[graaja]

Installed OEM Valeos BiXenons in my Polo GT TSi and also upgraded the stock BCM to BCM Max that supports original BiXenon operation and also various other features.

This is by far, the toughest DIY I have done on the GT. The intent of this thread is to provide all the information necessary for a OEM BiXenon upgrade, and also to share the mistakes I made and the learnings I got from these mistakes which can be useful to others who plan this upgrade. Owing to the complexity and the amount of work involved in the DIY, it is not possible for me to provide a step by step procedure for everything. Instead what I have tried to do is provide all high level information like components required, major tasks needed to complete the install, VCDS coding, results and some learnings. I have also provided links to various threads I referred during the installation. If any information is missing, feel free to ask and I will do my best to provide this information.

Credits:

I would like to thank the following people without whom this installation would not have been possible:

• “ciclo”, a DIY enthusiast and an extremely knowledgeable expert on Polo platform from uk-polos forum for the wiring harness and the guidance he provided throughout the installation
• “firegrafik”, also from uk-polos forum who helped me source BCM Max from Russia. Without BCM Max, this project would have become a non starter.
• Our own Gannu for all his DIY threads and patiently answering all my questions. I got plenty of information from his threads that helped me during this install. He even sourced a couple of packs of BondTite from Gujarat to help me install the RLS and IRVM (that is a long story for later)
• TBHPian “TheSaint” (who has the OEM BiXenons in his GT) for providing me with part number and source for the BiXenons and patiently answering my questions on his experience with these BiXenons.
• A big thanks to my wife who put up with all the mess I created during the installation. At one point of time, our living room looked like a warehouse with lots of cartons, components and cables lying around.’
• Biggest thanks to my friend Pandiyan who worked with me for 3 days to complete the installation (he did more than 50% of the wiring). Without him, this installation would not have been possible.

References:

Gannu’s BCM upgrade thread
Gannus’s instrument cluster upgrade thread
Gannu's IRVM installation thread
Various threads on BiXenon upgrade in UK Polos forum

Decision to Upgrade:

It would be difficult to believe, the decision to upgrade to OE BiXenons was in part triggered when I heard the pricing of the Polo GTi. There was a small wish inside me to upgrade to Polo GTi if the initial rumors of the price of 20 Lakhs were to be believed. Then they dropped the bomb with a pricing of 35 Lakhs.

As this was way too expensive and out of my reach, I decided to spruce up the GT and make it GT 2.0 and keep it for a very long time. The upgrade to KW Street Comfort coilovers was the first move in this decision.

I had already upgraded the original halogen headlights to projectors (documented here). However, I had many issues with this installation

• The H1 bulbs failed and had to be replaced
• The projectors failed and had to be replaced
• Had to change to 35W Hylux ballasts because of the unreliable 55W ballast provided by the installer
• The replaced projectors had too much of foreground light which reduced the distance vision on high beam
• Too much clutter of wires in the engine bay

With all the above issues with the retrofit, and my decision to spruce up the GT, I decided to upgrade the headlights to OEM BiXenons.

Initial Research and decision between LED headlights vs. BiXenons, BCM upgrade etc.

Once I decided to upgrade to OEM BiXenons, I spent lot of time in various forums reading about OEM BiXenons. That is when I came across various threads in uk-polos.net a forum dedicated for Polo owners in Europe. I saw many discussions on upgrading OE halogen headlights to BiXenons or LED headlights.

All of these discussions pointed out to the requirement to upgrade the BCM to BCM Max to get the most out of the BiXenons. It is possible to just upgrade the headlights using a 10 pin to 14 pin adapter wiring which would be the easiest, but this will not support full DRL and cornering lights. Also, many Polo owners had also upgraded to the LED headlights found in the Polo GTi and the now special edition in Vento.

So, I had the following decisions to make:

LED headlights or BiXenons:

Though LED headlights have that Wow factor, I found that the LED headlights for the Polo GTi were very basic with reflector based design and with only leveling control. I also read that LEDs may not be that effective in rain. On the other hand, the BiXenons have excellent lighting pattern and coverage, and have the static cornering lights which are very useful while driving through winding roads. Also, I love the DRL design that is similar to Passat and Jetta. So, this decision was simple – I decided to go with BiXenons.

Simple headlight upgrade or full blown upgrade with BCM Max:

The BCM that comes in Indian Polo is 6R0 937 087. This does not natively support BiXenons or LED headlights. In fact in our Indian Polo the BCM does not control the headlights at all. The high beam, low beam and the parking lights are controlled directly by the headlight switch. On the other hand a BiXenon requires direct control from the BCM to control various special features like powering the low beam during flashing, controlling brightness of DRLs, controlling the cornering lamp etc., which the 087 BCM does not support.

