Modernising your vehicle's lighting is a popular upgrade, and converting from traditional halogen headlights to brighter, more efficient LED bulbs is a significant step forward1 . If you've experienced the brilliant illumination of LED headlights in newer cars, you know the difference they can make to nighttime driving1 . This guide, based on a DIY installation on a 2009 VW Tiguan, will walk you through the process.
Why Switch to LED Headlights?
LED headlights offer several advantages over their halogen counterparts
Brighter Illumination: They produce a piercing light, significantly improving visibility
Different Color Temperature: The whiter light produced by LEDs is often preferred by the human eye and can project light farther.
Longevity: LED bulbs typically have a much longer lifespan than halogen bulbs, potentially saving you money in the long run.
Choosing Your LED Conversion Kit
In this DIY project, I used two Philips LED headlight bulbs from AliExpress were used. Both are H7 types, suitable for the main and dip beams of the 2009 VW Tiguan.
Philips H7 Ultinon Essential G2 LED Headlight Bulb: This is described as Philips' entry-level LED headlight, costing around 40 Australian dollars1 . Each bulb features six LED chips (three on each side).
Product link: https://s.click.aliexpress.com/e/_mLS4j3q
Philips H7 Ultinon Pro 3013: Priced slightly higher at 53 Australian dollars, this bulb comes with more robust packaging2 . It appears to use more metal in its construction, potentially leading to better heat dissipation2 . The Pro version has a slightly lower color temperature of 6,000 Kelvin, which is expected to produce a wider light compared to the Essential G2's 6,500 Kelvin .
Product link: https://s.click.aliexpress.com/e/_mPOurha
Both bulbs have a maximum power output of 20 watts and operate between 12 to 24 volts . In the 12V system of the Tiguan, this translates to approximately 1.67 amps of current and a resistance of 7.2 ohms.
Preparing for Installation
Before installing the new LED bulbs, the old halogen bulbs need to be removed. This process is generally similar for most bulbs:
Remove the Rubber Cover: Locate and remove the rubber cover behind the headlight assembly.
Twist the Plastic Tab: Inside, you'll find a black plastic tab. Grab it and twist it in a counterclockwise motion until you hear a clip release.
Pull Out the Halogen Bulb: Carefully pull the halogen bulb out of its socket. This might be tight, especially if it's the first time . Using a plastic pry tool or a flathead screwdriver to gently pry the base of the bulb can help.
Remove the Metal Bracket: Retrieve the metal bracket that holds the bulb in place. Lift up the tabs on either side with a pick or pry tool and pull the bracket off.
Modifying the Mounting Bracket (VW Tiguan Specific)
For the 2009 VW Tiguan, a modification to the OEM metal bracket was necessary:
The center piece of the metal bracket needs to be ground off to create a larger opening to accommodate the stem of the LED lights. Alternatively, custom mounting brackets compatible with the Tiguan are available. The grinding approach was chosen because it maintains backward compatibility with the original halogen bulbs. When grinding, be careful not to remove too much material, as a central hole is needed to align the bracket with a plastic tab.
Assembling the LED Bulbs
Once the halogen bulbs and brackets are removed and the necessary modification is done, you can prepare the LED bulbs for installation:
Remove the Black Plastic Ring: Rotate the black plastic ring on the LED bulb counterclockwise until it can be pulled off.
Add Indentations: Create small indentations on the plastic ring at the 12:00 and 6:00 positions. This helps the ring stay in place when twisting the LED light. A small drill can be used for this.
Clean Components: Clean the bulbs, plastic rings, and metal brackets with an alcohol wipe to remove any contaminants.
Assemble: Align the indent on the plastic ring with the flat side of the metal bracket and the small tab on the metal bracket with a flat portion of the plastic ring. Hold them together and insert the stem of the LED bulb through the metal bracket. For the left-hand side headlight, position the wire at the 1:00 position; for the right-hand side, position it at the 7:00 position to avoid internal components.
Tighten the Bulb: Turn the bulb clockwise a couple of notches until the diodes are perpendicular to the tabs on the metal bracket.
Installing the New LED Headlights
With the LED bulbs assembled, you can now install them into the headlight assembly:
Loosen the Clamp Screw: Using a T20 torque bit (preferably with an angled handle for better access), loosen one of the screws that clamps the metal bracket into place. You don't need to remove it completely.
Align and Insert: Grab the LED bulb (remembering the correct wire position for each side) and align the metal tab with the bottom slot in the headlight housing. Slowly insert the bulb, looking at the front of the assembly to ensure proper alignment.
Tighten the Clamp Screw: Once the bulb is aligned, tighten the clamp screw back down to secure it.
Rotate for Correct Positioning: Rotate the base of the LED bulb clockwise until the step of the bulb is completely vertical.
Connect the Power Plug: Connect the power plug to the LED bulb, noting the polarity. A multimeter can be used to determine the negative terminal.
Reattach the Rubber Cover: Finally, reattach the rubber cover behind the headlight assembly. Repeat this process for all the remaining headlight bulbs.
Checking the Beam Pattern
After installing the LED bulbs, it is crucial to check the beam pattern to ensure they are similar to the original halogen bulbs. This is important for road safety to avoid blinding other drivers. In this case, the LED bulbs produced an almost identical beam pattern to the halogen bulbs for both low and high beams, which was considered acceptable.
Addressing CAN Bus Errors
A common issue when converting to LED headlights is triggering CAN bus errors, as the lower power consumption of LEDs can be misinterpreted by the vehicle's computer. In this 2009 VW Tiguan, CAN bus errors were indeed triggered:
• The high beams flickered briefly upon turning the ignition on.
• An error message appeared on the multifunction display, initially complaining about the dip beams.
• The control module picked up the high beam error only when the high beams were turned on.
While the headlights still functioned correctly, these error messages could be annoying and might mask other potential lighting issues. The video creator mentioned researching solutions to this issue as a future project, suggesting that CAN bus error correction modules or other methods might be needed to resolve this.
Conclusion
Converting halogen headlights to LED can significantly enhance your driving experience, offering brighter and whiter light. While the installation process can be straightforward, as demonstrated on the 2009 VW Tiguan, certain modifications or considerations, such as CAN bus errors, might arise depending on the vehicle. Always ensure the new LED bulbs produce a safe and appropriate beam pattern before driving on public roads. For specific products and tools used in this conversion, refer to the affiliate links in the video description.