Audi A4 8E: Parts, Accessories & More

Hey everyone,
I'm a bit frustrated right now and wanted to see if anyone else has had a similar experience.

I have extracted configuration data from my A4 B7 (8E) -07 Avant, and I have identified the IDs for the passenger-side mirror and window. Using these IDs, I am now able to control them.
"However, I receive no signal on the driver's side."

I also tried a desperate measure: I erased all data from the "comfort bus" system and then replayed it. This restored the functionality of the window controls and mirror adjustments for the passenger side, but everything remains silent on the driver's side.

"I also tested the key fob window controls; they operate up and down as expected, but when I try to replay the recordings, there is absolutely no effect on the driver's side window."

"Do you have any idea why?" or "Can you think of a reason why?"

To confirm, I tested another A4 Avant with a slightly different configuration than mine, and it exhibits the exact same behavior. The passenger side works correctly, but nothing happens on the driver's side door.

Okay, for clarification.
* I'm getting signals from the right side that are being sent to the instrument cluster (comfort, information, engine).
* And I've tried connecting the CAN bus cables directly to the driver's side module without any success.
* I've tried various approaches with window module buttons using LIN transceivers, but haven't had any success.

Overall, I've tried sending all values from 1 to FF to all the bytes that my device can transmit (which is only 2 bytes), and only the first byte with the values 10, 20, 40, and 80 triggers the passenger window. However, the logs don't show any of the values 01, 02, 04, or 08, which I found from other sources that claim successful driver door control. Injecting these values has no effect in my car.

In the Audi A5 facelift, there's a single ID used to control all the window functions. This might be compatible with the Audi A4 B8, but it could be different in your specific Audi model.

But I didn't test it with mirrors... only with windows.

"Another approach is to use four IDs that correspond to the position of each window. This way, you always know the exact position of all the windows."

Perhaps controlling the driver-side mirror via a CAN message wasn't the original design intention. In what scenario would another Electronic Control Unit (ECU) attempt to control the driver-side mirror? I suspect that the necessary CAN message for this functionality hasn't been implemented.

Surfjenser wrote:

Maybe it wasn't intended to control the driver mirror using a CAN message. In which scenario would another ECU aim to control the driver mirror? I assume that the corresponding CAN message is not implemented.

As far as I know, it's possible to control the retractable mirrors on a VW Passat B7 using a CAN message. I don't have any information about how to change the "view angle."

Thank you for your replies .
Okay, I've identified a potential parameter for positioning, but when I tried injecting values into it, nothing happened. This suggests that it might not be the correct parameter to use for controlling the behavior.

I also initially thought there wouldn't be a dedicated control for the driver's window because it seemed unnecessary, but there actually is a function that triggers the windows. Specifically, when using the key fob's alarm/disarm buttons, I can raise and lower both windows simultaneously.

Interestingly, when I record the CAN bus data traffic while simultaneously pressing and holding the key fob button and the windows are operating, and then replay that recorded data back onto the bus, nothing happens.

I assume there's an ID (or perhaps several related IDs) that trigger the driver window to appear.
I think it's probably difficult to find it, or to decipher the combination between those completely unknown identifiers.