The advantage of doing a simple install with the 10 pin to 14 pin adapter harness was that I could finish the install in a couple of hours. However, following are the disadvantages with this approach:

• The DRLs will have to be wired to the parking light signal in the original wiring. They will have to be manually turned on by selecting the parking lights position in the headlights switch. Also special functions like DRLs dimming on parking light function, DRL always on even when light switch is off, DRL turning off when turn signal is activated etc will not be possible.
• The cornering light will not have any function. I have seen some installations where the cornering lights are wired to high beam. But this totally beats the purpose of cornering lamps.
• Automatic headlight function is not possible the OEM way. It is still possible using the retrofit auto headlight switch available in AliExpress (I had this installed earlier)
• Flashing using the indicator stalk will not work. In a BiXenon, the high beam only activates the shield that lifts and exposes the full light beam. For the light to turn on, the ballasts have to be powered as well which is controlled by the low beam signal. However, in the original lighting installation, low beam is not powered during flashing. Because of this the BiXenons will not light up while flashing if the headlights are off.

The advantage of doing a full upgrade to BCM Max is that all the functions from the OE BiXenons can be implemented. But the biggest disadvantage is that this will require a total wiring change and out goes warranty. Till this point, all the upgrades I did were plug and play with no wires being cut. In case of warranty requirement, I could put back the original components in no time. But a BCM upgrade would be a point of no return. But then:

I decided to take the risk and go for the full blown upgrade with BCM Max, with Automatic Headlights and Rain Sensing Wipers.

I fervently hope that I don’t have to go for any warranty support to VW. The only warranty that I am interested is in the DSG and hope VW would support me on that.

Index:

Procuring Components
Headlight Install and RLS/IRVM Install
Wiring concept explained
Wiring DIY
VCDS Coding
Results, Important Learnings, Pending Issues and Future Plan

I will add new links to the index on key future updates to the installation

[graaja]

Procuring Components:

Once I decided to go with BiXenons and BCM upgrade in the last week of November, the painful process of collecting all the components started. Putting together all the components took close to 10 weeks. There were some unnecessary delays due to bad planning from my side as well.

BiXenon headlights – 6R2 941 039D and 6R2 941 040D

TheSaint helped me with the part numbers for the BiXenons and he also gave me the link to an online store where I could get this. The cost was 1200 Euros including shipping.

Link to CarSystems store

However, this was out of stock in their website for close to three weeks. I then searched other websites and found another website www.allcarpartsfast.co.uk with the headlights in stock. The price listed for the headlights was 300 British Pounds each. Links to the store for both the headlights below:

6R2 941 039D
6R2 941 040D

Including shipping, it cost 760 pounds for both the headlights. As the value of the pound was down due to Brexit, this worked out to 64K INR. I thought this was a good deal compared to the carsystems.pl price and placed the order. The lights arrived in a week and I had to pay a customs duty of about 18K.



When I opened up the lights, I was in for a rude shock. These were just the headlight housings. They did not have the ballasts, HIDs, H7 lamps for cornering and indicator lamps. I used the H7 lamps from the original headlights. I had to order all other parts separately from the following links.

Ballasts from carsystems.pl
Philips Extreme Vision 4800K D3S HID bulbs from powerbulbs
Indicator lamps from AliExpress

In the end, I paid about 10K more than what I would have paid for the full set from carsystems.pl.

BCM Max - 7E0 937 090

The next most important part required for the upgrade is the BCM Max. From the discussions I had with ciclo, for the Indian Polo I had to go for the 7E0 series (7E0 937 090B). But unfortunately, this was very rare and I could not find it in any online stores. Many stores had the 7H0 series of BCM, but ciclo made it clear that 7H0 will not work with Indian Polo. I found a couple of used 7E0 BCMs in eBay, but he said there is no guarantee that a used BCM that has been configured for a different car would work in the Polo.

I searched for this BCM for almost 3 weeks and was frustrated to the level that I even questioned my decision to go with such a complex upgrade. That is when another user from the UK Polos forum “Firegrafik” came to my rescue. He said that one of the local dealers in Russia has stock of 7E0 and he had procured this for his own upgrade. He was very kind to source this locally and ship it to me. The BCM arrived in 3 weeks from Russia.

