Headlight Failure Service Requird

[ferg55]

Originally Posted by Pidgeonpost

The headlights. Again, I'm going to show my ignorance as I don't know the type of headlight. They don't do any of the fancy manoeuvres that they did on our BMW or Skoda, and there's no rotary control for headlight adjustment shown in the handbook.

https://postimg.cc/GT9J3N9L

Are you able to determine the type from that perhaps?

They are the bi-xenon's. Bi as in 2 x bulbs, one xenon (for dipped) and one halogen (works with the xenon bulb, on high beam only). Depending on spec, you have either "active bending lamp" (ABL) version - which turn with the steering when dark, or just non-ABL versions. That can be confirmed with the presence of the ABL on/off switch in the center consul which is a lamp icon with arrows left / right to depict them turning. But either type should do an up/down movement on start up, which is the automatic leveling feature. If they aren't, may be as simple as a plastic level rod popped off under a front or rear wheel arch, connects to the suspension and body to measure ride height and adjusts the headlamp level accordingly.

[Pidgeonpost]

Thanks for all your helpful suggestions folks. Hoping to get some time in the next couple of days to check some of these things out and will report back.

[Pidgeonpost]

Okay, I got a bit of slack on the leash today so decided to have another look at possible causes.

First the battery. I'm no further forward on knowing its age, but as the car is almost 15 years old i suspect it's the second battery at least.
I'd hoped to do a 'resting test' to check the voltage after standing all night, but I'd put the car away nose first, and there's not enough room to get the bonnet up in our oddly shaped garage. The best I could do was to check it when it had been standing 5 and a half hours. The meter reported 12.69v at that point, and on starting the engine it showed 14.03v. I thought most alternators pushed out about 14.4v, but not sure on that. Whatever the age/state of the battery it cranks the car over well so I'll be leaving it in place for the time being unless something else points to a failing battery.

On to the headlights themselves. Why aren't all headlights as easy to remove as these? There was no sign of damage or loose wires within the headlight units, but I bottled out of unplugging the plugs on the motors as it looked like it would be a right fiddle to get them back on. I didn't have time to remove the motors if reconnection proved difficult, and didn't want another error logged at this stage. I didn't have an assistant to check for movement of the motors unfortunately, but I know from looking at the light pattern on the wall that there is no movement of the lights when switched on. I know I've seen the beams adjusting before. The car was serviced a couple of weeks ago, but I can't remember whether I noticed this before or since the service. It's a b****r getting old! Anyway, they aren't doing it now. Couldn't be something as simple as a fuse I guess?

Thanks @ferg55 for clarifying what the lights are. I can confirm that there's no ABL switch on the console, and I see from the service record that one HID bulb was replaced in 2020, but it doesn't say which one. It was £70. The halogen main beam bulbs are Philips 55Watt jobs. I guess I'll wait and see how they perform once I overcome the lack of movement business.

All a bit inconclusive really, more of a familiarisation exercise. I was going to go for a drive in complete darkness tonight, but I've just had a beer so that'll have to wait. Cheers!

[Pidgeonpost]

Progress to date - not a lot.

Regarding the 'Headlight failure' message being linked to a flat or failing battery, after 36 hours of not being used the battery had a resting voltage of 12.38 volts, or about 75% charged if Google can be believed. Not brilliant, but perhaps not unreasonable given the number of short journeys over the last few weeks. Maybe an overnight charge wouldn't hurt.

As to the headlight levelling, I must have been mistaken in thinking that no levelling is taking place, because it is. I noticed last night that if I only turned the ignition on (engine off), followed by the headlights, I could hear a low-frequency hum and see the beam pattern changing as the lights began levelling, both beam patterns were moving in parallel, first rising, and then lowering again. Obviously this was the levelling motors in both headlights doing their thing. The movement to establish the final level wasn't a smooth continuous one though, it was interrupted several times during the process before resuming. I'd be interested to know if others get these interruptions of the levelling process or if it's normal.

I've yet to be able to drive the car in full darkness to judge how effective the low beams really are. Until I can do that my other option is to have a look at the levelling sensors, as suggested earlier. Am I right in thinking there are just 2 sensors, one front, one rear? Nearside or offside? I don't want to waste time taking the wrong wheels off.

As mentioned before, Car Scanner app shows no codes, I don't have Vida or know anyone locally who does.

[Pidgeonpost]

Quick update on this:

1. A short late-night drive proved that the lights settle in a position that's far too low.

2. Removed nearside wheels to find nothing that even remotely resembles the online images of the leveling sensors.

Might give my indie a ring today.

[37 RUBY]

Originally Posted by Pidgeonpost

Quick update on this:

1. A short late-night drive proved that the lights settle in a position that's far too low.

2. Removed nearside wheels to find nothing that even remotely resembles the online images of the leveling sensors.

Might give my indie a ring today.

The level sensor at the front is on the off side and the rear unit whilst on the nearside is inboard of the wheel hub and can be seen from under the car rather than from wheelside.

[Pidgeonpost]

Originally Posted by 37 RUBY

The level sensor at the front is on the off side and the rear unit whilst on the nearside is inboard of the wheel hub and can be seen from under the car rather than from wheelside.

Thank you, thank you!

Had another look this morning and it seems these sensors are a moveable feast as both front and rear are on the offside on our car.
I could see nothing adrift on the rear one, but on the front one the longer arm that connects to arm on the sensor was disconnected and pushed to one side. The pin or bolt (too rusty to tell) that passes through the arms has a flexible bush which was in a bad way and refused to push back into place fully, so I've used a cable tie for now. Don't think it will last long, but maybe until I can get a new switch or arm.

Thanks also to @ferg55 for suggesting this possible cause several posts back.