Quick xenon upgrade question

[piehole1983]

Hi guys,

I've bought some xenon lights to fit to my halogen equipped car. I did a quick scan with VCDS before I start to check whether I have the option to enable them. From what I can see, I don't! (No byte 21). My module is 8P0 907 279 B. I've already read that I need revision F??

I can get the Central Electrics module from the same car the lights came from but my question is, does the engine type make any difference? The donor car is a diesel and mine is 1.6 petrol. Are there any security issues like we would have when changing the cluster for example?

 

[KurtisBye]

Yes the new CEM needs coding to match your existing and if you have bi-xenons also need loom adapters.

 

[piehole1983]

Thanks for the reply. I've been looking around and can see it's not such a big job to do. I'll carefully note the coding in my existing module and set the replacement module exactly the same before enabling anything to do with xenon. They're not bi-xenon should should plug straight in!

 

[Nessy]

Thanks for the reply. I've been looking around and can see it's not such a big job to do. I'll carefully note the coding in my existing module and set the replacement module exactly the same before enabling anything to do with xenon. They're not bi-xenon should should plug straight in!

Single xenon headlights do indeed plug straight in to the existing plugs for the halogen headlights.
The headlight-levelling motors though are different (they're wired to different pins too) on halogen and xenon headlights so unless you've modified them you're not going to have any headlight levelling.
I'm not referring to auto-levelling here, but to the 3 positions available to compensate for loads within the car that are controlled by the thumb-wheel to the left of the headlight switch.

 

[piehole1983]

Ah right, so the motors would maybe need swapped over from the halogen units as well as moving the pins in the plug?

 

[maxpayne]

Are you saying that it's possible to fit Xenon lights without an external ballast? Something like this? https://www.ebay.co.uk/itm/172240934155
Would be great if it was just a bulb replacement!


Sent from my iPhone using Tapatalk

 

[piehole1983]

Are you saying that it's possible to fit Xenon lights without an external ballast? Something like this? https://www.ebay.co.uk/itm/172240934155
Would be great if it was just a bulb replacement!


Sent from my iPhone using Tapatalk

No that's not possible without ballasts etc. Plus I've read that cheap kits destroy the wiper motor! I'm retrofitting genuine Audi xenon headlamps with integral ballasts.

 

[maxpayne]

Ah I see. There are kits on eBay that claim to be wiper motor safe, e.g. https://www.ebay.co.uk/itm/281743004211


Sent from my iPhone using Tapatalk

 

[piehole1983]

They'd maybe be ok if the car was programmed for xenon lights. The problem is manufacturers use pulse width modulation to "extend" bulb life on halogen lamps and also to increase brightness. Xenon ballasts need a steady uninterrupted power supply to operate properly.

 

[Nessy]

Ah right, so the motors would maybe need swapped over from the halogen units as well as moving the pins in the plug?

Exactly.
The xenon headlight motors have 4 wires going to them , the halogen motors have 3 , so you have 2 options really.
First is to try and work out the wiring and use the xenon headlamps as they are and modify the wiring to the adjustment motor (this was beyond me!).
Second option is to fit the halogen adjustment motors to fit the xenon headlights.
The xenon adjustment motors are also a different design, so you can't just swap the motors from the halogen headlights into the xenon's without modification.
The halogen motors will fit if they are turned through 90 degrees and you have access to a Dremel-type tool to make the necessary adjustments.
Have a search on this site for more info, that's where I got my information from, I did this job during the summer and posted up some info as well.
It's not a difficult job, just a bit fiddly.

Here are my postings on the topic;
http://www.audi-sport.net/xf/thread...-wiring-adaptor-required.277832/#post-2757430

Ah I see. There are kits on eBay that claim to be wiper motor safe, e.g. https://www.ebay.co.uk/itm/281743004211


Sent from my iPhone using Tapatalk

I think it's generally accepted that ANY type of aftermarket HID kit on an A3 WILL fry the wiper motor eventually (despite assurances by sellers to the contrary) and that the only safe option is to fit a set of Genuine Audi A3 xenon headlamps.
Besides, A3 halogen headlights are reflector units so fitting aftermarket HIDs will dazzle other road users, Genuine A3 xenon's are projector units so it isn't an issue.

 

[piehole1983]

Your thread is great, thanks for that.

I got the hold of the technical data for the xenon levelling motor and the control strategy is totally different (2 phase DC) to the halogen unit so unless I install the complete auto levelling system the motors will have to be changed. I'll take the motors from my halogen units like you did.

I also need to change my CEM so once I do that I'll fit the xenon lamps.

 

[piehole1983]

Anyone know if CEM revision D has byte 21 available? I can get one cheap.

 

[Nessy]

Your thread is great, thanks for that.

I got the hold of the technical data for the xenon levelling motor and the control strategy is totally different (2 phase DC) to the halogen unit so unless I install the complete auto levelling system the motors will have to be changed. I'll take the motors from my halogen units like you did.

I also need to change my CEM so once I do that I'll fit the xenon lamps.

No worries, glad to be able to help.

 

[nothingness]

Exactly.
The xenon headlight motors have 4 wires going to them , the halogen motors have 3 , so you have 2 options really.
First is to try and work out the wiring and use the xenon headlamps as they are and modify the wiring to the adjustment motor (this was beyond me!).
Second option is to fit the halogen adjustment motors to fit the xenon headlights.
The xenon adjustment motors are also a different design, so you can't just swap the motors from the halogen headlights into the xenon's without modification.
The halogen motors will fit if they are turned through 90 degrees and you have access to a Dremel-type tool to make the necessary adjustments.
Have a search on this site for more info, that's where I got my information from, I did this job during the summer and posted up some info as well.
It's not a difficult job, just a bit fiddly.

Here are my postings on the topic;
http://www.audi-sport.net/xf/thread...-wiring-adaptor-required.277832/#post-2757430



I think it's generally accepted that ANY type of aftermarket HID kit on an A3 WILL fry the wiper motor eventually (despite assurances by sellers to the contrary) and that the only safe option is to fit a set of Genuine Audi A3 xenon headlamps.
Besides, A3 halogen headlights are reflector units so fitting aftermarket HIDs will dazzle other road users, Genuine A3 xenon's are projector units so it isn't an issue.

You can put HID kits into audi xenon assemblies, like mine