Thread: how to change battery, anything special required?

Originally Posted by Eevo

hi all, i didnt realise leaving the doors unlocked causes drain on the battery.

Doors unlocked doesn't affect the battery.


Leaving the key in the ignition will though, as well as electrical interference as the BECM will not go to sleep.






You'll need the radio code & then reset all the windows & sunroof by cycling them fully open then closed.
The key will need to be re-synchronized to the car too.

Originally Posted by Scouse

Doors unlocked doesn't affect the battery.

oh i read that it would. moving on.

Originally Posted by Scouse

The key will need to be re-synchronized to the car too.

and how is this done?

I think it depends on your year model!

My '99 P38 has had the battery out multiple times. When it comes time to put the battery back in, I ensure the drivers door is open, but otherwise have never needed to re-sync keys or input radio codes! All I've needed to do is reset the windows.

Cheers
Keithy

Your right Kiethy I too have changed my battery a number of times (especially when I had rf problems) and never had an issue with anything except the standard windows and sunroof...........mine is a 2000

my battery has also been in and out many times,

the manual said to leave the drivers door open and the key in the ignition (switched off) tells the computer you haven't stolen the car, apparently.


I always do it just because it's easy enough and I also only have to reset windows and sunroof

mine is a 1995

I think leaving the car in anything other than Park will also flatten the battery. I think the BECM doesn't go to sleep.

I think it also depends on how long you have the battery disconnected.

It seems that if you are over about 20 mins ( the SRS discharge time) then you may need to re-sync the key but you always have to do the windows and sunroof.

Oh and leaving an OBD device connected can keep waking the BECM and kill your battery as well.

Steve

I've never had to re sync the key after having the battery disconnected. Apart from the straight forward windows and sunroof calibration I have found the most time consuming part to be reprogramming the radio stations after re entering the radio PIN. (1996 HSE)

Gary