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Shed Some Light On Daytime Running Lights

2004 Pontiac Bonneville SE

The daytime running lights should operate only the 2 high-beam headlight bulbs during daylight. A sensor on the dashboard turns on all lights (low-beam headlight & taillight) bulbs when it gets darker outside.

Does a burned out high-beam bulb default the DRL system to nighttime setting, turning on all the lights? I will soon replace the bulb, but I was wondering if there is another problem.

Has anybody run into this? Thank You, much!

I’d say you will find out when you replace the burned out bulb. I know you posted this question yesterday but I don’t think anyone responded. I don’t know the answer to your question. Please post back when you install the new bulb so we can all learn something.

“Does a burned out high beam bulb default the DLR system to nighttime setting, turning on all lights?” Did it?

I think not.

If you haven’t already replaced the burned out bulb, cover the low light sensor on the top of the dash and see if the lights come on.

Thanks For The Responses
I Replaced The Bulb

I knew the bulb was bad. Not only did it not light, but you could see through the lens, that the bulb was all clouded up.

The daytime running lights immediately worked (it was light outside). I threw my jacket up on the dash, covering the sensor and after a few second delay, all the lights came on. I took the jacket off and after a few second delay it went back to daytime running mode. So, I think it’s fixed. I’ll keep an eye on it for a couple of days just to make sure it’s not a red herring.

Well, how about that? Thanks, CSA, I learned something today!