hello i have a 1997 preg 1.8 hlx fiat bravo, think its classed as a mk1 isnt it? i only got 1 key with the car and its a blue one with a button on it. I press it sometimes and the red light comes on for a second and i want to change the batterys in it so i can get central locking i think it has central locking but i dont know. Soif i change the batterys in the key it isnt going to mess upnothing,like the code light when you turn the ignition on.I got a tiny small key for the fuse box,is that to disable the alarm if the remote key couldnt turn the alarm off. Is it worth buying batteries to try it out or wouldit cause problems if i take the key apart. Is the key the imobliser for the ignition so this wouldnt affect the alarm on the key. What type of batteries do i need is it 2 or 1, Thanks
General Batterys flat in key fob
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General Batterys flat in key fob
yep its a mk1.
you have remote central locking and an alarm, both operated by the key.
you can change the key batteries no problem, you need 2 x cr2016. it cant affect the immob (key code light) as that is a completely seperate system. you'll see the immob chip when you open the key.
dont press the button while the reciever on the car isnt recieving, you only have 256 presses with an almost flat battery until the reciever and transmitter become out of sync.
you have remote central locking and an alarm, both operated by the key.
you can change the key batteries no problem, you need 2 x cr2016. it cant affect the immob (key code light) as that is a completely seperate system. you'll see the immob chip when you open the key.
dont press the button while the reciever on the car isnt recieving, you only have 256 presses with an almost flat battery until the reciever and transmitter become out of sync.
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if it has one battery then change it with a same one type battery , that will do!
2 x cr2016 = 1 x cr2032 (16x2=32)
the 32cell battery sometimes has problems because it isnt as wide as 2 16cell batteries, meaning there is less pressure on the contact.
if your remote has a 32 and works fine then i would fit a 32
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Change it for like for like batteries mine are both CR2032 aswell.
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the remotes use a rolling code system, so the code changes every time you press the button even if the car doesn't recieve the signal. the car knows the rolling code sequence for each remote and it will accept any code up to 256 rolls after the last code it recieved. that is the main principle of all rolling code systems. it prevents people stealing your code with a grabber and using it to unlock the car.
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So your saying don't press the alarm button on the key 256 times when the car is out of range. When you said, when the receiver is not receiving, that confused me because how would we know when its not receiving besides the obvious. 
What about this Jug, I have two blue keys from new. Both keys work the alarm/rcl from new. I use blue key 1 for use with the car and hide blue key 2 for emergencies. Blue Key 2 is never used after car purchase.
I use Blue Key 1 256 times. Now i use blue key an additional time to reach 257 times, will this mean Blue Key 2 has now lost the code to the receiver?
What about this Jug, I have two blue keys from new. Both keys work the alarm/rcl from new. I use blue key 1 for use with the car and hide blue key 2 for emergencies. Blue Key 2 is never used after car purchase.
I use Blue Key 1 256 times. Now i use blue key an additional time to reach 257 times, will this mean Blue Key 2 has now lost the code to the receiver?
So your saying don't press the alarm button on the key 256 times when the car is out of range. When you said, when the receiver is not receiving, that confused me because how would we know when its not receiving besides the obvious.
What about this Jug, I have two blue keys from new. Both keys work the alarm/rcl from new. I use blue key 1 for use with the car and hide blue key 2 for emergencies. Blue Key 2 is never used after car purchase.
I use Blue Key 1 256 times. Now i use blue key an additional time to reach 257 times, will this mean Blue Key 2 has now lost the code to the receiver?
each key has its own rolling code sequence so that isnt an issue.
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i suspect the button is pressed too many times, for example if its left in a drawer the button can easily get knocked every time you open/close the drawer, and it could even be held on for days at a time. its hard to day really, but i dont think its a fault with the car, so assuming the remotes batery doesnt go flat the 256 presses issue seems most likely.
