2008 BMW 335i Key Fob Programming: A Step-by-Step Guide

Is your 2008 BMW 335i key fob malfunctioning, or did you recently acquire a new key fob that needs programming? You might be pleased to know that programming your key fob for your 2008 BMW 335i can often be done without a trip to the dealership. This guide provides you with several methods to program your key fob, allowing you to regain control over your vehicle’s remote functions.

Method 1: In-Car Key Fob Programming

This method is straightforward and can be performed inside your BMW 335i.

1. Get inside your 2008 BMW 335i and ensure all doors are completely shut.
2. Insert your key into the ignition.
3. Turn the ignition key to position 1 (accessory position). This is usually one click forward from the off position. Do not start the engine.
4. Immediately turn the ignition key back to the off position. This step must be completed within 5 seconds of turning it to position 1.
5. Remove the key from the ignition.
6. Press and hold the unlock button on your key fob.
7. While holding the unlock button, press the lock button three times within 5 seconds.
8. Release both buttons simultaneously.
9. At this point, the doors should lock and then unlock automatically. This lock and unlock sequence confirms that the key fob programming has been successfully completed.

Method 2: Programming with a Working Key

If you have one working key fob and need to program an additional one, follow these steps.

1. Enter your BMW 335i and close all doors.
2. Quickly insert the working key into the ignition and turn it to position 1, then immediately turn it off and remove it. This should be done within 5 seconds to initiate the programming sequence. The next step must be performed within 30 seconds.
3. Take the key fob you wish to program and hold it near your left shoulder. This brings the key closer to the remote receiver antenna in many BMW models, potentially improving the signal during programming.
4. Press and hold the unlock button on the key fob.
5. While holding the unlock button, press the lock button three times.
6. Release the unlock button. The doors should lock to confirm successful programming.
7. If you have more keys to program, quickly repeat steps 4 through 6 for each additional key within the 30-second window.

If the programming is unsuccessful with the keys in one order, try reversing the order of key programming (e.g., program key 2 then key 1 instead of key 1 then key 2).

Method 3: Alternate Programming Method (No Working Remote Confirmation)

This method is an alternative if you are unsure whether you have a working remote signal initially.

1. Insert the key into the ignition and quickly turn it to position 1 five times in rapid succession.
2. Remove the key from the ignition.
3. On the key fob you want to program, press and hold the unlock button.
4. While holding the unlock button, press the lock button three times.
5. Release the unlock button.
6. If you have another key fob to program, repeat steps 3-5 within 30 seconds.
7. Finally, turn the ignition on to finalize the programming sequence.

Important Considerations

It’s crucial to understand that these programming methods typically program the remote control functions of your 2008 BMW 335i key fob – the buttons that lock/unlock doors and activate the trunk release. These procedures do not program the transponder chip that is essential for starting your car.

The transponder chip, part of the vehicle’s immobilizer system, requires specialized diagnostic equipment for programming. If you need to program a new key to start your 2008 BMW 335i, or if the remote functions are not programming using these methods, you will need to visit a qualified professional.

For transponder chip programming, or if you encounter difficulties with remote programming, it is recommended to seek assistance from:

• Your Local BMW Dealership: Dealerships have the necessary equipment and expertise to program all aspects of your BMW key, including the transponder chip.
• A Certified Automotive Locksmith: Many locksmiths specialize in automotive key programming and can offer a more cost-effective solution than dealerships. Ensure they have experience with BMW vehicles and immobilizer systems.

Troubleshooting Tips:

• Battery Condition: Ensure the batteries in your key fob are new and properly installed. Low battery voltage can sometimes interfere with the programming process.
• Procedure Timing: BMW key fob programming often requires precise timing. Carefully follow the time constraints mentioned in each method. If you are unsure, try the procedure again, paying close attention to the timing.
• Receiver Issues: In rare cases, issues with the vehicle’s remote receiver can prevent key fob programming. If none of these methods work, a diagnostic scan of your BMW’s security system may be necessary to identify underlying problems.

By following these methods, you can often successfully program your 2008 BMW 335i key fob yourself. However, remember the limitations regarding transponder chip programming and when professional help is necessary.