Removing the battery

MikeT · Post by **MikeT** » 14 Apr 2008, 11:53

I want to remove the battery to see if it'll hold a good charge but am concerned about what effects this may have. I don't (currently) have the radio code and what about the alarm/immobiliser, remote, keys, locks, ECU memory etc? Are any of those likely to require resetting and how is it done? The handbook details resetting the key fob but little else.

I'm familiar with a MK1 but there are some subtle differences with this Mk2 that I'd like to be aware of first.

Post by **CitroJim** » 14 Apr 2008, 20:10

As far as I can recall with mine Mike, it fairly looks after itself. The alarm might go off but the plip will reset it with no problem. Otherwise the old trick of holding down the ultrasonic defeat button will reset the alarm as you switch on the ignition.

A good power-off is good for the Engine ECU

MikeT · Post by **MikeT** » 14 Apr 2008, 23:25

Same as the Mk1 then.

I'm just a little cautious as there's no keypad and the manual refers to a chip in the key that may need reprogramming. When a car won't start, I will invariably consider the immobiliser a suspect. With the MK1 you had a red and a green light to know for sure, is there any similar indicator with the MK2?

Post by **CitroJim** » 15 Apr 2008, 07:44

The only indication you have on a MK2 that the immobiliser has de-set is by the lamp going out on the dash.

If you look to the left of the open door warning light in tacho, you'll see a an orange light with a key symbol in an sideways "U" light up briefly as the ignition is turned on. If this light stays on, the immobiliser has not de-set.

Disconnecting the battery will not require the key chip to be reprogrammed. It works like an RFID tag and it's a once only programming job. In my experience, the central locking/alarm plip does not need anything doing when the battery is reconnected. Believe me Mike, you're quite safe disconnecting the battery..

MikeT · Post by **MikeT** » 15 Apr 2008, 14:49

Right, battery's off the car and on charge. It looks a bit too small and underpowered (60Ah) but it holds a good enough charge, at least over two days so far.

So, how am I supposed to lock the boot now?

dnsey · Post by **dnsey** » 15 Apr 2008, 18:06

A bit late now, but you could have connected a spare battery (even a pretty useless one) in parallel before removing the original, just to retain the codes, etc.

MikeT · Post by **MikeT** » 15 Apr 2008, 18:15

Oh yes, I forgot about that trick. I've read that even a PP3 9V will work, how true that is, I don't know. In my case, I wanted to disconnect power while working in the engine bay anyway.

Post by **CitroJim** » 15 Apr 2008, 20:48

MikeT wrote: So, how am I supposed to lock the boot now?

That's a good point

MK2s don't have a key operated lock!

lock the car with the battery on but with the bonnet up, and the disconnect the battery...