One other thought is that the solenoid could be bad too.

 

Tim,
If you have no power when in the car check the dedicated fuse & relay for the PSD - behind the plastic cover above and in front of (car) the battery box. This is fed directly from the battery - not connected through the main fuse panel.

Alan

 

And one other item....

The ABS and PSD system share a single control unit and the PSD uses the ABS wheel speed sensors. If there is an ABS fault the PSD system will shut off.

Do you have ABS faults?

 

Alan, thanks that's the answer to #1

Andrew, you might have something there with a possible obstruction.

As for ABS Faults? not that I know of. The car has been parked for several months.
I'm a bit confused by the flush procedure because in the version I downloaded it instructed to open the bleader valve and then reconnect the power to the pump with the ingition key in the second position, then the new fluid would start to move through the system. This is differen from what Dave C was saying. Probubly doesn't make much difference as the pump should...pump.

I will resolve this eventually. in the meantime Happy Easter,Passover, ect. to everyone.
Cheers
Tim

 

Ignition On is position #2. Ignition in position #3 would run the starter.

So #2 (On) is correct.

The pump should run until the pressure switch's threshold is reached if the ignition is on. If you have released the pressure from the solenoid, and with the ignition on, the pump does not run or make any sound at all when connected then obviously there's an issue. I would think that either the pump isn't getting power or it is dead. Or perhaps the pressure switch is dead and telling the pump not to run. Otherwise, I would think that the pump would make some kind of noise when powered even if there was some blockage?

Power to the pump runs through the relay. The relay is switched on or off by the pressure switch. So, if you are bench testing the pump with direct 12v and it makes no noises of any kind, I would think that's a good indication that the pump is dead?

 

You are correct. My previous summary left out the very first step (#17, bottom of page 5) where you allow the pump to run with the bleeder open.

So, to re-summarize:

- Run the pump with the bleeder open until the fluid is clear.
- Then you close the bleeder and bleed the accumulator as in my previous post and as described in steps #18 through #20 until the fluid is clear.

 

Hey Dave:

That's where I'm at right now. Bench testing, power applied, pump runs, but doesn't flow fluid with the bleeder open as suggested in my version of directions. However the directions are for the unit still installed in the car with the "control cable still connected".

I'm just going to reinstall the whole system and try it all again.

T

 

Oops. Sorry. I misread your post where you wrote that the pump was running. My Bad.

The only other connection is - I think - the connector for the pressure switch. Right? (You have it on a bench I don't.)

I'm with Andrew: blockage?

 

Hi
Please show me where can I find Luis and John method to fix the PSD problem
Thanks

 

Louis Ott Procedure:
https://928srus.com/pages/psd-fluid-flushing-procedure

Porsche TSB info and other helpful proceedures
https://drive.google.com/file/d/1hYv...usp=drive_link

Porsche Overview of PSD system
https://drive.google.com/file/d/1tYz...usp=drive_link

Porsche Tech Specs
https://drive.google.com/file/d/1S9y...usp=drive_link

 

Please give me some advise where can I find Louise and John method
thx

 

please review the link on my post above