Fault code 4460 - Pressure sensor. ABS/PSM warning lights on

[Cabrio]

Hello 986 fans,

my first post, and I'm coming right away with a problem :-).

I bought a Porsche Boxster last month. It's a 2004 FL 5 Speed ​​with 58,000 km (garage car and only used in summer).

According to the previous owner (for about two years), the car has the following problem:
When driving (straight ahead), the ABS and PSM warning/error lights come on at exactly 31 mph (50 km/h). This makes a noise similar to an electronic parking brake. After turning off the car, the error disappears (but is stored in the error log).

What the previous owner has already done at a workshop (not a Porsche workshop):

- ABS sensor check (previous owner couldn't comment on this, so I still need to check the sensors)
- Brake pressure sensor replaced
- ABS control unit removed and checked at a specialist control unit workshop - no faults found.

I installed a new, original Porsche brake light switch, as well as
- new battery
- alternator regulator delivering normal readings (around 14 volts)
- new tires (still on from the previous owner - very old) - Porsche-approved tires
- fresh brake fluid

Unfortunately, the problem still persists; that would have been too easy.

According to Durametric, the following error message is displayed:

Fault code 4460 - Pressure sensor

I found the following solution:
https://rennkit.com/wp-content/uploads/2018/06/996TT-DIAGNOSTIC-MANUAL-2.pdf starting on pages 108 and 109
and
https://www.pff.de/wcf/file-download/419292/

I performed the following measurements:



1.) Plug connection on the brake pressure sensor is clean and free of corrosion

2.) Check supply voltage of the pressure sensor for short circuit to groound/ open circuit: approx. 5 V ---> 4,98V

3.) Check ground of pressure sensor for open circuit: approx. 5 V ---> 4,99V

4.) Check signal lead of the pressure sensor for short circuit to voltage: < 0.3 V ---> 0 V

5.) Check signal lead of the pressure sensor for short circuit to Ground: < 5 Ω ---> ∞ Ω (some Papers says here "∞ Ω" ??? https://www.pff.de/wcf/file-download/419292/)

6.) Check signal lead of the pressure sensor for open circuit: < 5 Ω ---> ∞ Ω


I carefully cut open the nylon hose from the ABS control unit connector and couldn't find any broken wires.

My questions:
Can someone tell me the correct value under point 5.)?
How can I resolve the apparent broken wire under point 6.)? Simply run another new wire in parallel?

I'm also a bit confused: I reported the error and the measurements to my Porsche workshop. At first, they thought it was the tires. After confirming that the correct tires were mounted, they suggested it might be the ABS sensors after all. Unfortunately, I didn't get an answer to my question about what the ABS sensors had to do with error 4460.

I'm grateful for any help.

Best regards, cabrio