I was in a car park some way from home. I could not unlock my Passat – nothing happened when I pressed the door unlock although the lock and boot unlock buttons worked fine. What should I do? Obviously, try changing the battery. But it seems impossible to get the key fob apart. If you know the secret, it is easy and quick to do.
Note: do not be tempted to lever open the bottom end of the fob cover. It has a tempting groove, but it is not part of the cover release. You might wreck the cover and the fob won’t then go into the dash.
- remove the plastic emergency key from the top of the fob;
- slide the metal top of the fob sideways towards the emergency key release button; pull it off vertically;
- You will notice that one side of the plastic cover seems to have a hollow behind it. Insert a screwdriver carefully into one side of the open end, between the side of the cover and the white plastic moulding. Carefully lever this until it unclicks. Do the same to release the other side of the cover;
- You can now slide the cover downwards about a millimetre so that it releases and can be taken off.
You will now see the battery which is a CR2032 (readily available in newsagents, chemists, etc) for about £4.00
- Lever the battery out with a small screwdriver and put the new battery in, taking care to keep finger-prints off it.
- Replace the cover by putting the bottom end on first, sliding upwards slightly and pressing down into place.
- Replace the metal top by sliding sideways into position. Replace the emergency key.
The key should now work. I had to replace my battery after a couple of years of continuous use. Theoretically, you can take the external key cover off the driver’s door handle and use the mechanical key, but you need to press a release button in a slot underneath the handle and this seemed to be seized up.
Also, I didn’t have a screwdriver and so I opened the key fob with a teaspoon whilst having a coffee in Costa.