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Pontiac Repair/pontiac g5 daytime running lights


QUESTION: just recently i notice that my drl's stop working. both the low and high beam head lamps work, the sensor works as it automatically turns headlight on and off... i checked the fuse in engine compartment fuse box and its good. i moved to Sweden so i am having to use the parking break a little more.. the brake light indicator does come on when you lift the brake handle and of course goes off when i release it..  there does seem to be a bit of play in the handle..
  so im wondering what the problem might be..   things are very expensive here and when dealing with a car made in the USA triple the cost.   one other thing, when i got the car inspected for use they made me take the amber bulb out of the headlight enclosures and i had to replace it with a clear bulb, problem is i could only find a single element bulb, so the turn signal works but the other filament for the running light (parking light doesn't work. Is it possible that might add to the problem?  any help you could give me would be greatly appreciated ...   as it is when i drive i have to turn on parking lights..  not a big deal, but when i get the car reinspected next fall it is likely to fail and then i either get it fixed or i don't get to drive it...   and of course i might not have parts available here and may need to have them shipped..

ANSWER: Hi Craig:

you said you checked the fuse? the drl fuse? does the indicator on the dash cluster go on to indicate the drl's are on? the drl's are controlled by the body control module and it turns on the DRL relay. that relay is part of the underhood fues box. It's not replaceable. it's a printed circut board relay. the drl's are tied into the parking lights too I belive did thsi happen prior to the bulb burning out or you replacing that bulb? Without looking at a schematic I can't tell you off the top of my head what the issue here is.
This is right out of our eletronic service info this is for a 2007 car you didn't state what year this was:
The ambient light sensor is a light sensitive transistor that varies its voltage signal to the body control module (BCM) in response to changes to the outside (ambient) light level. When the BCM receives this signal, it will either turn ON the daytime running lamps (DRL) or the headlights if the headlamp switch is in the AUTO position. Any function or condition that turns ON the headlights will cancel the DRL operation. With the headlight switch in the AUTO position, the headlights will either be turned ON or OFF, after an approximate 30-second delay depending on whether daylight or low light conditions are sensed. The DRL illuminates the park/turn signal and DRL lamps. The DRL will operate when the ignition switch is in the ON position, the gear selector is not in the PARK position, and the parking brake is released. When these conditions have been met and the ambient light sensor indicates daytime conditions, the DRL will illuminate.

DRL operation in manual transmission equipped vehicles will occur when the ignition switch is in the ON position, and the parking brake is released.

Good luck :-}

---------- FOLLOW-UP ----------

QUESTION: thanks for the quick response.. the car is a 2008 g5 gt...   i cant ever recall seeing an indicator go on on the instrument cluster. I can tell you that the light sensor does work, because it will shift between light and dark.  when its light outside it changes and of course things look brighter (like the odometer reading and stuff like the time on the radio clock.) when i get a chance im going to put the double filament amber bulbs back inside the headlight enclosure..   As far as the fuse goes yes it was the DRL fuse under the hood. its a 10 amp..  im really hoping that it ends up being the bulb issue where as i only have a single element in there right now..   so where exactly is this printed circuit board relay you talking about? do i have to buy an entire card if it is bad??   I will follow up after i replaced the bulbs i had to take out....

ANSWER: Yes some of the relay are intrigal to the under hood fuse block and the DRL printed circuit board is part of the fuse block it's not replaceable.

---------- FOLLOW-UP ----------

 I put the dual filament bulbs back in the headlight enclosures so i now have amber parking light and turns signals..   This did not correct my problem with the daytime running lights..   however, the light sensor on the dashboard may be failing.. i keep the car in a parking garage, so when i turn on the car it doesn't sense enough light so the headlight taillights ect all come one..  i took the car out this morning and drove it for 25 minutes in lots of sunlight and it never shifted over to daytime mode, the instrument cluster lights stayed on as well as the indicator for the radio/clock.   i could shift it to daytime mode by turning the switch on the turn signal lever to automatic light mode off, when i did this instrument panel went out and the display on the clock and radio got brighter..   daytime running light did not come on.. when i turned automatic light back on everything came back on headlight taillights instrument panel and of course clock on radio was a little dimmer (i guess because thinks it dark and doesn't have to be so bright)
 so i tested the sensor, the only way i got it to shift in automatic mode was to hold a flashlight directly on it and after about 30 seconds it shifted and turned off the headlight, parking light display panel ect. but no daytime running lights...  im perplexed... oh yes the headlight work fine, both filaments are good, not sure if i mentioned that or not..  having electronics training in the navy i am familiar with intermittent electrical issues..   So what do you think? can it be the sensor is shorting out? could it turn off the headlight and all the other stuff but not activate the daytime running lamps? or is it something more?
   this circuit card under the hood, is it part of the fuse block? is it something that fails often? i take it that it isn't replaceable so does that mean if it ends up being the issue do i have to replace the entire fuse block? if it might likely be the sensor, how difficult is it to replace? I'm thinking the dash probably has to be taken apart??   im glad it is almost winter here and i will only have about 4 hours of daylight here real soon so driving with the headlights and stuff on all the time happens anyway..
thanks for your help and i look forward to your replay..

Well you have done a pretty good job here doing what you can to tryto figure it out sort of changing parts not there is not much more you can do. Yes the underhood block has to be replaced if that relay is bad. BUT I'm not going to tell you to do that they are expensive and it may not be the issue. Yes they do go bad for all kinds of issues. with out the air of a true scan tool there is not much else you can do . you need a scan tool to see what the data list for the BCM is seeing both input to it and output to control the relay.

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Todd Puccio


General auto repair,electrical issues,driveability issues,anti-lock brakes,SIR systems,HVAC,engine performance,Gm specific. I have worked at my current dealership since the 1990 model year anything much older than that I have limited exposure to. I do not have very much transmission experience so those question you may want to ask of another expert. When you send me a question let me know the exact make/model/engine and year for the car or suv you have it makes it easier to answer the questions that way. If your happy with the answer I gave you please feel free to Donate. This is a free service to you and I am not compensated at all by this web site. I have 22 years of experience to share with you and my knowledge wasn't free to me. I had to pay for my education.


Experience in the area: I have been a technician in GM dealerships for over 22 years and I am a ASE master technician. I work at a Buick and GMC truck store Previously I worked at a Pontiac GMC store for 18 years. I Served a a lead technician when dealership was on a team system. I just recently moved to a Buick,Hummer,Saab Store when my franchise was purchased by this dealership. Organizations: ASE master technician


Education/Credentials:High school diploma,2 year vocational school degree 2 year college degree. Associates degree in applied sciences (auto technology)Awards and Honors: GMC master technician

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Master GMC truck technician Master ASE technician in 9 categories

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