Front LED Running Light - Out

Celticxc60 · May 10th, 2011, 14:12

I was getting a bulb failure notice on display. Traced it to the LED running light (in my case offside). The manual states refer to dealer. I rang my dealer and they told me that I should check the corresponding side light as if that is blown the LED light goes out as well.
Did that and it was blown (a small 5w bulb). Changed that (I must say getting the headlight out was the easiest I can recall).
Now all is working again.
Passing this on in case it happens to anyone else.

Vecais · May 11th, 2011, 08:13

Luckily the LED lights rarely fail.

It seems that Volvo and other European brands have not mastered all LED lights. They add a small incandescent light to each circuit so that they can detect failures. The Japanese and Koreans seem to not have those problems.

Alec Dawe · May 14th, 2011, 07:30

I believe this is a wiring quirk related to earlier model cars like mine, and that the later cars do not have the LEDs out when the sidelight goes.
I can't for the life of me work out how Volvo managed to wire them up like this, they can't be in series, cos then you'd need a different voltage sidelight, not a standard bulb. Surely the LED's can not be wired through a current relay off the sidelight?
Anyone got any ideas as to how this circuit is configured?

wimorrison · May 14th, 2011, 08:24

I can see 3 valid reasons for doing this.

All LEDs require a resistor to drop the voltage to and Volvo could be using the bulb to provide this resistance and drop the voltage. This would have little effect on the incandescent bulb.

Another possibility is that it is difficult to see the side marker light and wiring them is series means that you will see that the bulb has blown but I suspect that the real reason is that the current draw on the LED is too low for the monitoring system to detect a failure and by including the side marker light in series it solves the first problem and enables the monitoring to function correctly.

One thing that I do know is that this is not a mistake, design fault or even a quirk. It will have been costed carefully and this will be the most cost effective wiring - car manufacturers worry about pennies when designing and building a car

tonyv · May 22nd, 2011, 06:36

Hi, I had an LED running light failure in late 2010 after 18 months ownership of XC60. Garage, Volvo Arnold Clark Aberdeen, repaired under warranty saying problem related to circuitry rather than LED light unit. Suspect my failure was not a one off isolated incident.

May 10th, 2011, 14:12	#1
Celticxc60 Junior Member Last Online: Aug 14th, 2021 11:47 Join Date: Jan 2010 Location: Farnham	Front LED Running Light - Out I was getting a bulb failure notice on display. Traced it to the LED running light (in my case offside). The manual states refer to dealer. I rang my dealer and they told me that I should check the corresponding side light as if that is blown the LED light goes out as well. Did that and it was blown (a small 5w bulb). Changed that (I must say getting the headlight out was the easiest I can recall). Now all is working again. Passing this on in case it happens to anyone else.

May 11th, 2011, 08:13	#2
Vecais Senior Member Last Online: Oct 9th, 2012 05:41 Join Date: Oct 2009 Location: Moving around, Australia	Luckily the LED lights rarely fail. It seems that Volvo and other European brands have not mastered all LED lights. They add a small incandescent light to each circuit so that they can detect failures. The Japanese and Koreans seem to not have those problems. __________________ _____________________ XC60 MY10 D5 auto AWD

May 14th, 2011, 07:30	#3
Alec Dawe Former Support Team Last Online: Jan 26th, 2024 11:26 Join Date: Jan 2006 Location: Nr Norwich	I believe this is a wiring quirk related to earlier model cars like mine, and that the later cars do not have the LEDs out when the sidelight goes. I can't for the life of me work out how Volvo managed to wire them up like this, they can't be in series, cos then you'd need a different voltage sidelight, not a standard bulb. Surely the LED's can not be wired through a current relay off the sidelight? Anyone got any ideas as to how this circuit is configured? __________________ Alec. (My other car is a WD 2-10-0)

May 14th, 2011, 08:24	#4
wimorrison Grumpy Old Sod Last Online: Dec 14th, 2021 15:39 Join Date: Jan 2009 Location: Hampshire, nee Scotland	I can see 3 valid reasons for doing this. All LEDs require a resistor to drop the voltage to and Volvo could be using the bulb to provide this resistance and drop the voltage. This would have little effect on the incandescent bulb. Another possibility is that it is difficult to see the side marker light and wiring them is series means that you will see that the bulb has blown but I suspect that the real reason is that the current draw on the LED is too low for the monitoring system to detect a failure and by including the side marker light in series it solves the first problem and enables the monitoring to function correctly. One thing that I do know is that this is not a mistake, design fault or even a quirk. It will have been costed carefully and this will be the most cost effective wiring - car manufacturers worry about pennies when designing and building a car __________________ Currently XC60 Previously XC60, V70, S40, ... Last edited by wimorrison; May 14th, 2011 at 08:27.

May 22nd, 2011, 06:36	#5
tonyv Tony Last Online: Jun 21st, 2023 17:54 Join Date: Jun 2010 Location: Alford	Hi, I had an LED running light failure in late 2010 after 18 months ownership of XC60. Garage, Volvo Arnold Clark Aberdeen, repaired under warranty saying problem related to circuitry rather than LED light unit. Suspect my failure was not a one off isolated incident.

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