Leaving home lights.

Sep 16, 2019
20
1
Wiltshire
Hi all,

Not entirely sure what's happening, but as of recent (maybe 7 out of 10 times) the leaving home lights aren't switching on when it's dark upon unlock click however when I then click the unlock for the second time they then switch on.. I will add that the coming home lights are working as expected.

I've done a factory reset in the menu, no change.. tried from both keys still seems to be a problem and no error codes/messages are showing.

Any thoughts?

Thanks,
Gav
 
Sep 16, 2019
20
1
Wiltshire
Just wanted to bump this.. anyone have any thoughts? Seems to be happening almost everytime I unlock the car on first click then have to click a second time for the lights to come on whilst it's dark out.

Will add again that the coming home lights work absolutely fine.

Has anyone ever had the rain/light sensor replaced on a MK3 Leon, curious on the cost etc.
 

black_sheep

Active Member
Mar 10, 2013
671
276
I’m fairly certain that this is a feature if the battery charge state is low (also impacted by the colder temperatures). The battery management system will prevent auxiliary/lower priority power drains functioning, so that the battery has the best chance of starting the car - it’s primary role.

By pressing the buttons ‘twice’ you are over-riding this feature.

I expect that this feature will work after a long run once the battery is up to full charge.
 

chrisRibiza

Active Member
Sep 27, 2007
1,181
45
Newtownards, Northern Ireland
I’m fairly certain that this is a feature if the battery charge state is low (also impacted by the colder temperatures). The battery management system will prevent auxiliary/lower priority power drains functioning, so that the battery has the best chance of starting the car - it’s primary role.

By pressing the buttons ‘twice’ you are over-riding this feature.

I expect that this feature will work after a long run once the battery is up to full charge.
I’m 99% sure this isn’t the case.

If you press the button twice to get the lights on then lock the car then you unlock again the lights will come on, on the first press.

I suspect it’s just to do with the sensor knowing the lights weren’t on last time the car was used (in day light) so it doesn’t put them on automatically for you.
If you lock the car and the lights have been on then unlock, they will come on, on the first press.

Mine is a 2013 Leon which I’ve had since 2014 and has always worked like this.

Obviously if the OP is locking in the dark and they aren’t coming on when he unlocks then he may have a different issue.
 
Sep 16, 2019
20
1
Wiltshire
I wonder if it's something to do with the sensor storing memory like you say of daylight/darkness.. will do some testing.

I do however have my car booked in for a battery replacement next week so fingers crossed that will resolve it if not there may be a deeper problem and possibly the sensor needs replacing.. will add though that the sensor has no issues with recognising rain/water however since the colder weather has set in there has been more moisture on the inside of the windscreen so not sure if that is causing some confusion for the sensor.
 

chrisRibiza

Active Member
Sep 27, 2007
1,181
45
Newtownards, Northern Ireland
I checked mine tonight...... and I’ve had a new sensor as the original got broke during a windscreen replacement and both function the same.

Id say there is no issue with your sensor or battery, it’s working as it should.

I locked my car at 1pm (daylight)
Unlocked at 5pm (dark and lights didn’t come on)
Pressed unlock again (lights came on)

Locked the car at 5pm and left it until 7pm, unlocked and the lights came on.

The lights will only come on upon unlocking if the lights were on when it was locked the last time.
 

martin j.

Active Member
Feb 11, 2007
1,306
436
Fife
Sorry not so, moved the car 12.15, no lights on, daytime, just been out to put car up drive and on unlocking doors, presto, lights on. Light switch on auto.
 
Sep 16, 2019
20
1
Wiltshire
I checked mine tonight...... and I’ve had a new sensor as the original got broke during a windscreen replacement and both function the same.

Id say there is no issue with your sensor or battery, it’s working as it should.

I locked my car at 1pm (daylight)
Unlocked at 5pm (dark and lights didn’t come on)
Pressed unlock again (lights came on)

Locked the car at 5pm and left it until 7pm, unlocked and the lights came on.

The lights will only come on upon unlocking if the lights were on when it was locked the last time.
Interesting.. you would have thought though that when dark regardless if you drove/locked the car during daytime and your car is fitted with auto lights that the lights would activate when dark out.


Sorry not so, moved the car 12.15, no lights on, daytime, just been out to put car up drive and on unlocking doors, presto, lights on. Light switch on auto.
hmmm interesting.

I have no idea what to do in this case!
 

martin j.

Active Member
Feb 11, 2007
1,306
436
Fife
Not read back but have you checked the light durations in the settings? Could it be set to 0 seconds?
 

chrisRibiza

Active Member
Sep 27, 2007
1,181
45
Newtownards, Northern Ireland
I assume you replaced it yourself? Is the sensor glass?
No, Autoglass replaced it too but I watched them as they done it on the driveway.

Yes, the sensor is glass and that’s why mine was replaced as they cracked the glass removing the original one.

Theres a layer of silicone between the sensor glass and windscreen glass.

If your car is functioning the same as I describe I’d say it’s normal and a new sensor won’t change anything, mine has always behaved this way with old and new sensor.

Reason they had to replace the cracked sensor was due to my auto wipers not switching off.
 

martin j.

Active Member
Feb 11, 2007
1,306
436
Fife
Do the lights work on auto for normal situations? If they’re operating as expected would this not discount the sensor as surely there is only one daylight sensor?
 
Sep 16, 2019
20
1
Wiltshire
Apologies I haven’t picked this back up.. I haven’t replaced the battery or sensor as the auto lights have been working as expected until today.. drove car during the day mixture of drl and full lights due to it getting dark, got home locked the car.. popped out later when dark unlocked car and lights didn’t come on upon first click, press again and presto.. lights on.

Thought I’d test the above theory by going out later that night to see if they’d come on and nope, had to unlock twice for the lights to come on, started the car let it idle for a while then off locked up and went back in.

Couple hours later decided to do one more test and nope, has to press twice again for lights on.. seems like it could possibly be a coding issue or possibly a memory issue as the car has barely been used in the last 2 or so weeks, Who knows!
 
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