Interesting one this

Had a Megane 1600 with the vvt engine. It's been having an intermittent flat battery issue.

Randomly the customer would come out in the mornings and the battery would be flat. Some mornings so that it struggled to crank over, other times so flat it wouldn't unlock.

We had it back in time and time again and couldn't locate the parasitic draw.

It also had an intermittent cutting out at idle issue, we had managed to improve that but not cure it, but we were concentrating on the flat battery issue.

My lad spotted something on a Renault forum for both these faults together being the camshaft phase sensor.

So we tried a new sensor (genuine) = Fixed!

Would you believe it

No,I can't believe it.How does a phase sensor cause a flat battery?

I've heard of this, I believe the cam sensor is only part of the fix, a software update is needed as well.

A good fix nether the less.

Yes that is half the answer, it will need a software updata as well.

Yes I have now read elsewhere about the software update to fix this.

So far, its not been updated, but no flat battery!

I can only assume the old software is leaving a current supplied to the phase sensor, (whether that is every time or intermittently I don't know) and the sensor as it has aged is allowing the current to track to earth and drain the battery overnight.

French in'it?