2002 E320 Locks or trunk release not working!! :(
If that rear trunk lock is "frozen" - don't break a key forcing it.
Use a penetrating lubricant like WD40 spray the sh*t out of it - wait 10 minute - then try to loosen it a little with the key - do that again/again/again/again at 10 minute intervals until the lock cylinder breaks free - again, DON'T BREAK OFF YOUR KEY
1) For your reference - you can download the Owners Manual for your 2002 E-Class from the mbusa.com website under Owners Section.
2) I have attached the correct page from the Owners Manual - please see attachment - key needs to be turned left to approx 10:30 position - and pushed in at 10:30 position will unlock trunk
3) If your key won't turn the lock - you need two things -
a) a Penetrating Lubricant Spray Can with small tube to spray into the lock - like PB Blaster from a auto parts store or Break Free from a gun/sports store - a local auto parts store or gun store
b) PATIENCE - or you will break the key off if the cyclinder - spray the sh*t out of the lock - wait 10 minutes - work the key with even pressure towards 10:30 - after 2 minutes of that - spray the sh*t out of the lock again - wait another 10 minutes - work the key with even pressure again - repeat - repeat - after 4 or five times (don't LOSE patience) - if it is not free spray the sh*t out of it again - and come back 2-3 hrs later - work it again - if still frozen spray the sh*t out of it again - walk away - get drunk - pass out - and try it when you wake up in the morning and it will be easy to unlock.
If that works, you'll need to do that to open the trunk again after the trunk is closed.
It's likely that the stuck close problem might be caused by a loose wire on the trunk's locking electrical switch that you see at the bottom of the trunk lid when the trunk is open.
The spring loaded locking electrical switch is used in the locked position to disable the trunk's light when the trunk is opened for long period of time to save the car battery's juice. The switch turns off the light when the trunk is closed.
Each time the trunk is slammed closed, the wire/plug to the switch got shaken, loosened then one day, it dropped out.
Remove the trunk's cover, you'll see how to get to the switch and the wire/plug to it. It's tight space to work. A pair of long nose pliers can help gripping the wire to guide it back on the back of the switch.




