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Jetta/Golf headlight removal and OEM GTI HID xenon housing retrofit
This article shows how to remove your OEM headlights or swap HID xenon headlights onto your mk5 body Jetta or Golf (mkv/5th generation/A5 body).difficulty: 1/5
The wiring only applies to 2005.5-2009 models because the central electronics module was changed for 2010. Since you already know what your car looks like, this is how it'll look like with GTI HID headlights. GTI/GLI had different grilles so they don't look the same as a Jetta with HID.
The OEM HID xenon headlights were only available on the 2006-2009 VW Golf GTI and 2006-2010 VW Jetta GLI. While there is a 2010 VW Jetta Cup car TDI with the GLI seats/suspension/brakes/steering wheel/misc trim, it still doesn't get HID lights. The 2010 Golf is an mk6 and uses different headlights. The 2010 Jetta Sportwagen got mostly cosmetic changes to look like an mk6 so it also uses Golf headlights. It's even called Golf wagon in Canada and overseas. For a detailed list of differences and revisions in mk5 vs. mk6 and 2009 vs. 2010 TDI, see 1000q: mk5 vs. mk6 changes.
HID headlights are xenon gas discharge lights. The light comes from an arc of energy inside the bulb instead of a glowing wire heated with electricity inside the bulb. They are somewhat like fluorescent lights in that they use less energy once they're lit and need to warm up before reaching full brightness. It's normal for an HID bulb to be bluish for a second after turning them on before turning white. They also draw more electricity on startup to light the gas arc.
Do not put an HID bulb or conversion kit into the stock halogen housings. The reflector pattern is not designed to focus and control the higher light output from an HID bulb. This will produce unacceptable levels of glare, blinding other drivers and creating a potentially dangerous situation. While there are some cars which had stock HID lights in a reflector housing, the pattern was designed for it. Almost all HID use a projector lens because it's better at controlling the light and it can use a cut-off shield for bi-xenon high and low beam function. The cut-off shield flips up when you switch to high beams. While the OEM GTI headlights aren't the best HID lenses I've seen (my opinion of cutoff and dispersion), they're still much much better than a HID kit put into a halogen housing.
OEM headlight housings, plastic, and wiring is almost always better than aftermarket headlight housings. Aftermarket may look nice from a few feet away but cheaper housings usually have brittle plastic. As long as they are quality I wouldn't be afraid of aftermarket headlights but most are designed for looks, not performance. OEM headlights are also DOT approved and are guaranteed to pass any local or state inspection since they are an OEM VW part.
OEM headlights also have the option of adding auto leveling. This comes standard on GTI/GLI and is done through sensors on the front and rear suspension arms. If your car didn't have HID from the factory you do not have auto leveling on the car. To add this capability you need 2 sensors, the leveling control module, and the wire harness. Leveling sensors and headlight washers are required in some countries but not the US. In addition to not blinding other drivers you get to see a little dance each time you turn on the headlights when the headlights do a self check.
NOTE - lowered cars can cause the arm on the auto level sensor to pop out of alignment and bend the other way. The sensor is located on the front and rear suspension arm. If this happens auto leveling will be incorrect or disabled.
NOTE - when using HID you must disable the daytime running lights (DRL). The daytime running lights are the low beams run at reduced power. This will damage the xenon bulb and ballast which should be run at full power for the longest life. The procedure is at the bottom.
Getting true bi-xenon function
The headlight housings are bi-xenon headlamps but when installed in a car with halogen headlamps, without running the shutter trigger wires, they will only work as low beam xenons. The high beam will still be halogens. The shutter is normally down for low beam operation. When the trigger wire is powered, it flips the shutters up to make the same light bulb high beam. The trigger wire goes from pin 11 on each headlamp plug to a highline central electric control module (CECM). Only package 2 or cars equipped with factory foglights have highline CECM. Other cars have mid or lowline CECM. If you don't run the trigger wire to the CECM or don't have a highline CECM the high beam will be halogen only. If you don't have a highline CECM it doesn't matter if you run pin 11 to the CECM because it can't control the high/low beam shutters.
