The Lotus Cars Community banner

1 - 20 of 23 Posts

·
Registered
Joined
·
182 Posts
Discussion Starter #1
Out and about yesterday I could not unlock Elise with the key fob. Panic started to gnaw at the edges of my brain. Will I need a tow truck? I knew the other fob was not working. Abandoned far from home!

I popped the top on the fob and extracted the battery, which I rubbed on my shirt to get a quick charge. Upon reassembly, the fob worked again to unlock the doors and worked again to start the engine. No stopping until baby is safe in the garage. At the garage, I tried the fob and no go.

Purchased two 2032's and this morning installed the fresh batteries. Tried the simple fob resynchronization procedure but fearing I would need to reprogram the fobs. Both worked! Feeling fine.

Why did this happen? I had not changed batteries since purchasing Elise from Ferrari of Denver nearly 3 years ago. The manual clearly states 3 years is the expected life of the battery in the key fob. I had pushed the envelope!

:thwack:
 

·
Registered
Joined
·
4,713 Posts
Do the fobs always need to be re-synched when the fob battery is removed then replaced? Mine must be almost dead by now, and I have no idea how to re-synch them after they die.
 

·
Registered
Joined
·
2,875 Posts
I didnt need to resync when replacing the batteries
 

·
German Reimport
Joined
·
2,953 Posts
I bought a new battery and put it in the little tool pouch in the trunk.
That way - should the battery in the key fob ever die - I can still open the trunk to get to the spare. Better to have the alarm screaming at you for a minute or two until you get the battery replaced than to be completely stranded in the middle of nowhere -poke-
 

·
Forum Founder
Joined
·
29,081 Posts
Is it just me... I kept reading the thread title wondering how one makes a keyfob out of juice?
 

·
Premium Member
Joined
·
26,313 Posts
I bought a new battery and put it in the little tool pouch in the trunk.
That way - should the battery in the key fob ever die - I can still open the trunk to get to the spare. Better to have the alarm screaming at you for a minute or two until you get the battery replaced than to be completely stranded in the middle of nowhere -poke-
I carry two fobs. :eek:
 

·
Registered
Joined
·
9,786 Posts
I'm pretty sure the key fob's remote code is hard wired... so replacing the fob's battery doesn't change anything, therefore does not require reprogramming. The part of the system that can be reprogrammed is the Cobra box in the car... it can be reprogrammed to accept the codes from different fobs.
 

·
Banned
Joined
·
874 Posts

·
Registered
Joined
·
182 Posts
Discussion Starter #13 (Edited)
I did not need to program the key fobs.

I did need to perform transmitter re-synchonization, as described on pp. 35-36 of the 2005 Owner's Handbook, where it also says the normal operating life of the batteries is 3 years.

Juice is a many splendored thing; for sparkies, juice is electric current.

For others juice may well be an additive needed for screwdrivers.

Randy is right; I might better have said "key fob battery drained".
 

·
Registered
Joined
·
4,713 Posts
So are re-synching and re-programming the fobs the same thing? I'm still lost.
 

·
Registered
Joined
·
182 Posts
Discussion Starter #15
Re-syncing is not the same as re-programming.

Some one more knowledgeable may have a better answer, but I offer this --

When you press the appropriate button on the key fob an RF signal is transmitted, which the alarm unit will sense if in range of the signal. The content of the signal or the signal frequency must be recognizable to the alarm unit before its computations are triggered. Re-synchronization of the transmitters is a protocol that allows that to happen.

When you must use the PIN and re-program the fobs and the alarm unit, the process gives all pieces the appropriate content for transmission.

These are my speculations; do not mistake these ruminations for expertise!
 

·
Registered
Joined
·
182 Posts
Discussion Starter #20 (Edited)
Then -- It was a miracle!

I just reported what I did in the order I did it and offered a theory -- an accumulation of static charge, i.e., tribocharging.

Maybe there is another physical explanation.
 
1 - 20 of 23 Posts
Top