Below is the picture of the BCM Max



Below picture is the comparison between the existing BCM and the new BCM. Note the several new pins present in the new BCM.



10 pin to 14 pin adapter wiring harness



The OE BiXenon headlight has a 14 pin connector, whereas our Polo has a 10 pin connector. This adapter connects the high beam, low beam and turn signals from the 10 pin connector to the 14 pin connector. It also has three wires for DRL, Parking and Cornering lamps that need to be connected to the BCM. I got this from eBay. This is also available in carsystems website. If ordered along with the full set of headlights this will save some shipping cost.

Link to 10 pin - 14 pin adapter

Rain light sensor, IRVM and auto light switch

I ordered the rain light sensor, IRVM, RLS wiring and Auto light switch from AliExpress. This arrived in 20 days.

AliExpress link to IRVM, RLS and Auto Light Switch



I made a big blunder in ordering this particular set. More about this later.

Wiring harness for the fog lamps



The Indian Polo has the fog lamps working as cornering lamps and are controlled by the BCM. In the new installation, the cornering lamp function will be shifted to the H7 bulbs in the BiXenon headlights and the fog lights will be disconnected from the BCM. A new wiring harness will be required to drive the fog lamps directly from the switch through a fuse circuit. I ordered this from eBay.

eBay Link to Fog Light Wiring Harness

Dimmer switch 6Q0941334



As the headlight leveling will be non-functional once the BiXenons are installed (this requires an AFS controller for auto leveling which is another project for the future), I decided to change the headlight leveling switch with the dimmer control switch. This can be used to adjust the brightness of the instrument cluster and the brightness of the lights on various buttons (steering mounted controls, window control switches etc). ciclo got this for me and shipped it along with the wiring harness.

Wiring harness for the BCM Max

This is the another very important piece to complete the installation. As I had mentioned earlier, ciclo from the UK forum makes these wiring harnesses as a hobby. As there are several variants in the electrical wiring of the Polo 6R platform, he asked me to provide him with many details like a VCDS Autoscan of the car, various pictures of the headlight connector, headlight leveling switch connector, relay carrier and the fuse box.

He also asked me to perform tests by removing various fuses in the fuse box and the effect that particular fuse had on the headlight function. Once I provided him with all the details, he prepared the wiring and sent it to me from Spain. It took 3 weeks for this to arrive.



Everything was neatly packed. There were totally four cable assemblies, various fuses, and a tool to remove pins from existing connectors. He also sent me a surprise gift of LED license plate lights that is supported by BCM Max. He also sent me a 11 page PDF document with meticulous instructions on where each wire has to be connected (more on these later). The package also had the adapter plate for the VW flip camera. He told me that he designed this adapter when he installed the reverse camera on his Polo, and this is being sold on various online stores now including carsystems.pl. I have made an AutoCAD drawing of this and have shared this in my VW flip camera thread.

Finally, after almost 10 weeks, all the components required for the installation:



Ross Tech VCDS Cable

I also got the original Ross-Tech VCDS cable. I had three versions of AliExpress cables earlier. All of them failed to identify the ABS/Brake controller in my GT. As this was a major upgrade, I did not want to be stuck at a stage where the VCDS cable did not recognize the new BCM. So, I played it safe and got the original cable. Ross-Tech also came up with a new enthusiast version which was limited to 3 VIN numbers and they priced it $200 compared to $350 earlier. Paid $80 for shipping and 2.5K as customs duty. Considering the results I got from this DIY, I feel this was a worthy investment.



Cost of components:

1. Headlights - 760 British Pounds
2. Ballasts - 245 Euros
3. D3S HID Bulbs - 160 British Pounds
4. Turn signal lamps - 17 USD
5. 10 pin to 14 pin adapter harness - 50 Euros
6. Fog light wiring harness - 40 Euros
7. BCM Max - 125 USD
8. BCM Max wiring - 160 Euros
9. IRVM, RLS and Auto switch - 150 USD
10. Dimmer switch - 40 Euros
11. Ross Tech Cable - 280 USD
12. Customs duties - 31K INR

[graaja]

As this was going to be a complex install, I decided to break it up into three parts

1. Install the headlights and make the High and Low beams work. Route the DRL, parking and cornering light wires into the driver side footwell
2. Install the rain light sensor and IRVM
3. BCM upgrade

Installation of Headlights:

This was the simplest task. All I had to do was remove the existing projector setup, install the new headlights, connect the headlights to the existing wiring using the 10 pin to 14 pin adapter and route the DRL, parking light and cornering lamp cables to the driver’s footwell.

