P1209 Code: Brake Booster Vacuum Sensor Part #?

[carguy750]

Hey guys, I recently flushed my brake fluid and fluid must have leaked down to the brake booster vacuum sensor according to multiple threads experiencing the code my M3 is throwing (P1209).

Does anyone know a link to the sensor that needs replacing. I was able to find a part from other threads (https://www.ecstuning.com/b-genuine-...e/34302283605/) but this seems to be more than just the sensor.

[notouching]

Had the same issue last fall. Couldn't find just the sensor part #, so ordered the whole line with the sensor, and only used the sensor itself.

This extension + torx bits helped me a ton in that job:
https://www.amazon.com/gp/product/B074V3NDTP/

[carguy750]

Originally Posted by notouching

Had the same issue last fall. Couldn't find just the sensor part #, so ordered the whole line with the sensor, and only used the sensor itself.

This extension + torx bits helped me a ton in that job:
https://www.amazon.com/gp/product/B074V3NDTP/

Gotcha. Were you able to replace the sensor without removing the master cylinder/having to bleed the brakes again?

[GotV8?]

I had same issue when flushed out my brakes also last summer, OP, you are better off ordering the entire unit above and just replace it...if you plan to DIY, I hope you have small hands, its very tight and time consuming to swap out, you will have to a lot of wiggling. goodluck.

[notouching]

Originally Posted by williyam

Gotcha. Were you able to replace the sensor without removing the master cylinder/having to bleed the brakes again?

Yeah with the help of this extension it wasn’t bad.
Make sure the torx bit is magnetic so you don’t lose the bolts.
I had to unscrew the brake fluid reservoir and move around some lines, but it wasn’t bad, took 40 min.
Search for a thread by MEMPH1S, he had one with lots of details.