2004 Porsche Cayenne S immobilizer active. Can look and unlock doors with fob?

no by-pass order new fob and have programmed

Question edited for clarity.
Question moved from Cellphones category.

In a word, you can't. You own a very desirable, high end, luxury SUV that is protected by a highly advanced anti-theft system and immobilizer. It is all computer controlled by the chip in the key, the transponder in the steering column, the anti-theft module, the Body Control Module, the Engine Control module and all the sensors in the vehicle. When the car was new, it came with three full keys and a valet key.

Your dealership can supply a new key based on the VIN Number and reprogram the anti-theft system and immobilizer.

start by scanning vehicle for trouble code --fixing battery issue --resetting or reprogramming fob/security system

reprogram keys look online how to reprogram your fobs

As a security precaution only the drivers door will unlock unless you double click the unlock button the keyfob. Your dealer can also change this setting in the OBD. Will it unlock after double clicking?

unlock the door then press the lock button on remote and hold down for 20/30 secs.manual does say hold button.....

Insert key into door barrel or ignition lock and turn key, whilst doing this press the unlock/lock button, the led on the dash should flash to indicate this has initialised the key to the car, then remove key and test operation of remote. If this fails then a new remote plus coding to the car by your dealership is needed

stay inside

It's likely the fuse. The fuse diagram is in your owners manual. The fuse box is on the side of the dash when you open your driver's door. That should solve your issue.