A small digression. One great advantage with the OEM BiXenon headlights is the clean install. This is because the ballast, ignitor and the necessary cabling are included as part of the headlight assembly. The only connection required is the 14 pin connector.

The ballast fixed to the bottom of the headlights.


The D3S bulb has in built ignitor and fits inside the headlight assembly.


Existing headlights removed. All those cables were inside the engine bay.


The 10 pin to 14 pin adapter connected to the existing 10 pin connector. This is the only extra cable that goes in the engine bay.


New headlight fixed.


Compared to the clutter of wires in the engine bay with the previous retrofitted projectors, this installation is very clean.


I used this keyhole shaped rubber stopper to route the DRL, parking and cornering lamp wires into the driver side footwell.


Cut a small hole in this piece using a knife.


Route the wires through the plug and bunch and tie them inside the driver side foot well.


With this, I had the low beam, high beam and the turn signals working. The cornering lights and DRLs were not functional. Also, as I had explained earlier, when the headlight is off, flashing does not work.

Important Notes:

• To fix the new headlights an M6 x 25mm bolt with a large washer (I used a washer with 25mm outer dia) is requred. The existing screw is too short.
• The route I used to bring the wires through the firewall is only available in the GT TSi which is an automatic. In manual cars like GT TDi or other Polos, this is used for clutch cable and cylinder. In these cars, you will have to use a different route through the firewall.

Installation of RLS and IRVM

This part was a total disaster, and is not yet complete as I write this thread. I did not take many pictures during this step as well as I was more into disaster management

As I had mentioned in the previous post, I had procured the rain light sensor and IRVM meant for Jetta from AliExpress.

The first problem I faced was how to position the sensor and the mirror. In the OE installation, the sensor is integrated into the mirror base like the picture below which shows the sensor integrated into the mirror base of my Jetta.



This requires the windshield to be designed for the particular base and sensor. As you can see in the above picture, the black hatch pattern printed on the windshield has an opening for the rain light sensor. And the area where the base attaches with the windshield is painted with black primer.

In case of the Polo, the black hatch pattern does not have an opening for the sensor.


So, I will have to mount the base well below the pattern. But this will make the IRVM too low and will block visibility. The other solution is to fix the new mirror base around the existing mirror base and fix the sensor separately.

I chose to fix the sensor on the passenger side. As there were two bases in the set I got from AliExpress, I fixed one base around the existing mirror base and another base on the passenger side. However, I made some mistake in the application of the glue that when I tried to mount the new IRVM, the new base came off the windshield. I then fixed the OE manual dimming mirror to the existing base. And this is how the windshield looked - a total disaster!



The passenger side location of the rain light sensor is also not correct. The sensor should be located completely inside the area of the wipers. In my case, half of the sensor was outside the wiper’s range.

I am now getting the rain light sensor and IRVM that comes in the latest Polo. I plan to change the windshield as well with the latest one so that the rain sensor is integrated into the mirror base. I will update the thread once I complete this. Here is the list of components that I plan to get.

3G0 857 511E SMA - mirror
6C0 868 438 9B9 – mirror cover upper
6C0 858 548A 9B9 – mirror cover bottom
6C0 868 168A 9B9 – mirror cover
5K7 955 559C - rain-light sensor
8K0 971 833 connector
000 979 034 E repair wires 2 pieces

The complete set is also available in AliExpress in the following link.

AliExpress Link to RLS/IRVM for Polo

A funny story: It took me a couple of weeks to source BondTite which Gannu had recommended in his IRVM DIY thread. I could not get BondTite locally in Coimbatore. The order I placed in Amazon got canceled as the vendor did not ship in time. I placed another order with another vendor, but that too did not ship for a few days. Meanwhile, friend, colleague and fellow TBHPian srinivasnvns also searched in Bangalore and was trying to get me a couple of packs. I was also in contact with Gannu discussing the problems of the IRVM install and he was kind to have his friend from Gujarat ship a couple of packs to him. Then all of a sudden from nowhere, the package from Amazon arrived. There were 24 packets of BondTite. And srinivasnvns was successful in getting two packs, and Gannu had two packs. From no BondTite, I was now in a position to open a shop. My local TBHP gang even named me “Gum Vyapari graaja” (gum merchant graaja)

[graaja]

The last and most important part (and the toughest part as well) of the DIY is the BCM upgrade and changing the wiring harness. I will try to provide as much information as possible. But as there are so many things to explain, I may fall short on some points or pictures.

