Help

[PaulH]

I have heard a rumour that if you disconnect your battery then you can only start the car after re connecting the battery, with the master key. Is this true ?
I will be travelling in my car shortly but was only goin to take the blue key.
i dont think this is true but can anyone shed any light on this ???

Thanks

 

[alan]

no problem

the codes in your ecu is perminant it wont ever be lost just make sure when the battery is reconnected the ignition is off the electronics dont like it very much if the get a jolt when you reconnect with the ignition on so dont do it ..the master key is only for recoding new keys so dont lose it or use it its not cheap to replace

 

[Nick]

Not true - probably

If you have the Haynes manual for the Brava it says in there that it is possible for the ECU to forget the codes after the battery has been disconnected.

I have disconnected my battery several times and had no problems so I suspect that they are just covering themselves against possible lawsuits.

Without knowing exactly how the codes are stored it is not possible to say if the codes can be forgotten in the normal course of events. If I was designing the system I would store the codes in a non volatile memory such as an EEPROM which should hold the code for 10000 years without problem, but having said that, any chip can fail, and the most likely time for this is when you turn it on. But chips are very reliable these days.
You can get "code savers" that plug into the cigarette lighter which supply 12v for keeping systems running when the main battery is disconnected. If you are worried it might be worth making up one of these, but if you are having any arc welding done on the car I think it would be better to have the battery disconnected and no power on any systems to try and reduce 'spikes' upsetting any electronics.

Does this help? The short answer is that in 99.99% of cases there will be no problem.

 

[PaulH]

Thank you

I didnt think it was true but just got a little concerned. Thanks for taking the time out to reply

PaulH

 

[Steve Roberts]

Don't forget radio code!

If you disconnect the battery, you will need the code for your radio, otherwise you won't be able to use it again!

Steve

 

[Nick]

More on radio codes

If you have forgotten your radio code, it can be supplied by the Fiat dealer. It takes them a few days but it arrives eventually.
Alternatively, you can have the code reprogrammed at some local audio shops - they may have to send it away. Costs between 20 to 30 quid.
If you do some web surfing you can find people who will come to you and reprogramme them. Sites like these tend to be closed down on a regular basis!

 

[Chris]

Disconnecting the battery

I read earlier in the forum that you can get alternative 12v power supplies that plug into your battery to preserve your radio code when you disconnect the battery.

Does anyone know how much these cost and where you would get one?

Cheers

 

[Brian]

vehicle memory saver

you can purchase a vehicle memory saver at most Halfords. Made by Gunson's, they're £20 or less. I've not had the need to use one but as they plug into youir cigar lighter (who smokes cigars these days!) then beware of a poor contact or moving it whilst the battery is off as it's not the greatest of electrical connectors!