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Discussion Starter #1
I just recently traded my 02 GMC for an 02 Chevy. My GMC could disable the auto headlights by pushing the dome over-ride button four times, as most of you know. Well, my 02 chevy doesn't seem to have this feature. What is the deal???? It sure sucks not having the ability to kill the lights when you'd like too. Took it to the dealer and they were no help whatsoever, in fact they never could give me an answer as to why it doesn't work....some of the mechanics there never even heard of the dome over-ride trick:mad: . If anyone knows what I can do hear PLEASE let me know!! Thanks everyone!!!
J-HEFF
 

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My bet is you now have a Canadian built truck. The option to disable the automatic headlights is prohibited by Canadian law. My father-in-law has the same problem on his Canadian built 02 GMC
 

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Boondokr, FWIW, there is no Canadian law regarding the auto headlamps in Canadian built trucks. Canadian vehicles built after 1991 must have DRL's and they must be illuminated in the daytime. GM must have their own reason for making Canadian built trucks this way. It is a real pita. I have spoken to their Customer Service and my dealer with no answer. Who knows???
 

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If your truck is not Canadian, are you pushing the override button fast enough? On my 2001, it only takes two pushes on the button - not four. If I don't make them quick enough, the lights don't shift to manual. I do this every morning at a security gate and at least one time out of five I don't shift first try because I wasn't quick enough on the two pushes. Give that a shot, just a hunch.
 

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Discussion Starter #5
Thanks for the reply guys....yeah, I think i'm pushing it right, I never had any problems doing it on my old truck, I've tried for like a half an hour while driving and nothing...it didn't even make the "ding" noise to let me know something happend. Well, if it is a canadian built rig, what the heck can we do to make the auto head lights be disabled?? Can you get a different wiring harness that allows the use of the dome over-ride option?

Thanks all, keep the ideas rollin'!

J-HEFF
 

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From my schemadics here, it looks like it's all in the headlight switch. So i'm assuming that you could just get a drl-on-off capable switch and it should work. I didn't know there was a difference until now, but in my alldata diagram it shows the drl wire as dark green, and the headlamp wire as white heading to the BCM. Inside the switch are the positions, AUTO-PARK-HEAD-DEFEAT. All of that through one wire, so once again i'm assuming it's all in the switch. Hell, get a switch and plug her in...if it don't work return it if possible. Maybe another 02 owner can compare switch part #'s with ya to confirm a difference.

-mike
 

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IIRC besides the switch you Might need a BCM reflash to American instead of Canadian to make the lights work right.

Not positive but I think I read that somewhere.

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underboost,

On your schematics do you happen to know which pair of wires on the light sensor on top of the dash control the Auto headlights at night for a 03.

There should be another pair in there also that have to do with the AUTO HVAC control.

And does it also say in there a way to disable the auto healight feature permanently, people have mentioned a paper clip would work to bridge the 2 wires on the sensor to keep the lights off until turned on Manually.

Thx for any help

DD

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Discussion Starter #9
Thanks for all the great help guys. I'm wondering if the dealer can re-flash from canadian to american ( I did look and the truck is Canadian), so I wonder if a dealer can help me out there. What do they charge for a reflash though, if it even would work??
Thanks everyone!!!
J-HEFF
 

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underboost,

On your schematics do you happen to know which pair of wires on the light sensor on top of the dash control the Auto headlights at night for a 03.

There should be another pair in there also that have to do with the AUTO HVAC control.

And does it also say in there a way to disable the auto healight feature permanently, people have mentioned a paper clip would work to bridge the 2 wires on the sensor to keep the lights off until turned on Manually.

Thx for any help

DD

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From what my manual says, there are two wires for the abient light sensor....White and Black. The white is the Ambient Light Sensor Signal, the black is Ambient Light Sensor Low Reference. I'm not sure about the bridge connection working there, but it also says that the drl defeat function occurs when the switch is put to defeat, which in turn grounds the drl switch signal citcuit to the bcm. Then the bcm gives manual headlight controls, disregarding the ambient light sensor etc. I guess you could try grounding the D-GN wire in pin 5 on the headlamp switch, which is the drl switch signal wire. It's C3 A8 on the bcm. If grounding that wire kills the drl's, then the switch is all that needs to be changed, and not any bcm programming, but, if it doesn't work, then i'd assume the bcm needs a little help in the matter via a tech2. I'd post the diagram i'm looking at, but alldata online doesn't have this particular diagram, or, i can't find it. I'm looking in my GM Service manuals.

let me know if there's anything else yall need. And if it works!

-mike
 
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