Wiring Changes

Let’s now get into the wiring details. I do not have access to detailed schematic diagrams. I just followed the instructions given by ciclo to the ‘t’. So, I will just provide high level details from what I understood (I may be wrong on some assumptions)

In the Indian Polo, the headlight switch directly controls the low beam, high beam and parking signals. In addition, the high beam is also controlled by the indicator stalk for flashing. With this new installation, the BCM will take input from the Auto light switch and the rain light sensor and control all the signals in the headlights – low beam, high beam, DRLs, and the cornering lamps. This is achieved by a combination of various wiring harnesses.

Let's take a look at connection details of each wiring harness

Below picture shows the 10 pin to 14 pin connector details.



The low beam, high beam and the turn signals are taken from the existing 10 pin connector. The DRL, parking and cornering lamp signals are directly connected to the BCM. Earlier the fog lights used to be driven by the BCM. This has to be isolated and the fogs now are driven by the headlight switch through a fuse. The picture shows Pin #8 as fog light connection. This is in the headlight switch connector that comes with the car. In the new wiring, this has to connect to Pin#3 of the red connector.

Following are the pictures from ciclo’s detailed instruction document. There were 4 assemblies in his wire set.

Below picture shows the CAN signals that need to be connected from the BCM to the instrument cluster connector.


Below picture shows the connections from BCM to fuse box. One of the relays had to be removed and shorted with a bridge.


Below picture shows the connections from the light switch to the BCM. The wires from the existing headlight connector had to be removed and transferred to the new red connector.


This wiring is also part of the headlight switch wiring. This had two relays. I had to plug these relays in a blank slot in the relay carrier.


Finally, the fog lamp wiring scheme. As the existing fog lamp wiring has to be isolated. A new wire has to be connected from Pin#3 of red connector to a spare fuse in the fuse carrier and from there to the fog lamps.

[graaja]

The wiring DIY

Before we go into the wiring, following are the tools required.

Spline bit set to remove the driver seat. I will greatly recommend removing the driver seat for better access to the BCM area.


General tools. Terminal removal tool for removing terminals from connectors, knife, stripper for cutting and stripping wires and pliers.


Custom made terminal remover. Though I had got a terminal remover tool shown in the previous picture, for one terminal in the BCM connector, the terminal removal tool was too thick. That is when my friend Pandiyan came up with this brilliant idea of fabricating a tool from a small safety pin. Genius indeed!


A small multimeter for checking continuity between wires, continuity in fuses etc. Ideally, there should be no soldering involved. However for some connections, I had to do some soldering. For this I used a soldering iron, heat shrinking tubes and a hot air blower to shrink the tubes. A simple hand held soldering iron should be enough. If at all you do soldering, make sure that you use heat shrinking tube to seal the joint and add another layer of TESA tape.



TESA cotton tape and lots of wire ties. This is very important to isolate existing wires and insulating them. Do not use regular insulation tape. Also, once wiring is done, tie up all the wires in the BCM area neatly, so that they do not in anyway come in the way of the accelerator or brake pedals.


A head torch. I consider this a very important tool for this installation. While managing the tough wiring job, light is something you should not have to worry about.


Below are the key areas the wiring has to be done.

• BCM connectors: Refer to Gannu’s BCM upgrade thread where he has explained in detail how to access the BCM connectors.
• Relay carrier: There is no way to directly access the relay carrier. You will have to remove the headlight switch and peer through this opening to see the relay carrier. Then you should reach from below the steering column and remove the relay and install the bridge. For installing the two new relays, I lied down and accessed the area from below and plugged in the new relay in a spare slot.
• Headlight switch connector: This is by far the easiest one to do in this installation. Once the headlight switch is removed, the cable can be brought out on the side and can be worked in a more relaxed position.
• Fuse carrier: To remove the fuse carrier, the footwell light has to be removed, and the AC air vent for the foot well has to be removed. Once these two are removed, remove the two screws that hold the fuse carrier and carefully slide it down. Slide out the cover behind to expose the wires. I do not have pictures explaining this step though.

I could not take many pictures of the wiring process, as I was completely occupied with the complex wiring job. Below are some pictures I managed to click.

VERY VERY IMPORTANT, A THOUSAND TIMES OVER - FIRST REMOVE BATTERY NEGATIVE TERMINAL


Fuse carrier out


Instrument cluster out


New CAN bus wires inserted in instrument cluster connector


How to remove terminals from headlight switch. Insert the terminal removal tool, lift the tab with a small screw driver and pull out the wire.

Picture Source: Ciclo's instruction document

Headlight switch removed and terminals from headlight switch connector removed.


