Windshield Washer Fluid Warning Not Working

I retrofitted the FIS (driver information system) to my A4. During the installation, I also integrated the windshield washer fluid warning system.

According to the wiring diagram, the cable runs from pin 9 of the 20-pin connector to the sensor in the water tank, and from there to ground. However, the FIS (presumably a vehicle information system) is not displaying a water level warning, regardless of whether the cable is connected to the sensor or not.

The warning is encoded.

How does the FIS actually detect the water level? Does it pass 12 volts through the sensor to ground via pin 9, or does it simply detect whether a ground connection exists?

I briefly, and accidentally, connected the power signal to pin 9. Could I have damaged the connection?

Hello bastion,

According to the wiring diagram, the warning contact for the windshield washer fluid connects to ground.
Whether this applies when the tank is full or empty is not specified in the plan .

You can safely connect wire 9 to ground or leave it open (but do not connect it to 12 volts) instead of using the potentially faulty sensor for testing.

Nothing can happen.

Best regards, Kassen.

It switches to "full" when the tank is full. I'm just worried that I accidentally connected it to the fuel consumption signal at some point.

The problem is that the warning light never comes on, whether it's connected or grounded.

Is the AI coding correct?

Dear de.openodb.org:

Code:

STG 17 (Kombiinstrument) auswählen STG Codierung -> Funktion 07 ??xxx: Extra-Optionen und Mehrausstattungen (bis MJ 2000) +00 - keine Mehrausstattung +01 - Bremsbelagverschleißanzeige aktiv +02 - Sicherheitsgurtwarnanzeige aktiv +04 - Waschwasseranzeige aktiv 6 - Navigation aktiv

Regards,
Peter.

Yes, that's correct. I coded it myself and then had it coded again at a workshop. It didn't change anything.


Edit:
On which pins of the 20-pin connector is the brake pad wear indicator located?