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Someone else has posted a very similar fault
This is a very strange fault because the uch controls whether the drl is on (presumably both go out when headlights are on?) but in both cases only one side is affected.
I can't help feeling it has something to do with the light sensing (behind interior mirror but this is all guesswork)
Is it possible to swap the bulb modules over between lights to see if the fault moves?

 

When my headlights are on the day running lights stay on too, think that's how they should be on the mrk 4. As for the modules i'm not sure , i've looked around and not seen modules for sale only the full light.maybe someone else has info on that.

 

are the lights sided or identical? I haven't yet had the pleasure of seeing one.
My thinking here is I'm wondering if it's a current monitoring issue or a control issue, I wanted to see if it was possible to move the lamp and see if the issue moved with the lamp. (I assumed it may have a replaceable lighting module, so much for saving the planet)

 

As you can see they are on with headlights on or off, i can't recreate the error with the light as its seems to be off intermittently.

 

I hadn't realised they were shaped like that! sorry, so obviously you can't swap them.
later edit but there are separate controllers and here so I suppose that's a good place to start
This has to be a control issue otherwise why would you need to open the door... just out of curiosity does opening the door without switching the ignition off provoke it back on?

 

No the light says off,its only when the engine is off and i've opened and closed my door and restarted the enginedoes the light come back on. When my engine is off and open the door to exit all my electrics like stereo, lcd screen goes off.Very odd. So those controllers attach to the light cluster and the leds on them send the light through the light cluster tubes?.

 

Presumably so as they appear to have surface mounted leds on them but I've not seen one for real.
If you have a multimeter and can measure the voltages at the plug that might give some clues at to whether it's the module at fault.
There must be another connector going into the lamp as it looks like that connector on the module picks up it's power from the lamp - if that connector mates with the lamp body?
Unplugging it might reset it so if possible I'd try to not to disconnect. Just changing the module would be easiest but it's an expensive gamble.

 

Hi
just had a thought, on some cars DRL's are directionally controlled by the steering try turning the wheels from side to side & see if they are steering orientated ?

Al

 

good point but afaik when that functionality exists it's only for parking at v low (almost no) speed.

 

Hi Wozz

OP initial post stated when stationary behind another vehicle, if about to turn the steering may not have been at centre position ?

Al

 

I was wondering if they were acting directionally but having to stop engine etc to get them working again isn't normal.
If they are directional, summat seems to be locking on'off

@steve....normal for DRLs to stay on when headlights on as they are also acting as sidelights.... but should dim...you may not notice the dimming, some still seem very bright to me at night.

 

I think the cornering lights (if that's what we are referring to) are the lower lights on the spoiler, which is what I thought the drl's were in the first instance (but I was mistaken). I don't think those drls have that functionality, afaik the only functionality is to dim when the headlights are on?

 

hi

perhaps the OP can test this theory, by starting the car and turning the wheels from sided to side whilst having someone observe the DRL's function.

l

 

I'll try that later with the wife turning the wheel.While out in the car today again the passenger side DRL light was off,while in traffic i turned the car off via the stop/start button and back on and the DRL came back on.

 

While turning the steering wheel left to right does nothing to my DRL, Both DRL stay on and remain on, no flicker or go off.

 

In my experience, DRLs will turn off when you use the left or right indicators. If you indicate left, your left DRL should turn off or dim. Could it be related to the indicators? Faulty signal?

 

My DRL's never turn off or dim when indicators are on.