Wires from headlight switch connector transferred to the red connector in the new wiring harness.


Headlight switch wiring completed


Relay carrier with the new relays and bridge


BCM connectors wired


Fuse carrier wired


Almost 80% of the work was done in this position.




Scene of crime


Once all the wiring was done, next step was VCDS coding.

[graaja]

VCDS Coding



Following are the important steps in VCDS coding. As lots of details are available in the net, I will not give a step by step instruction on this. Refer to RossTech site for detailed instructions.

Key adaptation: The new BCM has to be adapted to the remote key(s). Key adaptation is explained in detail in Gannu’s BCM upgrade thread and also in Ross Tech site. Links below.

Gannu's BCM upgrade thread
Ross Tech Article on BCM Replacement
Ross Tech Article on BCM adaptation

Gateway Installation list: This step is also explained in Gannu’s BCM upgrade thread. Before starting the BCM swap, it is very important to note down the modules installed in the CAN gateway and enabling these modules with the new BCM. Below is the picture of the installation list in my GT.


Long Coding the BCM: The long coding for the BCM has to be set next. As this is a completely new BCM, ciclo sent me the long coding that I need to program into the BCM.

Long code for BCM: 3AB02BBF08A10000013806917CEB96905AC0672F600D304120 0000030000

Important Note: The long code here is just for reference. Though it may work for most cars under most circumstances, the coding may change depending on the car model and manufacturing year.

Long Coding the RLS: Next the long code for the rain light sensor has to be set.

Long code for RLS: 06302D

Again, this code may be different for different models and manufacturing year.

Next, there are many other features that may be enabled using VCDS.

Duration of Coming Home Lights

This parameter sets the duration the headlights remain on in the Coming Home feature. This setting can be found under Central Electronics -> Adaptation.


Duration of Leaving Home Lights

This parameter sets the duration the headlights remain on in the Leaving Home feature. This setting can be found under Central Electronics -> Adaptation


DRL Off When Turn Signal Activated
This is a cool feature found in many D segment cars and above. In daytime, when only the DRLs are on, turning on an indicator turns off the DRL on that side. For this Bit#7 in Byte#23 in the BCM has to be set. This bit can be accessed using the Long Coding Helper.



Speed Threshold for Cornering Lights

This parameter sets the speed below which the cornering lights get activated. This can be accessed through Central Electronics -> Adaptation - Channel 32. The default value is 40. I set this to 55.



There are many more features that can be enabled. Below are the links to these features.

Static cornering lights turn on while reversing
DRL off when hand brake is up
Steering wheel angle to activate static cornering lights
A single flash on the indicator when you want to thank someone (absolutely not useful in India )

Another interesting feature that comes with BCM Max is parking. If you turn on the indicator stalk after turning off the car, the DRL and rear parking light on the direction that the indicator is set will turn on. For example, if you set the indicator to right, turn off the ignition and remove the keys, the right side DRL and the right side reverse parking lights remain on. This is very useful when you park the car in a dimly lit road.

Once everything was complete, took the car to 3M and gave it a good wash.


Finally, the installation is complete!

[graaja]

The Results

Once VCDS coding is done, tidy up all the wiring with lots of wire ties, and close everything and enjoy the new headlights.

Below are some pictures of the GT with the BiXenons.











Below video shows the features of the BiXenons with BCM max

https://www.youtube.com/watch?v=vRBzYmTTXBI

I also did an alignment of the headlights. I have covered this procedure in the below post in my projector retrofit thread.

Projector Alignment

Below pictures show the low beam and high beam patterns. These are under exposed pictures to bring out the shape of the hot-spot and were taken before the alignment. So the right side light looks a little higher. I forgot to take pictures after alignment.

Low beam


High beam


The cutoff is no way closer to the very sharp cutoff with that bluish tinge we see in the after market projectors. Call it a biased opinion, but I found this be less distracting while driving. Earlier when I had the retrofit projectors, my eyes always used to focus and admire the sharp cutoff. But with the OEM projectors, the light spread on the road is even and there is no distraction. Also, the large part of the hotspot opens up only in high beam. This greatly reduces foreground light and increases distance visibility. Also the above pictures were taken at 25 feet. As the distance increases, both the high beam hot spots come closer. At about 60 feet, they merge into one big hot spot providing very good illumination. You can see this effect on distance vision in the below video.