If you run the extra wire, with the headlights off, when you pull the control stalk to flash your headlights "flash to pass", the halogen high beams will turn on. This is because it's not good for the xenon lights to flicker on/off and they can't respond fast enough.
With the headlights on, if you pull the control stalk, the cut-off shutters will flip up to expose the lights to expose the high beams as long as you hold the stalk. When you release the stalk the shutters flip back down to the normal low beam spot. If you switch to high beams, the cut-off shutters will flip up and stay up.
The easiest way to know for sure if you have a highline CECM is to use VCDS and use it to look at the part number and see the tests at the bottom of the page.
High beam halogen and high beam xenon at the same time
It's also possible to have both high xenon and halogen beams on at the same time like shown right. Since there is a bunch of stuff not related to installing HID lights, it's in the article 1000q: high beam halogen with high beam xenon. You must have a highline CECM and the trigger wire installed.
Wire adapter vs. de-pin the plug
The HID headlight housings use a 12 pin connector and your stock halogen headlight housings use a 10 pin connector. You can either de-pin/re-pin your current plug into a 12 pin plug or buy a plug-play adapter. Either way you must still run the wire at pin 11 to have bi-xenon function. I suggest spending the money and buying the adapters because it'll make life easier. After buying extra pins, 2 plugs, and wires, you'll only save about $30 vs. buying pre-made adapters. Time is money too.
OEM level alternatives
In my opinion, the best OEM level alternative HID headlight housing is the Hella Dynabeams. These use a sensor to determine your speed and rate of turn to turn the headlight beam into corners. Both have dropped in price and are excellent choices for headlights. For some reason, they come in "turning without HID" and "no turning with HID". If you get these headlights I would get a cheap HID kit and put them into the turning headlight since that's the point of getting these over OEM. They require no wiring adapter but do need very minor wiring to attach the turning sensor. The beam pattern is supposed to be slightly better than stock GTI/GLI headlights. They can be purchased from from ecstuning or from oemplus.
Parts (thanks to maloosheck for the wire part numbers and wire diagram)
repair wire VW# 000 979 025 (if you want to run wires from pin 11 to the CECM for bi-xenon function)
1.5mm (minimum) wire, solder, wire stripper, etc.
ross tech VCDS interface tool
1 set HID lights:
from ecstuning (US spec), from ecstuning (eurospec)
(NOTE - be careful because many vendors sell just the housings for about $650, you also need ballasts, bulbs, and igniters for the light to work)
1 pair 10-12 pin wiring harness adapter from ecstuning, from kufatec
if you choose to make your own adapter:
-2x 1.5mm repair wires per set VW# 000 979 131 e (3 total if you choose to run the extra pin 11 wire to the CECM for bi-xenon function)
-2x 2.8mm repair wires per set VW# 000 979 225 e
-2x 12 pin plugs VW# 1j0 941 165
-terminal release tool
-butt connectors and crimp tool, shrinkwrap
repair kit if your headlight has broken tabs - from ecstuning (left side VW# 1k0 998 225), from ecstuning (right side VW# 1k0 998 226)
If you wish to add auto-leveling feature you must have the front + rear sensor, module, and wiring adapter. Kit from kufatec
ECS tuning wiring adapters pictured below. It has an extra wire for pin 11.
Procedure to install OEM HID xenon headlights on VW Jetta TDI or similar mk5 car
Remove the front bumper. See 1000q: how to remove the front bumper on VW Jetta for details.
Unclip the headlight plugs and remove the headlights. Many VW plugs are released by pressing on a tab. From the same orientation as the photo below, gently press the little tab (yellow arrow) a little to the rear of the car and to the right to lift a little hook-lock. Sometimes the hook gets stuck so pressing the plug in a little will help release the hook before pulling it out.
