Hello everyone,

 

I have a Skoda Yeti from 2012 and I have a problem with the right side rear lights (the two 5 watt glass bulbs). The rear light in the right side is not working. First I thought that it was both bulbs which was blown and I changed them. This did not help. Now I have measured directly in the rear light connector and there is no power there too - so the problem is not in the light itself. All other lights on the car are working. It is also not the fuse (no. 16 in the motor fuse compartment) because the front light in the right side is working and they are connected to the same fuse. 

 

Does anybody know how the rear light is switched on and off - I am assuming that there must be a relay or a lights controlbox somewhere, but I dont know where to look. I would like to measure if there is power comming from the relay/controlbox. That way I can identify if the cable between the connector in the light and the relay is OK.

 

Any help highly appreciated

Regards

Thomas V.

What lights are not working?
Brake light, indicator, rear fog or sidelight.

It is the normal rear light. Everything else works as it should.

Regards

Thomas V.

Have you checked whether there is voltage at the plug that goes into the unit?

You haven't had towing electrics fitted recently?

It is the normal rear light. Everything else works as it should.

Regards

Thomas V.

So none of the bulbs in the right rear light work?

Hello everyone,

 

I have a Skoda Yeti from 2012 and I have a problem with the right side rear lights (the two 5 watt glass bulbs). The rear light in the right side is not working. First I thought that it was both bulbs which was blown and I changed them. This did not help. Now I have measured directly in the rear light connector and there is no power there too - so the problem is not in the light itself. All other lights on the car are working. It is also not the fuse (no. 16 in the motor fuse compartment) because the front light in the right side is working and they are connected to the same fuse. 

 

Does anybody know how the rear light is switched on and off - I am assuming that there must be a relay or a lights controlbox somewhere, but I dont know where to look. I would like to measure if there is power comming from the relay/controlbox. That way I can identify if the cable between the connector in the light and the relay is OK.

 

Any help highly appreciated

Regards

Thomas V.

 

 

So none of the bulbs in the right rear light work?

 

Cough! Should have gone to SpecSavers!   

That's a lot of help, he said "All other lights on the car are working"

 

I took that to mean both front and left rear.

Edited 18 April, 201610 yr by Urrell

Cough! Should have gone to SpecSavers!   

I think Urrell is asking if either of the rear RHS bulbs work (there are two on each side....)

 

Jim

 

 

EDIT perhaps he didn't! ......

Edited 18 April, 201610 yr by muddyjim

Both of the two small 5 Watt bulbs does not work on the rear right side. Everything else works on the entire car. No I have not had any towing equipment fitted lately. I have measured directly in the plug and there is no power between chassis and the violet/red cable.

 

Does anybody know which relay controls the right rear lights? Where is it placed?

 

Regards

Thomas V.

Thanks.

There is no relay as such, since the car uses the CanBus system.

I wonder if there is a plug in the loom somewhere in the back of the car that has become detached, perhaps behind the trim panel?

I suspect you are going to have to get the car interrogated to see if there are any fault codes held. 

Just one silly question- are the indicators in the neutral position?.

Just one silly question- are the indicators in the neutral position?.

It doesn't work regardles of the position.

 

 

There is no relay as such, since the car uses the CanBus system.

There must be some sort of a relay or control unit. The CanBus can not switch high currents by itself.

 

Regards

Thomas V.

It doesn't work regardles of the position.

 

 

There must be some sort of a relay or control unit. The CanBus can not switch high currents by itself.

 

Regards

Thomas V.

I doubt there is much current draw with lights these days.

I doubt there is much current draw with lights these days.

Well, each of the front bulbs draws 55 Watts or 4.5 amps. That is way above the currents that is flowing through the CanBus system (as fas as I know)

Regards

Thomas V.

Does 'switching' involve significant current?.

The CanBus is able to switch high currents, and 2 x 5 watt rear lights are not high current. 

There is a Lighting Control Unit somewhere as one member burnt one out after having dodgy towing electrics fitted, bit it was all solid-state.

Edited 19 April, 201610 yr by Llanigraham

Are you getting a CHECK BULB warning on the maxidot display and a yellow warning light in the LH instrument? If not, it suggests either a programming fault on canbus, or the translator unit being faulty because it's still telling the main computer that the lights are working ok.

 

The Canbus controller/translater for the right rear side lights is in the inner wing, behind the RHS boot trim. To get at it, you have to remove the boot floor entirely, plus the underfloor boxes if you have a spare wheel, followed by the plastic slam panel that runs across the car by the boot catch (and that's a sod to put it back in place!). Then remove the hook rail (3 long bolts), the C & D post panels and then remove the side trim panel in the boot. The unit is a small black box held in place with a couple of small torx screws and has 2 loom connector plugs that simply unplug. There are no user serviceable parts in the translator, it's a throw away & replace job if it's faulty I'm afraid

 

But, before you go to all that trouble, it would be worth finding either someone with VCDS, or a friendly dealer who can run a diagnostic scan on the car to see if it reveals what the problem is and to see if it can simply be reprogrammed to put it right.

Much like other PQ35 based cars, all the lighting is controlled by the BCM which is an electronic control module located above the pedals in the drivers footwell. If you have knee airbags this will make access harder. Unfortunately, this generation of BCM has shown itself as very sensitive to unexpected loads such as aftermarket HID kits or even badly designed LED drivers. Both of these can cause damage to the internal components normally resulting in a replace module being fitted.

 

As for CAN bus, that's almost certainly nothing to do with this problem. It's just a communication protocol between different electronic modules. The current switching for the lighting is all done by fets in the BCM, I don't think there are any relays involved iirc. Even the 'tick-tock' sound for the indicators isn't a relay, it's produced by a speaker in the instrument cluster!

 

You need to get a scan done via VCDS as it will show up any fuse, wiring or bulb issues. It's unlikely to be configuration as that would effect both left and right tail light bulbs.

 

Both left and right tail lights should be connected directly to BCM and I think it's connector A, pin 27 and connector C, pin 3 on the WD I have