Many new Porsche models have buttons on their keys that operate similar to a keyless entry system. These keys give users the ability to lock and unlock their vehicles manually (using the key) or remotely (by pressing a button on the key). Whether you drive a Porsche Boxster or a Cayenne, have a factory-installed keyless entry system or had one installed after purchase, all remote systems work in basically the same way: by transmitting a radio signal from the remote to your vehicle. If you're having trouble with your Porsche's remote entry system, try these troubleshooting tips.
Stand close to your vehicle (within 100 feet is recommended, depending on your remote's manufacturer) to test your key. Make sure no other vehicle is in the immediate area. Electronic signals from these vehicles have the potential to interfere with the radio signal transmitted from your remote. Try the lock, unlock and alarm buttons to see whether any of them works. If one button works, but not all, the battery is likely not your problem; skip to Step 5.
Replace the key's battery again. The battery you just replaced could be defective. Pop off the back of your remote key with a flathead screwdriver. This will expose the chamber where the battery is housed. Take out the old battery, and insert a new one (the size/style of your battery will depend on the model and year of your Porsche). Put the back on the key again. Test your key again to see whether it works.
Check for any dust or debris in the battery chamber. Using the screwdriver, open the key again. Look for any obvious signs of dust or debris. If you find anything, gently swipe the area with a dry cotton swab.
Look for signs of corrosion. Sometimes batteries can explode or leak inside a device, which can cause rust and other damage. If this is the case, do not try to remove the corrosion. Doing so could damage the radio transmitter and other electrical components inside the key. Take your key to a licensed Porsche repair shop; the professionals there may be able to clean it for you.
Examine the exterior of the key for any damage. You may have a jammed button that is interfering with the radio signal emitted by the key's transmitter. Dust and debris could be to blame; use a dry cotton swab to trace the edges of the buttons and remove the dirt.
Make sure the key is the problem and not the transmitter on the vehicle. Because the key worked before you replaced the battery, this is an unlikely scenario, but it doesn't hurt to test it before taking the car to a repair shop. If you can hear a "clicking" sound on your vehicle when you press the "unlock" or "lock" button, your vehicle is receiving the signal from the remote. In this case, the problem is most likely your Porsche's transmitter and not the keyless remote.
If you have a second key for the same vehicle, see whether that remote still works. If it does, you at least know it is the first key --- and not the transmitter in the vehicle itself --- that is the problem.
Do not attempt to adjust any of the electrical wires or settings inside your key. This can damage sensitive parts. It can also nullify your warranty, leaving you open to paying the full cost of any repairs.