Each headlight is held by 3x T25 torx screws, shown below. Note the 19mm housing adjuster nut-stop on the 2 lower screws. These adjust the housing relative to the bumper/fender/hood.
Plug in the headlight wiring adapters and put in the new headlights. If you want to de-pin the plug yourself and not use adapters, see below, otherwise skip the below section.
DIY HID wire adapter by de-pin and re-pin the new plug
This section shows de-pinning the plug and connecting the extra wire for high beam xenon lights. Skip this section if you bought adapters.
First double check the wiring. Write down the colors of each wire and which terminal number it's plugged into. Brown is ground. Also note wire gauge (thickness). Remove the wires from the split loom, the black plastic protective hose. This will give you more clearance.
Release the pink pin lock on the headlight plug by sliding it a few millimeters out. Only slide it out 1 notch. Insert the terminal pin release tool and slightly/gently push each pin in before wiggling/pulling it out. An example of how to use the release tool is shown in the video below. The plug is different but the terminal pins are released the same way.
Assuming your wiring is the same (it should be for your 2005.5-2006 VW TDI), each wire on the 10 pin connector goes into the same number on the 12 pin connector. Write the color/stripe color of each wire before removing it! Pins 9 and 10 will have to be cut and spliced to smaller pins to fit in the smaller spots on pin 9 and 10 on the 12 pin connector.
I suggest using butt connectors and shrink wrap to splice in new pins for 9 and 10. To use a butt connector, first strip the wire. Then slide shrink wrap over the wire. Put the wire ends into the connector and crimp it using a crimp tool. Slide the shrink wrap back up and heat the shrink wrap to waterproof and seal it.
The 12 pin plug also has a lock that must be released before inserting the pins. Slide the entire pink center in the direction of the yellow arrow (opposite the stamped arrow on the pink part). When you're done inserting all the pins, lock the pins by pushing in the direction of the stamped arrow. There are 4x 2.8mm plugs which are the same as the existing ones. You'll need 2x 1.5mm plugs for the headlights and 1x 1.5mm plug for the CECM.
On my HID headlight housing, there was a small notch that prevented me from pushing the plug on more than halfway. I couldn't figure out how to release it so there must be some trick I'm not getting because my plugs were correct. In any case, I used a dremel to file it down (yellow arrow below). I suggest filing it down on the headlight housing instead of cutting the 12 pin plug because there's more room. It's possible I didn't slide the lock up which was preventing the plug from fitting but I already filed it down so I don't know.
If you don't have a highline CECM or have a highline CECM but don't plan on connecting the extra wire for the high beam shutters, skip the below section. Again, to make the high beam shutters work you must connect pin 11 on each headlight plug to the CECM. Lightly seal the empty holes and pins 9 and 10 with silicone or other sealant to weather proof it. If you add pin 11, wait until you're done before weatherproofing the plug.
Running pin 11 to the highline CECM
Place 1 more pin at #11 on each plug and weatherproof the plug with silicone or other sealant. Leave enough wire on the pin to make it easy to connect later.
Remove the air intake box and battery box. See 1000q: air intake and 1000q: battery box removal for more details.
Punch a small hole through the main wire harness gasket at the firewall. Pass the wiring for pin 11 through the firewall.
Inside the car, remove the panel under the steering column (2x T20 torx screws). Also disconnect the footwell light and obd2 diagnostic port plug (the purple thing).
Slide the 2 red lock levers on the CECM to the side (yellow arrow below) to release the plugs. Remove the plugs. The plugs have short, stiff wiring, so it's pretty difficult to get them mixed up. Plugs A and D are outlined. You can also see "A, B, C," etc. on the CECM.
On plugs A and D, pry the pink lock out (yellow arrow below) by about 2 millimeters to release the pins.
Insert pin 11's wire from the right headlight into......
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