Is your Audi A4 key fob looking a bit dated? Many Audi B6 owners feel the same way. Fortunately, upgrading to the more modern-looking B7 key fob is a popular and achievable DIY project. Inspired by the pioneering efforts of Audi enthusiasts like audibmi, Hamotee, lanman1, aLeXliu911, and sandspeed, this guide will walk you through the process of swapping your old B6 key fob internals into a stylish B7 key fob shell. While this modification offers a fresh aesthetic, remember to proceed at your own risk. This guide is based on successful implementations, but we cannot guarantee compatibility or success for every vehicle.
Tools You’ll Need for the Audi Key Fob Swap
Before you begin, gather these essential tools to ensure a smooth key fob conversion:
- Torx Driver #6
- Torx Driver #8
- Philips #0 Screwdriver
- 1/16” Pin Punch
- Small Pick Tool
- Small Hammer
- VAG-COM Tool (for reprogramming)
You will also need to acquire a B7 key fob. eBay is often a good source for these, with prices varying depending on whether they include an uncut blade and a virgin immobilizer. Dealer options are available but are significantly more expensive.
Alt text: Side-by-side comparison of an older, bulkier Audi B6 key fob next to a newer, more streamlined Audi B7 key fob, highlighting the design differences.
Step-by-Step Guide to Swapping Your Audi A4 Key Fob
Follow these detailed steps to carefully transfer your Audi A4 B6 key components into a B7 key fob casing.
Dismantling Your B6 Key Fob
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Separate the Key Fob Halves: Use a small flathead screwdriver to gently pry apart the two halves of your original Audi B6 key fob. Start at the key ring area and carefully work your way around the seam.
Alt text: Close-up view of a hand using a small flathead screwdriver to open the seam of an Audi B6 key fob.
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Remove the Audi Logo and Screw: Once open, locate the Audi ring logo on the key head. Use a pen knife or thin tool to carefully lift off the logo. This will reveal a small Philips head screw underneath. Remove this screw.
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Separate the Key Head Halves and Locate Transponder Chip: After removing the screw, the two halves of the key head should separate. Inside, you’ll find a recess containing the transponder chip.
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Extract the Transponder Chip: Using the small pick tool, carefully pry out the transponder chip. It is usually pressure-fit and not glued, so gentle leverage should be sufficient. Handle this chip with utmost care as it is crucial for your car to recognize the key.
Alt text: Image showing the inside of a disassembled Audi B6 key fob head, pointing to the location of the transponder chip.
Alt text: Detail of a pick tool gently lifting the small, black transponder chip out of its housing within the Audi B6 key fob.
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Remove the B6 Key Blade (Optional): If you plan to reuse your existing B6 key blade, you’ll need to remove it from the flip key base. Use the 1/16” pin punch and a small hammer to tap out the roll pin holding the key blade in place. Locate the small hole on the flip base and gently tap the pin out from the opposite side.
Alt text: Comparison image showcasing the subtle difference in the shank size between an Audi B6 key blade and a B7 key blade, highlighting the area that might need modification.
Preparing the B7 Key Fob
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Open the B7 Key Fob Battery Compartment: Use a coin to pry open the battery cover on the B7 key fob.
Alt text: Hand using a coin to open the round battery cover on the back of a B7 style Audi key fob.
Alt text: B7 Audi key fob with the battery compartment cover fully removed, revealing the battery and internal components.
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Remove Screws and Separate B7 Key Fob Halves: Use the Torx screwdrivers to remove the three screws holding the B7 key fob together. The larger screw is a Torx #8, and the two smaller ones are Torx #6. Once screws are removed, carefully separate the two halves of the B7 key fob.
Alt text: Close-up showing the location of the three screws on the B7 key fob that need to be removed for disassembly.
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Remove the Circuit Board: On one side of the B7 key fob, you will see the IC circuit board for the remote functions. Carefully pry out this circuit board. It’s advisable to ground yourself to prevent static discharge, which could damage the board.
Alt text: Image showing the delicate circuit board being carefully lifted out of the B7 key fob casing.
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Locate and Open the Transponder Chip Cover: After removing the circuit board, look for a light gray cover in the upper corner of the key fob housing. Use the pick tool to gently pry up this cover.
Alt text: Detail of a pick tool opening the small, light gray cover that protects the transponder chip housing within the B7 key fob.
Transponder Chip Swap
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Remove B7 Transponder and Insert B6 Transponder: The gray cover reveals the location of the B7 transponder chip. Remove the B7 transponder chip and replace it with the transponder chip you removed from your original B6 key fob. The B7 key fob housing is designed with clips to securely hold the transponder chip in place.
Alternatively, you could purchase a B7 key fob with a virgin transponder chip and have it programmed by a dealer. However, this DIY guide focuses on reusing your original transponder.
Key Blade Considerations
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Reusing B6 Key Blade (Requires Modification): The B6 and B7 key blades are similar and even share the same HAA engraving. However, the B7 blade has a smaller shank. To reuse your B6 blade, you will need to carefully grind down the shank of the B6 key blade using a Dremel tool to match the B7 shank size. This requires careful comparison and test fitting and might result in a slightly wobbly blade fit.
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Using a B7 Key Blade (Recommended): Ideally, obtain a B7 key fob with an uncut blade. You will then need to get this blade cut to match your car’s key profile. Finding a locksmith who can cut “sidewinder” keys might be necessary, as not all locksmiths or dealerships offer this service. Audi dealerships may cut key blades based on VIN, but there’s a risk they might provide a B6-style blade.
Reassembling the B7 Key Fob
Reassemble the B7 key fob in the reverse order of disassembly. Ensure all components are properly seated and the screws are tightened securely but not overtightened.
Programming Your New Key Fob with VAG-COM
The final step is to program the remote functions of your “new” B7 key fob to your Audi A4 using a VAG-COM tool. Follow these steps based on Ross-Tech Wiki:
Channel 021: Remote Control Matching
- Connect your VAG-COM tool to your Audi A4.
- Go to [Select] [46 – Comfort System] [Adaptation – 10].
- Enter Channel 021. [Read].
- Enter the desired memory position (e.g., “3” for position 3) for the new key. [Test].
- Press any button on the B7 key fob remote. The VAG-COM should change from “Not Recogn.” to “Recognized.”
- [Save] [Done, Go Back] [Close Controller, Go Back – 06].
Note: You can check existing key memory positions in Meas. Block 007.
Conclusion
Congratulations! By following these steps, you should have successfully upgraded your Audi A4 key fob to the more modern B7 style. This DIY project offers a cost-effective way to refresh your key fob’s look. Remember to take your time, handle the components carefully, especially the transponder chip, and enjoy your updated Audi A4 key fob.