There is another possibility for the not so sharp cutoff. Instead of going for the OE HID bulbs, I chose to go with Philips Extreme Vision 4800K HIDs. Maybe the bulbs also affect the cutoff properties. For now, I have decided not to over analyze and enjoy the fruits of labor

Below drive-by video shows the light output.

https://www.youtube.com/watch?v=mSA2A5qfpUw

Comparing this with the older projectors, the most important point is that the light spread is much even. In the retrofit projectors, there was lot of foreground light. Though this will result in a very bright low beam, because of the bright foreground light, the long distance visibility was highly reduced. In the OE BiXenons, the full strength of the hotspots open up only when high beam is activated. Because of long distance visibility has greatly improved.

Important Lessons from this DIY

Here is a list of lessons I learnt from this DIY. I am listing them for the benefit for others who plan this upgrade to save them some time and pain 

1. Be prepared for problems - lots of them: Once I decided to go ahead with the upgrade and started ordering components, I wanted everything to go smoothly and the whole upgrade completed within 4 weeks. However, every day and week brought in new problems (parts not available, parts getting stuck in customs, technical issues like the RLS sensor fixing etc.). At one point of time, I realized that a project of this size is not going to go totally without problems, and it is going to take time to sort out the problems. Once I realized this, I relaxed and started solving problems as they came. So, being mentally prepared for problems is very important.
   
2. Plan your purchases: It is cheaper to get the full headlight assembly that has all the necessary components than getting in parts. A full set saves lot of shipping cost. Also make a thorough list of all the components required for the install even before starting to order. As most of the components have to arrive from outside the country, even one missed component can cause weeks of delay which could get frustrating.
   
3. The only way to do the wiring is the hard way: When I was taking pictures for ciclo for making the wiring harness, I first tried to remove the trim below the steering wheel to have easy access to the BCM wiring and relay carrier. But after breaking a few locks in the trim, I found that the trim is an integral part of the dashboard and cannot be removed. The only way to do this DIY is the hard way – lying down and working in the cramped space behind the steering wheel. So, do not try to open up the area below the steering wheel.
   
4. Create a comfortable working position: The first day of the wiring, we tried accessing the area behind the steering by lying down with top half of the body inside the car and bottom half outside the car. This resulted in a very awkward angle and greatly restricted the use of right hand. So, on the second day, we decided to remove the driver seat. This would let lying down straight with the full body inside the car. This allowed a better access to the wires with both the hands. On a scale of 10, I would say this brought down the level of difficulty from 10 to 8
   
   
   
   Before picture from Gannu's BCM upgrade thread
5. Change that windshield: Plan for a proper windshield change and go for suitable rain light sensor. The Jetta IRVM is definitely wide, has a wider field of view and looks nice. But it is not worth the headache of the imperfect mounting of the rain light sensor.
   
6. Make sure all connectors are plugged in tight: After completing the wiring, the headlights were dead, and the VCDS autoscan threw up more than 15 errors with the BCM. Most of these errors were "+30 signal missing" which meant many of the modules were not getting supply from the battery. After one sleepless night, I did a thorough tracing of all the wiring in the morning and checked each fuse in the fuse carrier, but found everything to be fine. That is when I found that the white connector in the BCM was a little higher than the black connector. I had assumed that this was the way it was supposed to be. Just to make sure when I pressed the connector, I found it was not properly seated. I seated it firmly and all the errors vanished everything started working fine. So make sure that you fix all the connectors firmly.

Pending Issues:

There are two issues that I need to resolve which I will do in the near future once I have the components.

• The first is to change the windshield and fix the OEM rain light sensor and the IRVM. It may take a few weeks for the IRVM and the sensor to arrive. I will finish this once I have all the components. I will post an update once this is done.
• After installation, I found that the dimmer switch was not functioning. When I operated the switch, the brightness of the buttons and the instrument cluster did not change. Ciclo asked me to disconnect T73a/7 pin on the BCM white connector. Once I did this, the brightness of the instrument cluster now changes. However, the dimmer now also controls the brightness of the LED number plate lights. The solution to this problem is to isolate the number plate light signals from the existing wiring harness and connect them directly to T73a/7. He has sent me the new wire and it should arrive in a month’s time. I will fix this issue once I get the wire.

Future Plan:

Once all the pending issues are fixed, the next thing to do would be to install the AFS controller for auto leveling of the headlights. This will involve fixing a level sensor to the rear axle. The AFS controller will detect the angle of the car (depending on the presence of passengers and luggage in the rear seat), and automatically control the level of the headlights so that the lights do not glare oncoming traffic.

