Audi A6 C6 Headlight Leveling System

After I replaced the suspension, I wanted to readjust the leveling. The result is:

Address 55: Headlight range adjustment. Label file: DRV\8P0-907-357.lbl
Part number: 8P0 907 357 F
Component: Dynamic Left Wheel Rail (LWR), H02 0010.
Revision: 00000001 Serial number:
Encoding: 0000003
Operating number: WSC 02325 758 00200
VCID: 3D770FF1643A1763E8-8068

Sure, here is the translation of the text from German to English:

"1 error found:"
01539 - Headlights not adjusted.
005 - No or incorrect initial setting/adaptation - Warning light ON.
Environmental conditions:
Error status: 11100101
Error priority: 2
Error frequency: 1
Lost Count: 160
Mileage: 322,616 km
Time: 0
Date: 2021.10.06
Time: 14:39:56

All SG are 4F. I suspect that the wrong type of SG (Sicherheitsglas / safety glass) was installed here.

Good evening, Andreas,

The current part number for any A6 C6 is...

8P0 907 357 M.

The control unit is generally in good working order.

If you want to know exactly, you would need to tell me more about the vehicle.

Are the level sensors within the tolerance range and have they not been damaged?

Can the error be cleared and the default settings restored?


Best regards,

Michael.

Ich_Can_nix wrote:

Are the level sensors within the tolerance range and have they not been damaged?

How can I find that out? I can't imagine that the front sensor is still intact after over 300,000 kilometers.

Ich_Can_nix wrote:

Can the error be cleared and the default settings restored?

Errors can be deleted. After performing the initial setup, the error occurs again.

Incidentally, the brightness of the xenon headlights is quite poor. They definitely need new bulbs. The lenses also seem to be dusty. How do you get these verschandeln again?

Hello Andreas,

Your control unit is programmed for an A6 4F model with a steel suspension and xenon headlights without cornering lights.

Does that match the equipment on the vehicle?

The sensors should operate within a voltage range of 1.5 volts to 3.5 volts (front) and 0.5 volts to 4.5 volts (rear).

In the MWB documentation, they are represented as G76 and G78. Here, the value is specified in millimeters. Ideally, the value should change when you adjust the vehicle's height.

Would you like me to perform an auto-scan?
provide?

Best regards,

Michael.

Hello Michael,

Ich_Can_nix wrote:

Your control unit is programmed for an A6 4F model with a steel suspension and xenon headlights without cornering lights. Does that match the equipment on the vehicle?

That is correct.

I find it's best to test the sensors when they are not yet installed. Does this model not explicitly indicate when faulty sensors are detected?

Good evening, Andreas,

In principle, VCDS should be able to detect defective sensors. You are right.

Your control unit is currently expecting a basic configuration from you.

It seems that your default setting WAS NOT accepted.


What happens when you perform the default settings reset, or what message appears?


Does the message "Rule set learned" appear?



I happened to have an identical one in the workshop; I'd be happy to try it out tomorrow if you're still stuck.


Best regards,

Michael.

Hello Michael,

Okay, the message says "Rule set learned," but apparently the system (SG) doesn't accept the default settings.

It's also possible that, in that specific production batch, the implementation of the system wasn't advanced enough to detect defective sensors. But rather, they must be reviewed by the MWB.

Could it be that the SG is defective? Where is it located?

Tomorrow, the A6 will be back here, and I'll be able to test it.

Hello Andreas,

The control unit is located behind the glove compartment.

In addition, there are connectors located in the right A-pillar for the headlight actuators (left and right), as well as for the front vehicle level sensor.

I just found this in the documentation for the adaptation channels:

Channel 008: Sensor plausibility.
0 = Sensor plausibility error, system locked.
1 = Sensor plausibility error released.

If you are not familiar with the vehicle, it might be helpful to go through the adjustment channels.

Best regards,

Michael.

Ich_Can_nix wrote:

Channel 008: Sensor plausibility. 0 = Sensor plausibility error, system locked. 1 = Sensor plausibility error released.

I have already located and enabled the channel. Since then, the error has also appeared in the FIS.

Very strange. I once had the opportunity to record the movement of the sensors in millimeters using the MWB (presumably a specific device or software). After that, I received an error message indicating that the sensors could not be addressed. After clearing this error message, the situation remained unchanged during the logging process. Front: 0 mm. Rear: 0 mm.

For me, both sensors are definitely broken, which isn't surprising considering the mileage of 323,000 km.

Are there any other potential sources of error that I can check in advance?

Hello Andreas,

Then you've probably narrowed down the source of the error quite a bit.

If everything else responds during the actuator test, then the problem is likely either the contacts/connectors on the sensors or the sensors themselves.

The address error might also indicate the use of cheaper, aftermarket sensors.


Best regards,

Michael.

The sensors might also be outside the specified range due to the new suspension components (lowered ride height?, different mounting points?).
hg
Herbert.

Okay, things are getting strange: I disconnected the sensors and manually moved them. Lo and behold, they're working, the system allows the basic settings, and there are no more error messages. Even during the test drive, the relevant vehicle data provided plausible values.

I hope it stays that way. I cannot say why this error occurred or why it has not reappeared since the manual intervention, as I have not done anything other than running the limit switches.

As expected, the error reappeared today. Let's see what the log says this time. It's probably most sensible to replace both sensors.