535i (1991) Radio not working after battery re-charge

[mehmaz]

I had to get AA to jump start my battery, as it died with the lights left on. Now the radio is showing the word 'Code'. I have had no luck with the 5 digit code. I am aware that the radio must be on for an hour, before trying to enter the code. I have also tried to enter the code after leaving the ignotion key in position 1 (for over 1 hour), and the radio left on. I always hear a beep after the 5th digit is entered, whether I enter the correct code or not.

It may require a reboot (reset), almost like a computer. Would disconnecting the battery, and then reconnecting it do this, and possibly help.
I entered a bunch of codes, earlier on (it has been a couple of weeks), before I found the right code by contacting my dealer. Not sure if all those entries somehow jammed up the thing.

Hopefully someone out there "been there done that" and can help me with this.......Regards......

[SRR2]

You have the protocol a bit confused. At initial application of power you get three chances to enter the code immediately. If you don't manage to get it right, the radio will have to be powered up for an hour before it will permit three more attempts. It doesn't matter if you remove power after the three failed attempts, you will have to wait that hour.

Just leave the radio powered up while you use the car until you think it's been on for an hour. Then, next time you switch the ignition on, carefully enter the correct code. It ought to work.

[mehmaz]

Thanks. I tried, again, but no luck. I just hear the beep after entering the 5th digit. Frustrating!

[SRR2]

If you're sure you waited the full hour, the likely answers are that you don't have the right code or the radio has failed. Time for an upgrade to something a little more modern probably.