ABS light on (without parking brake light)

[WildChild]

I just removed the sensor to take a look at it. The sensor itself was covered with drips of rust. Looking inside the hole, there was also a lot of rust. Could it be a cause for "foreign material on sensor"? Is this sensor supposed to be completely sealed to protect the inside? I'm not sure if I saw rust in there when I removed the sensor on the other side a few weeks ago.

After cleaning the sensor and putting it back, clearing the code, the ABS light came back within 100 meters, again with a 35 code.

I will check the sensor for continuity later tonight or tomorrow. If the sensor itself looks good and there isn't supposed to be rust there, what parts could need replacement?

Thank you!