Random Low Beam Xenon gremlins (both sides flickering then stay on)...

[Ricky Bobby]

Second time this happened in about 6 months, I'm going to scan with DIS but it is so weird.

Today I was driving for about 20 minutes, got off the highway and pulled up to an intersection, then my low beams (both) shut off, then flicked on again, then shut off, then flicked on again, and stayed on. Then I pulled up to another stoplight, and they did it again, this time 2-3 times. Then they stayed on but CHECK LOW BEAMS message came on. The lights stayed on until I got home 5 minutes later.

I just replaced the battery a month and a half ago, so it should be good. I didnt have OBC test 9 on so I couldn't see the voltage, is it possible the voltage dropped enough coming to a stop at the intersection that it shut the ballasts power down or interrupted them in some way? I guess if that was the case would I have some undervoltage codes?

Other than that no other lighting issues, and when I start the X5 up again, the CHECK LOW BEAMS is gone, so it only stays on during the drive cycle when it happens.

When I was at the second intersection, I was able to get the OBC test up before the error popped up and I was exactly at 13.0 volts. Usually I'm around 13.2-13.5 when driving.

Any ideas? I can post up the errors after I scan it tomorrow, it only kinda bothered me the first time it happened but since this is the second time I'm thinking something may be amiss. And I would troubleshoot one side but since literally both low beams go off at the same time, I don't think it has to do with both ballasts/bulbs at the same time.


UPDATE Post #31 - Starting with a newer passenger ballast to see if this cures the issue since it seems to be isolated to that side (although I think the few times where it ended up shutting down both was just the LCM freaking out)

[Joshdub]

Do you have codes for the LCM?

[crystalworks]

13.0v seems pretty low to me. Would expect a 13.5 to be within "normal" operating conditions, but even that could be higher I think. Can any other I6 owners verify voltage from a new battery/alternator combo? I'm guessing the M54 in these uses the 120A or 140A alternator?

[Joshdub]

Originally Posted by crystalworks

13.0v seems pretty low to me. Would expect a 13.5 to be within "normal" operating conditions, but even that could be higher I think. Can any other I6 owners verify voltage from a new battery/alternator combo? I'm guessing the M54 in these uses the 120A or 140A alternator?

I'm usually >13.5 with everything cranked, lights, fans, heated seats, ect. But when its really cold I notice a decrease. I don't know why but it seems pretty consistent. That's with a new 140amp and less than year old battery.

[Ricky Bobby]

OK so morning update: My 25 minute drive to work (20 miles or so), on the highway she was a consistent 13.5-13.6v, no dips - coming to a stop at the traffic light before my office and idling for a few mins it dropped down to 13.0-13.3, but went up a bit after that - so I mean for the most part the alternator is putting out pretty solid voltage which dips down when coming to a stop a bit, I just don't know what the safe "dip" would be - I mean anything under 13v is undervoltage from the alternator is that accurate?

I'll pull the codes later or tomorrow to see what was going on, got a little wintry mix coming our way later - but for the most part I'm just throwing ideas out there - and pretty sure I have the 140A alternator as well, especially since I have dual axle air suspension.

[Ricky Bobby]

Weird - I'm bumping this thread again since it happened to me again last night - mind you I had a fresh alternator and battery in the past year -

Basically what happened about 3-4 mins after starting the car last night, the front headlights went off completely (not sure to be honest if the angel eyes did or the turn signals), then came back on, then off a few seconds later, then on again, then off a few seconds later, then back on, and CHECK LOW BEAMS - even though the lights were back on at that point and stayed on - no error message before the 3 times they went off then ton.

Lights worked fine and fully operational the rest of the way home, voltage at 13.8-14.0v - Error on dash stayed on after shut down, then reset and nothing in OBC at next start up.

So weird.

[crystalworks]

Do you have a low beam retrofit of some sort RB?

Voltage looks much better @ ~14v so I think it's safe to rule out voltage issues now.

[Ricky Bobby]

Factory ballasts and 35w Philips D2S bulbs which have a few years on them - I was going to get Nightbreakers, maybe these are a bit old and pulling too much voltage from the LCM as they age -

To be honest though I recall this happening once before about 3-4 years ago before I even had any retrofit work done on my headlights - Its like a random LCM error because the lights are fine

[crystalworks]

Originally Posted by Ricky Bobby

Its like a random LCM error because the lights are fine

Could very well be. Or a ground issue to the LCM or something. See if you can pull any codes related to the LCM.

[Ricky Bobby]

Only codes I've had are "dipped beam faulty" in the past - but I will check them again over the weekend, dipped beam is high beams no? They weren't on