C70 Electrics : Battery flattening fault?

[Mike Hunter]

Symptoms are -

The red "I'm Locked" LEDs in the internal door handles stay on continuously (normally they go out after about 5 minutes).
Next morning the battery is completely flat.

This has happened a couple of times before, each time after a week or so of short runs (so the battery may have been a bit low anyway which could possibly have caused a malfunction). This time it has happened after a 50 mile round trip, so the charge should have been fairly good.

The battery itself is supposedly good - it is my wife's car and the first time it happened she took it to Halfords who (amazingly) declined to sell her a new battery after testing the current one, saying that it was "OK for another few years".

Anyone come across this before and have an idea on what might be causing the drain?

Thanks
Mike

[Clan]

Originally Posted by Mike Hunter

Symptoms are -

The red "I'm Locked" LEDs in the internal door handles stay on continuously (normally they go out after about 5 minutes).
Next morning the battery is completely flat.

This has happened a couple of times before, each time after a week or so of short runs (so the battery may have been a bit low anyway which could possibly have caused a malfunction). This time it has happened after a 50 mile round trip, so the charge should have been fairly good.

The battery itself is supposedly good - it is my wife's car and the first time it happened she took it to Halfords who (amazingly) declined to sell her a new battery after testing the current one, saying that it was "OK for another few years".

Anyone come across this before and have an idea on what might be causing the drain?

Thanks
Mike

The roof control module can drain the battery , so try a roof control module software upgrade first .

[Mike Hunter]

Thanks.
I think that the software is fairly up to date, but I'll rig up a meter and pull the roof fuses to see if that is it.

[Mike Hunter]

Thanks again! - it looks as though it *was* the roof causing the problem.

The car was left unlocked overnight and started OK this morning.
After a 25 mile run my wife checked the roof operation and it did not work at all.
She pressed the button in the boot opening and after that the roof worked OK and on locking the car the "I'm locked" lights went out as they should.

I seems that the button in the boot opening must have got knocked when she pulled out the shopping yesterday. We now know what to check if it happens again.

[Clan]

Originally Posted by Mike Hunter

Thanks again! - it looks as though it *was* the roof causing the problem.

The car was left unlocked overnight and started OK this morning.
After a 25 mile run my wife checked the roof operation and it did not work at all.
She pressed the button in the boot opening and after that the roof worked OK and on locking the car the "I'm locked" lights went out as they should.

I seems that the button in the boot opening must have got knocked when she pulled out the shopping yesterday. We now know what to check if it happens again.

There is a known problem with the roof control unit staying live , a software upgrade will fix this if it is your problem , I do not think this gets updated at the service .

[Mike Hunter]

When the car last went in to a main dealer (18-24 months ago) they said that they had upgraded "ALL" the software to the latest standard - sounds like they were fibbing and it had better go back again!

[Mike Hunter]

Originally Posted by Clan

There is a known problem with the roof control unit staying live , a software upgrade will fix this if it is your problem , I do not think this gets updated at the service .

Hi Clan

Can you throw any more light on this "known roof problem"?

The lock lights staying on is happening more and more frequently now.
We've contacted the main dealer in Winchester, who confirm that all software updates applicable to the car have been performed, but claim to have no knowledge of the "known fault", nor of a specific software update for the roof operation.

They *did* offer to do diagnostic work for an open-ended time at £132 per hour. How kind of them!

PS - I didn't make it clear above :

The problem ***IS*** definitely associated with the roof - fiddling with the roof always fixes it.