (German MOT) for this, I have a follow up to check the conditionals have been corrected. They are likely to fail me on the error lamp, despite the fact that everything works as it should - did anyone ever get around this problem?

Many thanks for any help you might have.

You could try a smart bypass relay for towing and wire the fog lights to it. I first fitted a towbar to a Seat but when trailer was connected the blown bulb symbol illuminated. I then fitted a smart bypass relay system and all was good. Only thing I had to do was run a live from +ve battery terminal with an in line fuse. On my octavia it was already in place on right hand side in boot.

Your lighting error will be because the fog light circuit is now sensing a higher current than expected (because of the extra lamp wired-in) Was the change entered into the can bus?

Edited 15 November, 202515 Nov by Warrior193
correction

10 minutes ago, Alasdair1 said:

You could try a smart bypass relay for towing and wire the fog lights to it. I first fitted a towbar to a Seat but when trailer was connected the blown bulb symbol illuminated. I then fitted a smart bypass relay system and all was good. Only thing I had to do was run a live from +ve battery terminal with an in line fuse. On my octavia it was already in place on right hand side in boot.

Many thanks... I'll do a bit of reading and see if I can try that out.

I have very basic understanding of the electronics, aside from changing things in and out.

Cheers! 👍

10 minutes ago, Warrior193 said:

Your lighting error will be because the fog light circuit is now sensing a higher current than expected (because of the extra lamp wired-in) Was the change entered into the can bus?

Many thanks!

The guy in the garage said they couldn't resolve the issue using, the same system as VW use - more than that I can't say - they were pretty sheepish when the problem I explained would likely pop up did, after they assured me it was an easy fix... I doubt they went as far as entering any changes into the car's system... I'll give them a call on Monday to see if they did, and/or see if they can enter the change if they did not already try.

Cheers! 👍

I went for the smart bypass relay as my local skoda garage wanted about £100 to tell the car I had a towbar fitted probably as I did it myself. Its fairly simple to connect. I just followed instructions. As said had to run a cable from battery at front of car with inline 15amp fuse. Managed to feed it through the grommet in bulkhead beneath glove box and then tuck under carpets to rear. Used one like this Not sure if you could use the rear cigarette socket in boot (mines an estate) for a live feed?

Edited 15 November, 202515 Nov by Alasdair1

My 2014 LHD (in Germany) Rapid has a single foglight on the rear only on the driver's side

What about extending the wiring from the your driver's side to the passenger side or must it have two foglights?

Edited 15 November, 202515 Nov by Lee01

Actually after thinking, you would probably have to do it for both sides to avoid the bulb out error.

32 minutes ago, Lee01 said:

My 2014 LHD (in Germany) Rapid has a single foglight on the rear only on the driver's side

What about extending the wiring from the your driver's side to the passenger side or must it have two foglights?

Many thanks!

I had hoped to only have one on the rear left - the garage did just that, extended a wire from the driver side (right in this case) to the left rear fog light, and then one from left to right - the idea was to swap them over, giving me only one rear fog light on the left... What happened was both now light - the garage is not sure why and the error message comes up.

I think I will have to double check what the garage did - maybe they only jumped the right side to the left.

Thanks!

Just read your follow up - yes, I am thinking they maybe only jumped a wire from the right to left and this could be the problem! Cheers! 👍

@Crai I don't know for the Octavia you have but I believe Carista can disable the bulb check for my Rapid.
It may be possible to use that or similar or VCDS to code out the fog light bulb check on your Octavia?

14 minutes ago, Lee01 said:

@Crai I don't know for the Octavia you have but I believe Carista can disable the bulb check for my Rapid.
It may be possible to use that or similar or VCDS to code out the fog light bulb check on your Octavia?

I'll check that out - my father in law has a diagnostic kit. I'll see if it can switch this off for the TUV, then look for a more permanent solution.

Many thanks!

2 hours ago, Alasdair1 said:

I went for the smart bypass relay as my local skoda garage wanted about £100 to tell the car I had a towbar fitted probably as I did it myself. Its fairly simple to connect. I just followed instructions. As said had to run a cable from battery at front of car with inline 15amp fuse. Managed to feed it through the grommet in bulkhead beneath glove box and then tuck under carpets to rear. Used one like this Not sure if you could use the rear cigarette socket in boot (mines an estate) for a live feed?

Cool! Thanks! I've managed to find a video where someone shows how they fitted one for a towbar, and think I understand how to use it as a relay between the left/right crossover wiring.
As for power - I reckon I'd have to run it from the battery because there's no lighter socket in my Octavia.
Very many thanks, if I can work out how to fit the bypass relay, it should 'mask' what's going on and sort things out... 🤞

As said I ran it through the main rubber grommet in bulk head behind/below glove box . Think I pushed a piece of rigid wire through first and then taped cable to it and pulled back then ran under carpets into rear.

Alasdair

17 hours ago, Crai said:

I'll check that out - my father in law has a diagnostic kit. I'll see if it can switch this off for the TUV, then look for a more permanent solution.

Many thanks!

There is probably an option in the BCM to allow twin rear fog lights, as I believe that this is a standard requirement in some countries. If present, enabling this would allow both lamps to operate without flagging an error.

I've always thought fitting a single rear fog light rather poor - apart from cost, the only positive factor I can see is minimising unnecessary rearward glare when lights are misused - which misuse should be policed a lot more.

Edited 16 November, 202516 Nov by Warrior193
typo

1 hour ago, Warrior193 said:

There is probably an option in the BCM to allow twin rear fog lights, as I believe that this is a standard requirement in some countries. If present, enabling this would allow both lamps to operate without flagging an error.

I've always thought fitting a single rear fog light rather poor - apart from cost, the only positive factor I can see is minimising unnecessary rearward glare when lights are misused - which misuse should be policed a lot more.

There is... We had it enabled on our old MK2.

The original poster simply needs to remove the new wiring that has been added and get the car coded properly by someone that knows what they are doing

1 hour ago, Warrior193 said:

There is probably an option in the BCM to allow twin rear fog lights, as I believe that this is a standard requirement in some countries. If present, enabling this would allow both lamps to operate without flagging an error.

I've always thought fitting a single rear fog light rather poor - apart from cost, the only positive factor I can see is minimising unnecessary rearward glare when lights are misused - which misuse should be policed a lot more.

I'm calling the Skoda dealership tomorrow to see if this is an option - from old posts on this, it seemed there was a problem doing this, and from my comms with Skoda, very unhelpful and wrong concerning how the car was originally issued in the UK... The garage I took it to - Euromaster told me they could not do this using a VW/Skoda computer. Still, I suspect you must be right - there are twin filament bulbs in each lamp, so there must be a way to activate them.

Many thanks 👍

19 minutes ago, skomaz said:

There is... We had it enabled on our old MK2.

The original poster simply needs to remove the new wiring that has been added and get the car coded properly by someone that knows what they are doing

Good to hear a voice that had this option enabled on a MK2! You're right, I'm pretty sure the garage did not really know what they were doing, or lacked the tools to do it properly!

I'll pop over to a local Skoda dealer tomorrow morning...

Many thanks! 👍

Does this video help?

1 hour ago, Liger1956 said:

Does this video help?

Thanks! I am hopeful Skoda will be able to get into things with software like this - its a bit above my head to be honest, but suspect this is the kind of solution needed, and the one I should have opted for before letting Euromaster argue that it could not be remapped, but had to be hard wired!

Cheers! 👍