Xenon slight flicker under braking
 

Over the past few weeks, I'd swear I saw a flicker in the Xenons, but I thought maybe it didn't happen and I was just losing it or my eye flickered weird. Tonight I drove out of a driveway head first and as I hit the brakes, I saw the flicker. I brushed it off as an eyeball thing again. When I got home and hit the brakes to stop (just a sharp stab), it flicked again. I was able to figure out it was the right light and was able to get it to flicker 8/10 times (neighbours probably thought I was an idiot backing down my driveway and speeding towards my garage door, slamming on the brakes. Repeatedly :) ).

Any ideas on where to start looking? I tried to tap the light with my first to see if something was loose. The one connector seemed good too.

Could be control unit, ignition element or bulb. I'm suspecting not the LCM as it is only one side. That being said, i did notice the driver's side angel eye flicker on start up the other day too. I could be in for an adventure.

Thanks in advance for any insight.

Does the same thing happen when you gently apply the brakes?

My reason for asking is to help diagnose. Is it some kind of voltage leak, or the brake light circuit somehow affecting the headlight circuit?

Or does it only occur with "vigorous" application of the brakes - which could indicate a connection issue, as components move around.

Seems more with a jab on the brakes, not mild application. Nothing seemed remotely loose in the headlight area. There was the one connector that I pressed/pulled on and it didn't move. Banging the assembly yielded no flicker. I could try banging it in the direction of travel to see if it's triggered by momentum of the assembly itself. At least I'm on to the start of being able to repeat it.

Mate, I'd be disconnecting and cleaning every electrical connection in the headlight circuit. Throw in a visual inspection to look for terminals that might not be making full contact due to being spread too far open. It's not the physical connector block per-se, its the wiring inside that is the potential issue.

Thanks for the tips. I'm on to it now, so I'll keep at it until I have it solved. I do have to pull off the bumper to redo a side clip, so I may pull the whole assembly out to really dig into it. Next weekend I have a pile of car repairs queued up across 3 vehicles - hopefully I have time to look at the headlight.

Cheers.

Had a few minutes tonight. Pulled out the air intake to get some good access to the headlight housing. Tapped, banged, bumped the assembly and module underneath and couldn't replicate it. Disconnected and reconnected the connector as well. Tapped the wiring that I could see in the engine bay too to see if there was a loose or shorted wire. Not a flicker. Came home and sure enough saw the flicker as I braked into the driveway. So weird. I'll plug in the computer on the weekend and see if there are any codes.

Very, very weird. When the vehicle is stationary and the brakes are applied, no flicker? When the vehicle is moving, and only small amount of braking is applied, no flicker?

Correct on both accounts.

All says to me there has to be some issue with electrical connectivity.

Might be a long shot, but have you tried replacing the fuse(s) with brand new ones? Headlight relay/s the same?

I am loathe to throw parts at a problem in an attempt to fix it, but 'lectric issues are damned hard to diagnose on the other side of the planet :)

Might be worth a check further back in the harness - fuse block etc.

Is it both sides that flicker or just one?

Edit: sorry, you said in your first post just one side. That is good. Means you can start swapping individual components and see if the symptom follows a particular component.

Try the brake light stop switch by the pedal

I'll crack the schematis and see what I'm dealing with. What are your thoughts on the pedal switch? I thought of the same, but it is only on heavier braking, not all the time.

In theory, there should be no correlation between the headlights and the braking light circuit.

With the brake light switch, it is also a simple device - open or closed. It is not variable, so the amount of braking effort shouldn't bother it. Otherwise (for example) sitting in your driveway with your foot mashed to the floor on the brake pedal could produce the flicker.

My thoughts are now gravitating towards it being a crook ballast.

Ballasts interchangeable? :)

Honestly, I have absolutely no freakin' idea. Certainly worth looking at the connectors though. Ballasts are generally not specific to one side.

You could swap the ballasts side to side, if the flicker follows the ballast then you kbow