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Right, where to begin…. um, yeah, low beams on my ’06 Pontiac GP are acting weird.
Now for the details.
So this cars headlights (low beams) usually come on as the car is turned off, I suppose to allow you to see your way to the door at night, and then after a minute or so, they shut off. The Multi-function lever is set to Auto pretty much always.
Over the past couple weeks or so, the low beams have been turning back on on their own after the car is shut off, resulting in the battery draining, and in turn I have to charge it back up. After that, the car runs fine. When I first noticed the lights doing this, I went out to check them with the lever, making sure it was as close to OFF as I could manually get it, and after a minute or so, the lights came back on again. Sometimes it seemed to make a difference if the car was locked or not, as in the lights would stay off if the car was unlocked, but would come on if it was locked. This scenario has since switched itself up to where now it doesn’t matter if the car is locked or not, the lights randomly just turn on at their leisure.So what’s going on here?
I’ve checked the battery, it’s sound. The low beam relay is warm due to the lights being used. The only thing I’m personally not able to verify (as in I don’t know what to look for) is the whether or not the Multi-function lever is malfunctioning – as in possibly shorting out or something.Any help would be greatly appreciated! Thanks in advance.
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What’s the BCM?
And it doesn’t have any aftermarket stuff on it. The alarm system on it came standard.[quote=”TazarZero” post=171376]What’s the BCM?
And it doesn’t have any aftermarket stuff on it. The alarm system on it came standard.[/quote]
BCM is the GM factory computer.
Which have been known to cause all types of issues.
Here’s some light reading for you.
https://www.google.com/search?q=2006+Pontiac+Grand+prix+BCM+issues&ie=utf-8&oe=utf-8Thanks. Yeah, I had my own little light go off in my head saying ‘why not just Google what a BCM is’, and that was moments after I posted my reply. But thanks for the link anyway.
I need to look up how to test a relay, like what voltages to look for and whatnot, because the lights came on again today, so I pulled out the one that corresponds with them (can’t remember what it’s called, sorry) to turn the lights out. Then when I went to plug the relay back in, the lights came on instantly, without the car being turned on. I’m almost certain the relay’s the problem now, contrary to what I’ve heard about how they are supposed to function.
Possibly.
But then again you’ll need to check the control side of the relay to see if it is getting a input to energize the relay.On my car you are able to shut that function off so now the lights go on and off with the switch manually like the old days not automatically. If you are able to shut the function off then try disabling it and using the switch manually.
Just wanted to give an update to this issue…. It is RESOLVED.
The source of the problem was Micro Relay #35: HDM Module. Swapped it out for a new one and the lights work as they should now.
From what I’ve read, when these modules go out, their behavior can be erratic – as in they might not always shut off what they control, sometimes they may just act weird – as was the case for me.
Personally, it was a gut feeling for me to replace this relay as it had been replaced before. Last time, it was switched out because the low beams stopped working. The fuses were fine, so the next step up the ladder was MR #35.
In the future, I will inspect the wiring to see if there’s any reason for that relay to act up – my guess will be to follow up around the head lights and back to the fuse box. From the wiring diagram on this link, the wire to inspect closely is C12 – goes out to the low beams.
Hope this helps anyone else in the future!
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