Is it possible to remove the keypad and cross the wires momentarily in the back?

try 4444

If there were a default code every crook in town would have been in your garage. The best way is to call a garage door technician and let him do his thing. He can also install a keyed release that will prevent this in the future.

There is absolutely NO standard "in case of emergency" keyless code. That would be a severe security issue.

And most keyless entry systems are also wireless because of what hendricus said. If neither the keypad nor the remotes are operational, that is a sign that the circuit board has either failed, the machine is not getting power, or someone inadvertently erased all the codes or put the machine into "lock" mode via the inside, wall mounted button.

In a vaulted garage (no other access except through the garage door) you should have a Vault Release installed on the face of the door. You should see a small circular keyhole in the top or intermediate section that when the key is inserted, the tumbler will fall out which is connected to a cable that, when pulled, will release the carriage/trolley from the machine allowing for manual operation.

If you do not have a Vault Release, you will more than likely have to cut a hole in your door or bend back the top section to gain access to the manual release.

Please update us and let us know what your door is equipped with and what route you decided to go.