I also plan to add the BiXenons to the car's insurance. Have already sent a request to Bajaj Allianz, and the representative said he will send me details of documents required. I think this is very important considering the costs involved.

That’s all folks, I have on the OEM BiXenon upgrade.

[GTO]

Thread moved from the Assembly Line to the DIY Section. Thanks for sharing!

[Dr.Naren]

Thanks for taking the effort to put up everything in detail!! Going OEM way might be expensive, but there is no headache of dealing with warranty issues of after market projector setups.

Regarding the cut off being not sharp, these are OEM projectors and they do not come with "Clear Lens". So you don't get sharp cut off / blue colour like the after market projectors with clear lens. Anyways the output is very good and no need to break your head about cut off

[graaja]

Originally Posted by Dr.Naren

Regarding the cut off being not sharp, these are OEM projectors and they do not come with "Clear Lens". So you don't get sharp cut off / blue colour like the after market projectors with clear lens. Anyways the output is very good and no need to break your head about cut off

Ah. Thanks for clearing that. Now I will be able to get rid of that nagging in my head and sleep peacefully

[Dr.Naren]

Originally Posted by graaja

Ah. Thanks for clearing that. Now I will be able to get rid of that nagging in my head and sleep peacefully

Haha.. You can still get the sharp cut off by sourcing clear lens or polishing the OEM lens. But it's not worth and again not a good idea to play around with OEM optics, opening the headlight etc.

[sudeepg]

A beautiful thread and a superb DIY. I am very impressed with the work done. As someone who is looking to upgrade the lights of the S-Cross alpha, I believe the setup you have put together here has excellent lighting. Unfortunately, the options for S-Cross folks are limited to none.

I have a quick question though. How does the head lamp leveling work? Does that work seamlessly with this install?

[graaja]

Originally Posted by sudeepg

A beautiful thread and a superb DIY. I am very impressed with the work done. As someone who is looking to upgrade the lights of the S-Cross alpha, I believe the setup you have put together here has excellent lighting. Unfortunately, the options for S-Cross folks are limited to none.

Thank you very much for the kind words

The biggest advantage of VW cars is the modular design. Most of the upgrades are plug and play by connecting the new module to CAN bus and coding through VCDS. And the parts are also easily available.

Originally Posted by sudeepg

I have a quick question though. How does the head lamp leveling work? Does that work seamlessly with this install?

As of now, I have not yet implemented headlamp leveling. For this I need to install an AFS controller and a level sensor. The controller and sensor are designed to work seamlessly with the installed BiXenons. The controller measures the angle of the car at the time of starting up, and adjusts the leveling motor in the headlights to get the correct level.

[cunnuvila]

Amazing DIY upgrade, the key word here being 'DIY' ! The level of satisfaction is unparalleled when the results are so good! An inspiring post!

[swissknife]

Originally Posted by graaja

The Results

Important Lessons from this DIY

Here is a list of lessons I learnt from this DIY. I am listing them for the benefit for others who plan this upgrade to save them some time and pain

Pending Issues:

There are two issues that I need to resolve which I will do in the near future once I have the components.

• The first is to change the windshield and fix the OEM rain light sensor and the IRVM. It may take a few weeks for the IRVM and the sensor to arrive. I will finish this once I have all the components. I will post an update once this is done.
• After installation, I found that the dimmer switch was not functioning. When I operated the switch, the brightness of the buttons and the instrument cluster did not change. Ciclo asked me to disconnect T73a/7 pin on the BCM white connector. Once I did this, the brightness of the instrument cluster now changes. However, the dimmer now also controls the brightness of the LED number plate lights. The solution to this problem is to isolate the number plate light signals from the existing wiring harness and connect them directly to T73a/7. He has sent me the new wire and it should arrive in a month’s time. I will fix this issue once I get the wire.

Future Plan:

Once all the pending issues are fixed, the next thing to do would be to install the AFS controller for auto leveling of the headlights. This will involve fixing a level sensor to the rear axle. The AFS controller will detect the angle of the car (depending on the presence of passengers and luggage in the rear seat), and automatically control the level of the headlights so that the lights do not glare oncoming traffic.

I also plan to add the BiXenons to the car's insurance. Have already sent a request to Bajaj Allianz, and the representative said he will send me details of documents required. I think this is very important considering the costs involved.

That’s all folks, I have on the OEM BiXenon upgrade.

Thanks for a wonderfully documented upgrade! While this tempts me to attempt doing this to my car, I am a bit wary of the warranty clauses. Are you sure that the mechanical warranty would stay despite such changes done on the car?